diff --git a/.gitignore b/.gitignore
index 7e0e151c..1d25926a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,17 +1,18 @@
-c64/basic/OUT.BIN
-c64/basic/combined.s
-c64/kernal/OUT.BIN
-c64/kernal/combined.s
-chargen
-newbasic
-newc65
-newkern
-newrom
-ophis.bin
-padding
-src/collect_data
-src/compress_text
-src/pngprepare
-src/preprocess
-temp.map
+
+# Compilation related files
+
 temp.s
+temp.map
+
+ophis.bin
+build/*
+
+# Input to the similarity tool - copyrighted material, we can't check it in!
+
+/basic
+/kernal
+
+# Various IDE project files, temporary files, etc.
+
+*project
+.*swp
diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
new file mode 100644
index 00000000..2bb826fe
--- /dev/null
+++ b/CONTRIBUTORS.md
@@ -0,0 +1,2 @@
+
+Although the project itself is LGPL3, I (FeralChild64) allow to redistribute my contributions to this project under any OSI (Open Source Initiative) approved open source license.
diff --git a/Makefile b/Makefile
index 92d15cae..7e68ac85 100644
--- a/Makefile
+++ b/Makefile
@@ -1,61 +1,157 @@
-all:	Ophis src/collect_data src/preprocess
+
+# Source files
+
+SRC_COMMON            = $(wildcard c64/aliases/*.s)
+SRC_BASIC_COMMON      = $(SRC_COMMON) $(wildcard c64/basic/*.s)
+SRC_KERNAL_COMMON     = $(SRC_COMMON) $(wildcard c64/kernal/*.s c64/kernal/jumptable/*.s c64/kernal/iec/*.s)
+
+SRC_BASIC_generic     = $(SRC_BASIC_COMMON) $(wildcard c64/basic/,target_generic/*.s)
+SRC_BASIC_mega65      = $(SRC_BASIC_COMMON) $(wildcard c64/basic/,target_mega65/*.s)
+SRC_BASIC_ultimate64  = $(SRC_BASIC_COMMON) $(wildcard c64/basic/,target_ultimate64/*.s)
+
+SRC_KERNAL_generic    = $(SRC_KERNAL_COMMON) $(wildcard c64/kernal/,target_generic/*.s)
+SRC_KERNAL_mega65     = $(SRC_KERNAL_COMMON) $(wildcard c64/kernal/,target_mega65/*.s)
+SRC_KERNAL_ultimate64 = $(SRC_KERNAL_COMMON) $(wildcard c64/kernal/,target_ultimate64/*.s)
+
+# List of tools
+
+TOOL_COLLECT_DATA  = build/tools/collect_data
+TOOL_COMPRESS_TEXT = build/tools/compress_text
+TOOL_PNGPREPARE    = build/tools/pngprepare
+TOOL_PREPROCESS    = build/tools/preprocess
+TOOL_SIMILARITY    = build/tools/similarity
+
+TOOLS_LIST = $(TOOL_COLLECT_DATA) $(TOOL_COMPRESS_TEXT) $(TOOL_PNGPREPARE) $(TOOL_PREPROCESS) $(TOOL_SIMILARITY)
+
+# Rules - main
+
+.PHONY: all clean updatebin
+
+all: build/chargen build/newkern_generic build/newbasic_generic build/newc65 build/newkern_ultimate64 build/newbasic_ultimate64
 
 Ophis:
 	git submodule init
 	git submodule update
 
-src/pngprepare:	src/pngprepare.c Makefile
-	$(CC) $(COPT) -I/usr/local/include -L/usr/local/lib -o src/pngprepare src/pngprepare.c -lpng
+clean:
+	@rm -rf build
+	@rm -f temp.s
+	@rm -f temp.map
+	@rm -f ophis.bin
 
-chargen:	src/pngprepare assets/8x8font.png
-	src/pngprepare charrom assets/8x8font.png chargen
+updatebin: build/chargen build/newbasic_generic build/newkern_generic build/newbasic_mega65 build/newkern_mega65 build/newbasic_ultimate64 build/newkern_ultimate64
+	cp build/chargen                  bin/chargen.rom
+	cp build/newbasic_generic         bin/basic_generic.rom
+	cp build/newkern_generic          bin/kernal_generic.rom
+	cp build/newbasic_mega65          bin/basic_mega65.rom
+	cp build/newkern_mega65           bin/kernal_mega65.rom
+	cp build/newbasic_ultimate64      bin/basic_ultimate64.rom
+	cp build/newkern_ultimate64       bin/kernal_ultimate64.rom
 
-src/collect_data:	src/collect_data.c Makefile
-	gcc -Wall -o src/collect_data src/collect_data.c
+# Rules - tools
 
-src/preprocess:	src/preprocess.c Makefile
-	gcc -g -Wall -o src/preprocess src/preprocess.c
+$(TOOL_COLLECT_DATA): src/collect_data.c Makefile
+	@mkdir -p build/tools
+	gcc -Wall -o $(TOOL_COLLECT_DATA) src/collect_data.c
 
-src/similarity:	src/similarity.c Makefile
-	gcc -g -Wall -o src/similarity src/similarity.c
+$(TOOL_COMPRESS_TEXT): src/compress_text.c Makefile
+	@mkdir -p build/tools
+	gcc -g -Wall -o $(TOOL_COMPRESS_TEXT) src/compress_text.c -lm
 
-src/compress_text:	src/compress_text.c Makefile
-	gcc -g -Wall -o src/compress_text src/compress_text.c -lm
+$(TOOL_PNGPREPARE): src/pngprepare.c Makefile
+	@mkdir -p build/tools
+	$(CC) $(COPT) -I/usr/local/include -L/usr/local/lib -o $(TOOL_PNGPREPARE) src/pngprepare.c -lpng
 
-newrom:	c64/kernal/OUT.BIN c64/basic/OUT.BIN
-	cat c64/basic/OUT.BIN c64/kernal/OUT.BIN  >newrom
+$(TOOL_PREPROCESS): src/preprocess.c Makefile
+	@mkdir -p build/tools
+	gcc -g -Wall -o $(TOOL_PREPROCESS) src/preprocess.c
 
-newkern:	newrom Makefile
-	dd if=newrom bs=8192 count=1 skip=2 of=newkern
+$(TOOL_SIMILARITY): src/similarity.c Makefile
+	@mkdir -p build/tools
+	gcc -g -Wall -o $(TOOL_SIMILARITY) src/similarity.c
 
-newbasic:	newrom Makefile
-	dd if=newrom bs=8192 count=1 skip=0 of=newbasic
+# Rules - CHARGEN
 
-newc65:		newkern newbasic chargen Makefile
-	dd if=/dev/zero bs=4096 count=10 of=newc65
-	cat newbasic chargen chargen newkern >>newc65
-	dd if=/dev/zero bs=65536 count=1 of=padding
-	cat padding >>newc65
+build/chargen: $(TOOL_PNGPREPARE) assets/8x8font.png
+	$(TOOL_PNGPREPARE) charrom assets/8x8font.png build/chargen
+
+# Dependencies
+
+build/basic_generic/OUT.BIN:  Ophis $(TOOLS_LIST) $(SRC_BASIC_generic) build/basic/packed_messages.s
+build/kernal_generic/OUT.BIN: Ophis $(TOOLS_LIST) $(SRC_KERNAL_generic)
+build/newrom_generic:   build/basic_generic/OUT.BIN build/kernal_generic/OUT.BIN
+build/newkern_generic:  build/newrom_generic Makefile
+build/newbasic_generic: build/newrom_generic Makefile
+
+build/basic_mega65/OUT.BIN:  Ophis $(TOOLS_LIST) $(SRC_BASIC_mega65) build/basic/packed_messages.s
+build/kernal_mega65/OUT.BIN: Ophis $(TOOLS_LIST) $(SRC_KERNAL_mega65)
+build/newrom_mega65:   build/basic_mega65/OUT.BIN build/kernal_mega65/OUT.BIN
+build/newkern_mega65:  build/newrom_mega65 Makefile
+build/newbasic_mega65: build/newrom_mega65 Makefile
+
+build/basic_ultimate64/OUT.BIN:  Ophis $(TOOLS_LIST) $(SRC_BASIC_ultimate64) build/basic/packed_messages.s
+build/kernal_ultimate64/OUT.BIN: Ophis $(TOOLS_LIST) $(SRC_KERNAL_ultimate64)
+build/newrom_ultimate64:   build/basic_ultimate64/OUT.BIN build/kernal_ultimate64/OUT.BIN
+build/newkern_ultimate64:  build/newrom_ultimate64 Makefile
+build/newbasic_ultimate64: build/newrom_ultimate64 Makefile
 
 
-c64/basic/packed_messages.s:	Makefile src/compress_text
-	src/compress_text > c64/basic/packed_messages.s
+# Rules - BASIC and KERNAL
 
-c64/kernal/OUT.BIN:	src/preprocess c64/kernal/*.s
-	src/preprocess -d c64/kernal -l e4d3 -h ffff
+build/basic/packed_messages.s: $(TOOL_COMPRESS_TEXT)
+	@mkdir -p build/basic
+	$(TOOL_COMPRESS_TEXT) > build/basic/packed_messages.s
 
-c64/basic/OUT.BIN:	src/preprocess c64/basic/*.s c64/basic/packed_messages.s
-	src/preprocess -d c64/basic -l a000 -h e4d2
+.PRECIOUS: build/basic_%/OUT.BIN
+build/basic_%/OUT.BIN: Ophis $(TOOLS_LIST) $(SRC_BASIC_$*) build/basic/packed_messages.s
+	@mkdir -p build/basic_$*
+	@rm -f build/basic_$*/*
+	@for SRC in $(SRC_BASIC_$*); do \
+	    ln -s ../../$$SRC build/basic_$*/$$(basename $$SRC); \
+	done
+	@ln -s ../../build/basic/packed_messages.s build/basic_$*/packed_messages.s
+	$(TOOL_PREPROCESS) -d build/basic_$* -l a000 -h e4d2
 
-testremote:	newkern newbasic
-	x64 -kernal newkern -basic newbasic -remotemonitor
+.PRECIOUS: build/kernal_%/OUT.BIN
+build/kernal_%/OUT.BIN: Ophis $(TOOLS_LIST) $(SRC_KERNAL_$*)
+	@mkdir -p build/kernal_$*
+	@rm -f build/kernal_$*/*
+	@for SRC in $(SRC_KERNAL_$*); do \
+	    ln -s ../../$$SRC build/kernal_$*/$$(basename $$SRC); \
+	done
+	$(TOOL_PREPROCESS) -d build/kernal_$* -l e4d3 -h ffff
 
-test:	newkern newbasic
-	x64 -kernal newkern -basic newbasic -8 empty.d64
+.PRECIOUS: build/newrom_%
+build/newrom_%: build/basic_%/OUT.BIN build/kernal_%/OUT.BIN
+	cat build/basic_$*/OUT.BIN build/kernal_$*/OUT.BIN  > build/newrom_$*
 
-testm65:	newc65
-	m65 -b ../mega65-core/bin/mega65r1.bit -k ../mega65-core/bin/KICKUP.M65 -R newc65 -4
+.PRECIOUS: build/newkern_%
+build/newkern_%: build/newrom_% Makefile
+	dd if=build/newrom_$* bs=8192 count=1 skip=2 of=build/newkern_$*
 
-testsimilarity:	newkern newbasic src/similarity
-	src/similarity kernal newrom 
-	src/similarity basic newrom 
+.PRECIOUS: build/newbasic_%
+build/newbasic_%: build/newrom_% Makefile
+	dd if=build/newrom_$* bs=8192 count=1 skip=0 of=build/newbasic_$*
+
+# Rules - platform 'Mega 65' specific
+
+build/newc65: build/newkern_mega65 build/newbasic_mega65 build/chargen Makefile
+	dd if=/dev/zero bs=4096 count=10 of=build/newc65
+	cat build/newbasic_mega65 build/chargen build/chargen build/newkern_mega65 >> build/newc65
+	dd if=/dev/zero bs=65536 count=1 of=build/basic/padding
+	cat build/basic/padding >> build/newc65
+
+# Rules - tests
+
+test: build/newkern_generic build/newbasic_generic
+	x64 -kernal build/newkern_generic -basic build/newbasic_generic -8 empty.d64
+
+testremote: build/newkern_generic build/newbasic_generic
+	x64 -kernal build/newkern-generic -basic build/newbasic-generic -remotemonitor
+
+testm65: build/newc65
+	m65 -b ../mega65-core/bin/mega65r1.bit -k ../mega65-core/bin/KICKUP.M65 -R build/newc65 -4
+
+testsimilarity: build/newrom_generic $(TOOL_SIMILARITY)
+	$(TOOL_SIMILARITY) kernal build/newrom_generic
+	$(TOOL_SIMILARITY) basic build/newrom_generic
diff --git a/STATUS.md b/STATUS.md
new file mode 100644
index 00000000..286da229
--- /dev/null
+++ b/STATUS.md
@@ -0,0 +1,117 @@
+# New features
+
+
+Here are the features of the Open ROMs not found in the original ROMs from the 80s:
+
+* improved keyboard scanning, supports multi-key roll-over and rejection of spurious joystick input
+* joystick (port 1) can be used to move text cursor
+* uses RAM under ROM and I/O: 61436 bytes free
+* extended `LOAD` command
+    * start/end addresses are displayed, in the Final cartridge style
+    * command with just the file name tries to use the last device if it's number seems sane; otherwise uses 8
+    * secondary address over 255 is considered a start address
+* DOS wedge (direct mode only) - `@<drive_number>`, `@<command>`, `@$`, `@$<params>`, `@`
+
+NOTE: extra features and their syntax can change in the future!
+
+# Features missing
+
+
+The following ROM features are currently missing:
+
+* most BASIC commands
+* BASIC variables
+* BASIC expression parsing
+* floating point routines
+* tape support
+* RS-232 support
+* warm start (RUN/STOP + RESTORE) - NMI is not implemented at all
+* breaking Kernal routines with RUN/STOP key
+
+Features currently being worked on:
+
+* IEC support needs more testing ang bugfixing; alternative drive ROMs (JiffyDOS, DolphinDOS, etc) usually don't work with current implementation, `@$` leaves the drive led on, most likely other problems can be found
+
+# API status
+
+
+Status of the various APIs and variables from the original ROMs
+
+
+## Page 0
+
+
+TODO
+
+
+## Pages 2 & 3
+
+
+TODO
+
+
+## BASIC
+
+
+TODO
+
+
+## Kernal
+
+
+Note: only the jump table addresses are currently supported, real routine addresses are different!
+
+
+### Official Kernal routines
+
+NOTE: Even the 'DONE' routines won't support features described as missing in one of the previous chapters!
+
+<br />
+
+| Address   | Name     | Status   |  Remarks                                           |
+| --------- | :------- | :------: | :------------------------------------------------: |
+| `$FF81`   | `CINT`   | PARTIAL  | at least PAL/NTSC detection is missing             |
+| `$FF84`   | `IOINIT` | PARTIAL  | at least SID volume handling is missing            |
+| `$FF87`   | `RAMTAS` | DONE     |                                                    |
+| `$FF8A`   | `RESTOR` | PARTIAL  | CBINV, NMINV, and USRCMD missing                   |
+| `$FF8D`   | `VECTOR` | DONE     |                                                    |
+| `$FF90`   | `SETMSG` | DONE     |                                                    |
+| `$FF93`   | `SECOND` | DONE     |                                                    |
+| `$FF96`   | `TKSA`   | DONE     |                                                    |
+| `$FF99`   | `MEMTOP` | DONE     |                                                    |
+| `$FF9C`   | `MEMBOT` | DONE     |                                                    |
+| `$FF9F`   | `SCNKEY` | DONE     | could be better integrated with ROM (aliases)      |
+| `$FFA2`   | `SETTMO` | NOT DONE |                                                    |
+| `$FFA5`   | `ACPTR`  | DONE     |                                                    |
+| `$FFA8`   | `CIOUT`  | DONE     |                                                    |
+| `$FFAB`   | `UNTLK`  | DONE     |                                                    |
+| `$FFAE`   | `UNLSN`  | DONE     |                                                    |
+| `$FFB1`   | `LISTEN` | DONE     |                                                    |
+| `$FFB4`   | `TALK`   | DONE     |                                                    |
+| `$FFB7`   | `READST` | DONE     |                                                    |
+| `$FFBA`   | `SETFLS` | DONE     |                                                    |
+| `$FFBD`   | `SETNAM` | DONE     |                                                    |
+| `$FFC0`   | `OPEN`   | DONE     |                                                    |
+| `$FFC3`   | `CLOSE`  | PARTIAL  | most likely incompleete, @$ doesn't end properly   |
+| `$FFC6`   | `CHKIN`  | DONE     |                                                    |
+| `$FFC9`   | `CHKOUT` | PARTIAL  |                                                    |
+| `$FFCC`   | `CLRCHN` | DONE     |                                                    |
+| `$FFCF`   | `CHRIN`  | PARTIAL  |                                                    |
+| `$FFD2`   | `CHROUT` | PARTIAL  |                                                    |
+| `$FFD5`   | `LOAD`   | PARTIAL  | no VERIFY support yet                              |
+| `$FFD8`   | `SAVE`   | NOT DONE |                                                    |
+| `$FFDB`   | `SETTIM` | NOT DONE |                                                    |
+| `$FFDE`   | `RDTIM`  | NOT DONE |                                                    |
+| `$FFE1`   | `STOP`   | PARTIAL  | no connection with UDTIM                           |
+| `$FFE4`   | `GETIN`  | PARTIAL  | only some devices supported                        |
+| `$FFE7`   | `CLALL`  | DONE     |                                                    |
+| `$FFEA`   | `UDTIM`  | NOT DONE |                                                    |
+| `$FFED`   | `SCREEN` | DONE     |                                                    |
+| `$FFF0`   | `PLOT`   | NOT DONE |                                                    |
+| `$FFF3`   | `IOBASE` | DONE     |                                                    |
+
+<br />
+
+### Unofficial Kernal locations
+
+TODO
diff --git a/bin/REEADME.txt b/bin/REEADME.txt
new file mode 100644
index 00000000..d3a254bc
--- /dev/null
+++ b/bin/REEADME.txt
@@ -0,0 +1,14 @@
+
+Follow these rules, or bad things will happen!
+
+
+- Don't mix ROMs for different platforms - use generic BASIC with generic KERNAL, Mega65 BASIC with Mega65 KERNAL, etc.
+
+- Don't mix these ROMs with any other ROMs; the only exception is CHARGEN, this one is fully interchangeable.
+
+- Don't mix ROMs from different builds/versions (again, CHARGEN is an exception).
+
+- The generic ROM set should be compatible with any C64-compatible machine; platform-specific ROMs might not work on other platforms.
+
+
+Have fun!
diff --git a/bin/basic b/bin/basic_generic.rom
similarity index 51%
rename from bin/basic
rename to bin/basic_generic.rom
index 2de26fca..29d891b1 100644
Binary files a/bin/basic and b/bin/basic_generic.rom differ
diff --git a/bin/basic_mega65.rom b/bin/basic_mega65.rom
new file mode 100644
index 00000000..a72bf16d
Binary files /dev/null and b/bin/basic_mega65.rom differ
diff --git a/bin/basic_ultimate64.rom b/bin/basic_ultimate64.rom
new file mode 100644
index 00000000..6ed9ce5b
Binary files /dev/null and b/bin/basic_ultimate64.rom differ
diff --git a/bin/chargen.rom b/bin/chargen.rom
new file mode 100644
index 00000000..11cbd8c2
Binary files /dev/null and b/bin/chargen.rom differ
diff --git a/bin/kernal b/bin/kernal
deleted file mode 100644
index 16a9a00b..00000000
Binary files a/bin/kernal and /dev/null differ
diff --git a/bin/kernal_generic.rom b/bin/kernal_generic.rom
new file mode 100644
index 00000000..35157ebb
Binary files /dev/null and b/bin/kernal_generic.rom differ
diff --git a/bin/kernal_mega65.rom b/bin/kernal_mega65.rom
new file mode 100644
index 00000000..35157ebb
Binary files /dev/null and b/bin/kernal_mega65.rom differ
diff --git a/bin/kernal_ultimate64.rom b/bin/kernal_ultimate64.rom
new file mode 100644
index 00000000..35157ebb
Binary files /dev/null and b/bin/kernal_ultimate64.rom differ
diff --git a/c64/aliases/,aliases_error_codes.s b/c64/aliases/,aliases_error_codes.s
new file mode 100644
index 00000000..e27f5373
--- /dev/null
+++ b/c64/aliases/,aliases_error_codes.s
@@ -0,0 +1,63 @@
+
+	;; Kernal error codes - returned in the A register
+	;; Described in 'Commodore 64 Programmer's Reference Guide', page 306
+
+	.alias K_ERR_ROUTINE_TERMINATED       $00
+	.alias K_ERR_TOO_MANY_OPEN_FILES      $01
+	.alias K_ERR_FILE_ALREADY_OPEN        $02
+	.alias K_ERR_FILE_NOT_OPEN            $03
+	.alias K_ERR_FILE_NOT_FOUND           $04
+	.alias K_ERR_DEVICE_NOT_FOUND         $05
+	.alias K_ERR_FILE_NOT_INPUT           $06
+	.alias K_ERR_FILE_NOT_OUTPUT          $07
+	.alias K_ERR_FILE_NAME_MISSING        $08
+	.alias K_ERR_ILLEGAL_DEVICE_NUMBER    $09
+	.alias K_ERR_TOP_MEM_RS232            $F0
+
+	;; Kernal status codes for READST routine (IOSTATUS)
+	;; Described in 'Commodore 64 Programmer's Reference Guide', page 292
+
+	;; For IEC devices
+	.alias K_STS_TIMEOUT_WRITE            $01
+	.alias K_STS_TIMEOUT_READ             $02
+	.alias K_STS_EOI                      $40
+	.alias K_STS_DEVICE_NOT_FOUND         $80
+	;; For tape deck
+	.alias K_STS_SHORT_BLOCK              $04
+	.alias K_STS_LONG_BLOCK               $08
+	.alias K_STS_READ_ERROR               $10
+	.alias K_STS_CHECKSUM_ERROR           $20
+	.alias K_STS_END_OF_FILE              $40
+	.alias K_STS_END_OF_TAPE              $80
+
+	;; BASIC error codes, taken from http://sta.c64.org/cbm64baserr.html
+	.alias B_ERR_TOO_MANY_FILES           $01
+	.alias B_ERR_FILE_OPEN                $02
+	.alias B_ERR_FILE_NOT_OPEN            $03
+	.alias B_ERR_FILE_NOT_FOUND           $04
+	.alias B_ERR_DEVICE_NOT_PRESENT       $05
+	.alias B_ERR_NOT_INPUT_FILE           $06
+	.alias B_ERR_NOT_OUTPUT_FILE          $07
+	.alias B_ERR_MISSING_FILENAME         $08
+	.alias B_ERR_ILLEGAL_DEVICE_NUMBER    $09
+	.alias B_ERR_NEXT_WITHOUT_FOR         $0A
+	.alias B_ERR_SYNTAX                   $0B
+	.alias B_ERR_RETURN_WITHOUT_GOSUB     $0C
+	.alias B_ERR_OUT_OF_DATA              $0D
+	.alias B_ERR_ILLEGAL_QUANTITY         $0E
+	.alias B_ERR_OVERFLOW                 $0F
+	.alias B_ERR_OUT_OF_MEMORY            $10
+	.alias B_ERR_UNDEFD_STATEMENT         $11
+	.alias B_ERR_BAD_SUBSCRIPT            $12
+	.alias B_ERR_REDIMD_ARRAY             $13
+	.alias B_ERR_DIVISION_BY_ZERO         $14
+	.alias B_ERR_ILLEGAL_DIRECT           $15
+	.alias B_ERR_TYPE_MISMATCH            $16
+	.alias B_ERR_STRING_TOO_LONG          $17
+	.alias B_ERR_FILE_DATA                $18
+	.alias B_ERR_FORMULA_TOO_COMPLEX      $19
+	.alias B_ERR_CANT_CONTINUE            $1A
+	.alias B_ERR_UNDEFD_FUNCTION          $1B
+	.alias B_ERR_VERIFY                   $1C
+	.alias B_ERR_LOAD                     $1D
+	.alias B_ERR_BREAK                    $1E
diff --git a/c64/aliases/,aliases_hardware.s b/c64/aliases/,aliases_hardware.s
new file mode 100644
index 00000000..ee6ceddb
--- /dev/null
+++ b/c64/aliases/,aliases_hardware.s
@@ -0,0 +1,154 @@
+
+;;
+;; Names of hardware registers - slightly modified names from C64 Programmer's Reference Guide
+;;
+
+	;; CPU memory registers
+
+	.alias CPU_D6510      $0000
+	.alias CPU_R6510      $0001
+
+	;; VIC-II registers
+
+	.alias VIC_SP0X       $D000
+	.alias VIC_SP0Y       $D001
+	.alias VIC_SP1X       $D002
+	.alias VIC_SP1Y       $D003
+	.alias VIC_SP2X       $D004
+	.alias VIC_SP2Y       $D005
+	.alias VIC_SP3X       $D006
+	.alias VIC_SP3Y       $D007
+	.alias VIC_SP4X       $D008
+	.alias VIC_SP4Y       $D009
+	.alias VIC_SP5X       $D00A
+	.alias VIC_SP5Y       $D00B
+	.alias VIC_SP6X       $D00C
+	.alias VIC_SP6Y       $D00D
+	.alias VIC_SP7X       $D00E
+	.alias VIC_SP7Y       $D00F
+
+	.alias VIC_MSIGX      $D010
+	.alias VIC_SCROLLY    $D011
+	.alias VIC_RASTER     $D012
+	.alias VIC_LPENX      $D013
+	.alias VIC_LPENY      $D014
+	.alias VIC_SPENA      $D015
+	.alias VIC_SCROLX     $D016
+	.alias VIC_YXPAND     $D017
+	.alias VIC_YMCSB      $D018
+	.alias VIC_IRQ        $D019
+	.alias VIC_IRQMSK     $D01A
+	.alias VIC_SPBGPR     $D01B
+	.alias VIC_SPMC       $D01C
+	.alias VIC_XXPAND     $D01D
+	.alias VIC_SPSPCL     $D01E
+	.alias VIC_SPBGCL     $D01F
+
+	.alias VIC_EXTCOL     $D020
+	.alias VIC_BGCOL0     $D021
+	.alias VIC_BGCOL1     $D022
+	.alias VIC_BGCOL2     $D023
+	.alias VIC_BGCOL3     $D024
+	.alias VIC_SPMC0      $D025
+	.alias VIC_SPMC1      $D026
+	.alias VIC_SP0COL     $D027
+	.alias VIC_SP1COL     $D028
+	.alias VIC_SP2COL     $D029
+	.alias VIC_SP3COL     $D02A
+	.alias VIC_SP4COL     $D02B
+	.alias VIC_SP5COL     $D02C
+	.alias VIC_SP6COL     $D02D
+	.alias VIC_SP7COL     $D02E
+	
+	;; SID #1 registers
+
+	.alias SID1_FRELO1    $D400
+	.alias SID1_FREHI1    $D401
+	.alias SID1_PWLO1     $D402
+	.alias SID1_PWHI1     $D403
+	.alias SID1_VCREG1    $D404
+	.alias SID1_ATDCY1    $D405
+	.alias SID1_SUREL1    $D406
+
+	.alias SID1_FRELO2    $D407
+	.alias SID1_FREHI2    $D408
+	.alias SID1_PWLO2     $D409
+	.alias SID1_PWHI2     $D40A
+	.alias SID1_VCREG2    $D40B
+	.alias SID1_ATDCY2    $D40C
+	.alias SID1_SUREL2    $D40D
+
+	.alias SID1_FRELO3    $D40E
+	.alias SID1_FREHI3    $D40F
+	.alias SID1_PWLO3     $D410
+	.alias SID1_PWHI3     $D411
+	.alias SID1_VCREG3    $D412
+	.alias SID1_ATDCY3    $D413
+	.alias SID1_SUREL3    $D414
+
+	.alias SID1_CUTLO     $D415
+	.alias SID1_CUTHI     $D416
+	.alias SID1_RESON     $D417
+	.alias SID1_SIGVOL    $D418
+	.alias SID1_POTX      $D419
+	.alias SID1_POTY      $D41A
+	.alias SID1_RANDOM    $D41B
+	.alias SID1_ENV3      $D41C
+
+	;; SID #2, #3, #4 registers
+
+	.alias SID2_SIGVOL    $D438
+	.alias SID3_SIGVOL    $D458
+	.alias SID4_SIGVOL    $D478
+
+	;; CIA #1 registers
+
+	.alias CIA1_PRA       $DC00
+	.alias CIA1_PRB       $DC01
+	.alias CIA1_DDRA      $DC02
+	.alias CIA1_DDRB      $DC03
+
+	.alias CIA1_TIMALO    $DC04
+	.alias CIA1_TIMAHI    $DC05
+	.alias CIA1_TIMBLO    $DC06
+	.alias CIA1_TIMBHI    $DC07
+
+	.alias CIA1_TODTEN    $DC08
+	.alias CIA1_TODSEC    $DC09
+	.alias CIA1_TODMIN    $DC0A
+	.alias CIA1_TODHRS    $DC0B
+
+	.alias CIA1_SDR       $DC0C
+	.alias CIA1_ICR       $DC0D
+	.alias CIA1_CRA       $DC0E
+	.alias CIA1_CRB       $DC0F
+
+	;; CIA #2 registers
+
+	.alias CIA2_PRA       $DD00 ; VIC bank switching and IEC port
+	.alias CIA2_PRB       $DD01
+	.alias CIA2_DDRA      $DD02
+	.alias CIA2_DDRB      $DD03
+
+	.alias CIA2_TIMALO    $DD04
+	.alias CIA2_TIMAHI    $DD05
+	.alias CIA2_TIMBLO    $DD06
+	.alias CIA2_TIMBHI    $DD07
+
+	.alias CIA2_TODTEN    $DD08
+	.alias CIA2_TODSEC    $DD09
+	.alias CIA2_TODMIN    $DD0A
+	.alias CIA2_TODHRS    $DD0B
+
+	.alias CIA2_SDR       $DD0C
+	.alias CIA2_ICR       $DD0D
+	.alias CIA2_CRA       $DD0E
+	.alias CIA2_CRB       $DD0F
+
+	;; CIA #2 helper bits - IEC bus
+	
+	.alias BIT_CIA2_PRA_ATN_OUT $08    ; 1 - low (pulled), 0 - high (released)
+	.alias BIT_CIA2_PRA_CLK_OUT $10    ; 1 - low (pulled), 0 - high (released)
+	.alias BIT_CIA2_PRA_DAT_OUT $20    ; 1 - low (pulled), 0 - high (released)
+	.alias BIT_CIA2_PRA_CLK_IN  $40    ; 0 - low (pulled), 1 - high (released)
+	.alias BIT_CIA2_PRA_DAT_IN  $80    ; 0 - low (pulled), 1 - high (released)
diff --git a/c64/aliases/,aliases_ram_lowmem.s b/c64/aliases/,aliases_ram_lowmem.s
new file mode 100644
index 00000000..311fbf87
--- /dev/null
+++ b/c64/aliases/,aliases_ram_lowmem.s
@@ -0,0 +1,99 @@
+;;
+;; Names of ZP and low memory locations
+;; (https://www.c64-wiki.com/wiki/Zeropage)
+;;
+
+	;; $00-$01 - 6502 CPU registers are here
+
+    ;;
+	;; Page 0 - BASIC area ($02-$8F)
+    ;;
+	
+	.alias TXTTAB     $2B
+
+    ;;
+	;; Page 0 - Kernal area ($90-$FF)
+    ;;
+	
+	.alias IOSTATUS   $90
+	.alias STKEY      $91 ; Keys down clears bits. STOP - bit 7, C= - bit 6, SPACE - bit 4, CTRL - bit 2
+	
+	.alias VERCK      $93 ; 0 = LOAD, 1 = VERIVY
+	
+	.alias C3PO       $94 ; flag - is BSOUR content valid
+	.alias BSOUR      $95 ; serial bus buffered output byte
+
+	.alias LDTND      $98 ; number of entries in LAT / FAT / SAT tables
+	.alias DFLTN      $99
+	.alias DFLTO      $9A
+	
+	.alias MSGFLG     $9D ; bit 6 = error messages, bit 7 = control message
+
+	.alias TIME       $A0 ; $A0-$A2, jiffy clock
+
+	.alias IEC_TMP1   $A3 ; temporary variable for tape and IEC
+	.alias IEC_TMP2   $A4 ; temporary variable for tape and IEC
+
+	;; 2-byte location below seems to be a good place for temporary storage,
+	;; it seems used for timing during tape reads only - see:
+	;; - 'C64 Programmer's Reference Guide', page 314
+	;; - 'Compute's Mapping the Commodore 64', page 32
+	.alias CMP0       $B0 ; $B0-$B1
+	
+	.alias FNLEN      $B7 ; current file name length
+
+	.alias FNADDR     $BB ; $BB-$BC, current file name pointer
+
+	.alias STAL       $C1 ; $C1-$C2 LOAD/SAVE start address
+
+	;;
+	;; Other low memory addresses
+	;;
+    
+	.alias BUF        $200 ; $200-$250 (81 bytes), BASIC line editor input buffer
+
+	;; Kernal tables for opened files, 10 entries each
+	.alias LAT        $259 ; logical file numbers
+	.alias FAT        $263 ; device numbers
+	.alias SAT        $26D ; secondary addresses
+
+	.alias MEMSTR     $281
+	.alias MEMSIZ     $283 ; NOTE: Mapping the 64 erroniously has the hex as $282, while the DEC is correct
+
+	.alias HIBASE     $288 ; high byte of start of screen
+
+	.alias RSSTAT     $297 ; RS-232 status
+
+	.alias PALNTSC    $2A6 ; 0 = NTSC, 1 = PAL
+	
+	
+	;; Registers for SYS call
+	.alias SAREG      $30C
+	.alias SXREG      $30D
+	.alias SYREG      $30E
+	.alias SPREG      $30F
+
+	.alias USRPOK     $310 ; JMP instruction
+	.alias USRADD     $311 ; $311 - $312
+	
+	;; Kernal vectors - interrupts
+	.alias CINV       $314
+	.alias CBINV      $316 
+	.alias NMINV      $318
+	
+	;; Kernal vectors - routines
+	.alias IOPEN      $31A
+	.alias ICLOSE     $31C
+	.alias ICHKIN     $31E
+	.alias ICKOUT     $320
+	.alias ICLRCH     $322
+	.alias IBASIN     $324
+	.alias IBSOUT     $326
+	.alias ISTOP      $328
+	.alias IGETIN     $32A
+	.alias ICLALL     $32C
+	.alias USRCMD     $32E
+	.alias ILOAD      $330
+	.alias ISAVE      $331
+
+	.alias TBUFFR     $33C ; $33C-$3FB, tape buffer	
diff --git a/c64/aliases/,aliases_rom_basic.s b/c64/aliases/,aliases_rom_basic.s
new file mode 100644
index 00000000..e69de29b
diff --git a/c64/aliases/,aliases_rom_kernal.s b/c64/aliases/,aliases_rom_kernal.s
new file mode 100644
index 00000000..91c601d9
--- /dev/null
+++ b/c64/aliases/,aliases_rom_kernal.s
@@ -0,0 +1,41 @@
+
+	;; Kernal jump table
+	.alias JCINT     $FF81
+	.alias JIOINIT   $FF84
+	.alias JRAMTAS   $FF87
+	.alias JRESTOR   $FF8A
+	.alias JVECTOR   $FF8D
+	.alias JSETMSG   $FF90
+	.alias JSECOND   $FF93
+	.alias JTKSA     $FF96
+	.alias JMEMTOP   $FF99
+	.alias JMEMBOT   $FF9C
+	.alias JSCNKEY   $FF9F
+	.alias JSETTMO   $FFA2
+	.alias JACPTR    $FFA5
+	.alias JCIOUT    $FFA8
+	.alias JUNTLK    $FFAB
+	.alias JUNLSN    $FFAE
+	.alias JLISTEN   $FFB1
+	.alias JTALK     $FFB4
+	.alias JREADST   $FFB7
+	.alias JSETFLS   $FFBA
+	.alias JSETNAM   $FFBD
+	.alias JOPEN     $FFC0
+	.alias JCLOSE    $FFC3
+	.alias JCHKIN    $FFC6
+	.alias JCKOUT    $FFC9
+	.alias JCLRCHN   $FFCC
+	.alias JCHRIN    $FFCF
+	.alias JCHROUT   $FFD2
+	.alias JLOAD     $FFD5
+	.alias JSAVE     $FFD8
+	.alias JSETTIM   $FFDB
+	.alias JRDTIM    $FFDE
+	.alias JSTOP     $FFE1
+	.alias JGETIN    $FFE4
+	.alias JCLALL    $FFE7
+	.alias JUDTIM    $FFEA
+	.alias JSCREEN   $FFED
+	.alias JPLOT     $FFF0
+	.alias JIOBASE   $FFF3
diff --git a/c64/basic/,aliases.s b/c64/basic/,aliases.s
index 712e7c35..e54dd5a9 100644
--- a/c64/basic/,aliases.s
+++ b/c64/basic/,aliases.s
@@ -52,22 +52,13 @@
 	.alias memmove_dst $6b
 	.alias memmove_size $6d	
 	
-	.alias TXTTAB $2B
-	.alias IOSTATUS $90
-	; Keys down clears bits. STOP=bit 7, C= bit 6, SPACE bit 4, CTRL bit 2
-	.alias BUCKYSTATUS $91
-	.alias load_or_verify_flag $93
 	.alias current_file_num $98
-	.alias input_device_number $99
-	; bit 6 = error messages, bit 7 = control messages
-	.alias kernal_message_control_flags $9d
-	.alias jiffy_clock_24bits $a0
 	.alias cassette_buffer_bytes_used $A6
 	.alias load_or_scroll_temp_pointer $AC
 	;; We also use the following for temp colour pointer when scrolling
 	.alias load_save_verify_end_address $AE
+
 	.alias cassette_buffer_ptr $B2
-	.alias current_filename_length $B7
 	.alias current_logical_filenum $B8
 	.alias current_secondary_address $B9
 	.alias current_device_number $BA
@@ -100,15 +91,12 @@
 	.alias rs232_rx_buffer_ptr $F7
 	.alias rs232_tx_buffer_ptr $F9
 
-	.alias basic_input_buffer $0200
-	
+	.alias basic_input_buffer BUF
+		
 	; "Compute's Mapping the 64" book
 	.alias keyboard_buffer $0277
-	.alias MEMSTR $0281
-	.alias MEMSIZ $0283 	; NOTE: Mapping the 64 erroniously has the hex as $282, while the DEC is correct
 	.alias text_colour $0286 ; p55
 	.alias colour_under_cursor $0287 ; p56
-	.alias HIBASE $0288     ; p56 (high byte of start of screen)
 	.alias key_buffer_size $0289 ; p57
 
 	;; 0 = cursor keys, insert, delete and space repeat, but nothing else
@@ -124,14 +112,6 @@
 	.alias keyboard_decoding_ptr $028F
 	.alias enable_case_switch $0291
 	.alias screen_scroll_disable $0292
-	.alias pal_or_ntsc $02A6
-
-	;; Registers for SYS call
-	.alias sys_reg_a $30c
-	.alias sys_reg_x $30d
-	.alias sys_reg_y $30e
-	.alias sys_reg_p $30f
-	.alias sys_jmp   $310
 
 	;; BASIC uses some extra bytes for memory access under ROMs located at $2A7 onwards
 	;; IRQs are disabled when doing such accesses, and a default NMI handler only increments
@@ -144,4 +124,3 @@
 	.alias poke_under_roms tiny_nmi_handler+poke_under_roms_routine-tiny_nmi_handler_routine
 	.alias memmap_allram tiny_nmi_handler+memmap_allram_routine-tiny_nmi_handler_routine
 	.alias memmap_normal tiny_nmi_handler+memmap_normal_routine-tiny_nmi_handler_routine
-	
diff --git a/c64/basic/,target_generic/,hooks_generic.s b/c64/basic/,target_generic/,hooks_generic.s
new file mode 100644
index 00000000..186b29d0
--- /dev/null
+++ b/c64/basic/,target_generic/,hooks_generic.s
@@ -0,0 +1,9 @@
+
+;; Target-specific hooks
+
+
+.macro TARGET_HOOK_BANNER
+
+	.byte $05, "  OPEN ROMS, ", $00
+
+.macend
diff --git a/c64/basic/,target_mega65/,hooks_mega65.s b/c64/basic/,target_mega65/,hooks_mega65.s
new file mode 100644
index 00000000..97c859e5
--- /dev/null
+++ b/c64/basic/,target_mega65/,hooks_mega65.s
@@ -0,0 +1,41 @@
+
+;; Target-specific hooks
+
+
+.macro TARGET_HOOK_BANNER
+
+	;; New banner from Retrofan
+	.byte $9a, $12, $20, $20, $7f, $a9, $20, $20, $1f, $20, $9a, $20, $20, $20
+	.byte $20, $1f, $20, $9a, $a9, $20, $20, $20, $92, $a1, $1f, $12, $20, $9a, $a9, $20
+	.byte $20, $20, $7f, $1f, $20, $20, $9a, $a3, $a3, $a3, $a3, $a3, $a3, $a3, $1f, $20
+	.byte $20, $20, $20, $05, $92, $4d, $45, $47, $41, $9a, $12, $20, $20, $20, $20, $20
+	.byte $20, $1f, $20, $9a, $20, $20, $92, $a2, $bb, $1f, $12, $20, $9a, $20, $20, $92
+	.byte $ac, $a2, $a2, $1f, $12, $20, $9a, $20, $20, $1f, $20, $9a, $20, $20, $1f, $20
+	.byte $20, $1e, $a3, $a3, $a3, $a3, $a3, $a3, $1f, $20, $20, $20, $20, $05, $92, $42
+	.byte $41, $53, $49, $43, $9a, $12, $20, $20, $92, $7f, $a9, $12, $20, $20, $1f, $20
+	.byte $9a, $20, $20, $a2, $92, $be, $1f, $12, $20, $9a, $20, $20, $92, $bc, $12, $20
+	.byte $20, $1f, $20, $9a, $20, $20, $20, $20, $20, $1f, $20, $20, $9e, $a3, $a3, $a3
+	.byte $a3, $a3, $1f, $20, $20, $20, $20, $05, $92, $2d, $2d, $2d, $2d, $2d, $2d, $9a
+	.byte $12, $20, $20, $1f, $20, $20, $9a, $20, $20, $1f, $20, $9a, $20, $20, $20, $20
+	.byte $1f, $20, $9a, $20, $20, $20, $20, $20, $1f, $20, $9a, $20, $20, $1f, $20, $9a
+	.byte $20, $20, $1f, $20, $20, $96, $a3, $a3, $a3, $a3, $1f
+	.byte $92, $0D, $0D, $05, $00
+
+	;; Original Deft-supplied banner
+	;; .byte $9A,$12,$A3,$A3,$A3,$A3,$A3,$A3,$DF,$9B,$92,$20,$05,$12,$A0,$A0
+	;; .byte $DF,$9B,$92,$20,$05,$12,$A0,$A0,$DF,$9B,$92,$20,$05,$12,$A0,$A0
+	;; .byte $DF,$9B,$92,$20,$05,$12,$A0,$A0,$DF,$9A,$92,$20,$05,$20,$20,$20
+	;; .byte $4D,$20,$45,$20,$47,$20,$41,$0D,$99,$12,$A3,$A3,$A3,$A3,$A3,$A3
+	;; .byte $A3,$DF,$92,$7F,$12,$CD,$CD,$DF,$92,$7F,$12,$DF,$05,$92,$20,$20
+	;; .byte $99,$7F,$12,$DF,$05,$92,$20,$20,$99,$7F,$12,$DF,$92,$7F,$12,$DF
+	;; .byte $05,$92,$20,$20,$99,$42,$20,$41,$20,$53,$20,$49,$20,$43,$0D,$9E
+	;; .byte $12,$A3,$A3,$A3,$A3,$A3,$A3,$A3,$A3,$DF,$9B,$92,$7F,$12,$DF,$92
+	;; .byte $7F,$12,$DF,$92,$7F,$12,$CD,$05,$92,$20,$20,$9B,$7F,$12,$CD,$92
+	;; .byte $7F,$12,$DF,$92,$7F,$12,$CD,$92,$7F,$12,$DF,$9A,$92,$20,$05,$20
+	;; .byte $9A,$2D,$2D,$2D,$2D,$2D,$2D,$2D,$0D,$96,$12,$A3,$A3,$A3,$A3,$A3
+	;; .byte $A3,$A3,$A3,$A3,$DF,$9A,$92,$7F,$12,$DF,$92,$7F,$9B,$20,$9A,$7F
+	;; .byte $12,$A0,$A0,$9B,$92,$20,$9A,$7F,$12,$A0,$A0,$9B,$92,$20,$9A,$7F
+	;; .byte $12,$DF,$92,$7F,$9B,$20,$9A,$20,$9B,"0.2.0.0",$0D
+	;; .byte $0D,$05,$92,$00
+
+.macend
diff --git a/c64/basic/,target_ultimate64/,hooks_ultimate64.s b/c64/basic/,target_ultimate64/,hooks_ultimate64.s
new file mode 100644
index 00000000..519d07e9
--- /dev/null
+++ b/c64/basic/,target_ultimate64/,hooks_ultimate64.s
@@ -0,0 +1,9 @@
+
+;; Target-specific hooks
+
+
+.macro TARGET_HOOK_BANNER
+
+	.byte $05, "  OPEN ROMS FOR ULTIMATE 64", $0D, $0D, "  ", $00
+
+.macend
diff --git a/c64/basic/ab1e.print_string.s b/c64/basic/ab1e.print_string.s
index 9ca8a586..83f8d366 100644
--- a/c64/basic/ab1e.print_string.s
+++ b/c64/basic/ab1e.print_string.s
@@ -20,7 +20,7 @@ print_string_loop:
 	lda (temp_string_ptr),y
 	beq print_string_end
 
-	jsr $FFD2 		; KERNAL CHROUT
+	jsr via_IBSOUT
 
 	txa
 	tay
diff --git a/c64/basic/basic_cold_start.s b/c64/basic/basic_cold_start.s
index 187c828e..325bd1ed 100644
--- a/c64/basic/basic_cold_start.s
+++ b/c64/basic/basic_cold_start.s
@@ -15,41 +15,7 @@ basic_cold_start:
 ; Used 217 bytes
 startup_banner:
 
-	;; New banner from Retrofan
-	.byte $9a, $12, $20, $20, $7f, $a9, $20, $20, $1f, $20, $9a, $20, $20, $20
-	.byte $20, $1f, $20, $9a, $a9, $20, $20, $20, $92, $a1, $1f, $12, $20, $9a, $a9, $20
-	.byte $20, $20, $7f, $1f, $20, $20, $9a, $a3, $a3, $a3, $a3, $a3, $a3, $a3, $1f, $20
-	.byte $20, $20, $20, $05, $92, $4d, $45, $47, $41, $9a, $12, $20, $20, $20, $20, $20
-	.byte $20, $1f, $20, $9a, $20, $20, $92, $a2, $bb, $1f, $12, $20, $9a, $20, $20, $92
-	.byte $ac, $a2, $a2, $1f, $12, $20, $9a, $20, $20, $1f, $20, $9a, $20, $20, $1f, $20
-	.byte $20, $1e, $a3, $a3, $a3, $a3, $a3, $a3, $1f, $20, $20, $20, $20, $05, $92, $42
-	.byte $41, $53, $49, $43, $9a, $12, $20, $20, $92, $7f, $a9, $12, $20, $20, $1f, $20
-	.byte $9a, $20, $20, $a2, $92, $be, $1f, $12, $20, $9a, $20, $20, $92, $bc, $12, $20
-	.byte $20, $1f, $20, $9a, $20, $20, $20, $20, $20, $1f, $20, $20, $9e, $a3, $a3, $a3
-	.byte $a3, $a3, $1f, $20, $20, $20, $20, $05, $92, $2d, $2d, $2d, $2d, $2d, $2d, $9a
-	.byte $12, $20, $20, $1f, $20, $20, $9a, $20, $20, $1f, $20, $9a, $20, $20, $20, $20
-	.byte $1f, $20, $9a, $20, $20, $20, $20, $20, $1f, $20, $9a, $20, $20, $1f, $20, $9a
-	.byte $20, $20, $1f, $20, $20, $96, $a3, $a3, $a3, $a3, $1f
-	.byte $92, $0D, $0D, $05
-
-	.byte $00
-	
-	;; Original Deft-supplied banner
-	;; .byte $9A,$12,$A3,$A3,$A3,$A3,$A3,$A3,$DF,$9B,$92,$20,$05,$12,$A0,$A0
-	;; .byte $DF,$9B,$92,$20,$05,$12,$A0,$A0,$DF,$9B,$92,$20,$05,$12,$A0,$A0
-	;; .byte $DF,$9B,$92,$20,$05,$12,$A0,$A0,$DF,$9A,$92,$20,$05,$20,$20,$20
-	;; .byte $4D,$20,$45,$20,$47,$20,$41,$0D,$99,$12,$A3,$A3,$A3,$A3,$A3,$A3
-	;; .byte $A3,$DF,$92,$7F,$12,$CD,$CD,$DF,$92,$7F,$12,$DF,$05,$92,$20,$20
-	;; .byte $99,$7F,$12,$DF,$05,$92,$20,$20,$99,$7F,$12,$DF,$92,$7F,$12,$DF
-	;; .byte $05,$92,$20,$20,$99,$42,$20,$41,$20,$53,$20,$49,$20,$43,$0D,$9E
-	;; .byte $12,$A3,$A3,$A3,$A3,$A3,$A3,$A3,$A3,$DF,$9B,$92,$7F,$12,$DF,$92
-	;; .byte $7F,$12,$DF,$92,$7F,$12,$CD,$05,$92,$20,$20,$9B,$7F,$12,$CD,$92
-	;; .byte $7F,$12,$DF,$92,$7F,$12,$CD,$92,$7F,$12,$DF,$9A,$92,$20,$05,$20
-	;; .byte $9A,$2D,$2D,$2D,$2D,$2D,$2D,$2D,$0D,$96,$12,$A3,$A3,$A3,$A3,$A3
-	;; .byte $A3,$A3,$A3,$A3,$DF,$9A,$92,$7F,$12,$DF,$92,$7F,$9B,$20,$9A,$7F
-	;; .byte $12,$A0,$A0,$9B,$92,$20,$9A,$7F,$12,$A0,$A0,$9B,$92,$20,$9A,$7F
-	;; .byte $12,$DF,$92,$7F,$9B,$20,$9A,$20,$9B,"0.2.0.0",$0D
-	;; .byte $0D,$05,$92,$00
+	`TARGET_HOOK_BANNER
 
 	;; Work out free bytes, and display
 	jsr basic_do_new
@@ -63,7 +29,7 @@ startup_banner:
 	jsr print_integer	
 
 	lda #$20
-	jsr $ffd2
+	jsr via_IBSOUT
 	
 	;; Print the rest of the start up message
 	ldx #34
diff --git a/c64/basic/basic_do_error.s b/c64/basic/basic_do_error.s
index 584bfe19..92d7e46d 100644
--- a/c64/basic/basic_do_error.s
+++ b/c64/basic/basic_do_error.s
@@ -7,9 +7,9 @@ basic_do_error:
 
 	;; Print ? at start
 	lda #$0d
-	jsr $ffd2
+	jsr via_IBSOUT
 	lda #$3f
-	jsr $ffd2
+	jsr via_IBSOUT
 
 	;; Print main part of error message
 	pla
@@ -18,7 +18,7 @@ basic_do_error:
 
 	;; Print ERROR at end
 	lda #$20
-	jsr $ffd2
+	jsr via_IBSOUT
 	ldx #33
 	jsr print_packed_message
 
@@ -27,9 +27,9 @@ basic_do_error:
 	;; XXX print line number if not in direct mode
 
 	lda #$0d
-	jsr $ffd2
+	jsr via_IBSOUT
 	lda #$0d
-	jsr $ffd2
+	jsr via_IBSOUT
 
 	;; Reset stack, and go back to main loop
 	ldx #$fe
diff --git a/c64/basic/basic_execute_line.s b/c64/basic/basic_execute_line.s
index a7689e51..5ea0aafb 100644
--- a/c64/basic/basic_execute_line.s
+++ b/c64/basic/basic_execute_line.s
@@ -29,7 +29,7 @@ no_space_to_skip:
 basic_execute_statement:
 
 	;; Check for RUN/STOP
-	lda BUCKYSTATUS
+	lda STKEY
 	bpl basic_do_break
 	
 	;; Skip over any white space and :
@@ -80,9 +80,9 @@ basic_execute_statement:
 	;; Now consume the character
 	jsr basic_consume_character
 	
-	rts	
+	rts
 
-not_a_token:	
+not_a_token:
 	;; Space, which we can also just ignore
 	cmp #$20
 	beq basic_skip_char
@@ -93,11 +93,28 @@ not_a_token:
 	cmp #$3a
 	beq basic_skip_char
 	
+;; START wedge support
+	
+	;; Are we in direct mode?
+	;; DOS Wedge is a hacky solution (inelegant, but convenient),
+	;; BASIC programmers should implement communication with drives
+	;; the standard way, handling channels properly. Besides,
+	;; current implementation does not support characters under ROM
+	ldx basic_current_line_number+1
+	cpx #$ff
+	bne +
+	;; We are in direct mode, allow wedge to handle '@' sign
+	;; XXX Maybe it should be allowed only as the first command?
+	cmp #$40
+	bne +
+	jsr basic_consume_character
+	jmp wedge_dos
+*
+;; END wedge support
+
 	;; If all else fails, it's a syntax error
 	jmp do_SYNTAX_error
 
-	jmp basic_main_loop
-
 basic_skip_char:
 	jsr basic_consume_character
 	jmp basic_execute_statement
diff --git a/c64/basic/basic_main_loop.s b/c64/basic/basic_main_loop.s
index 233bd60c..2d7afdd6 100644
--- a/c64/basic/basic_main_loop.s
+++ b/c64/basic/basic_main_loop.s
@@ -52,7 +52,7 @@ rsl_l1:	lda $0200,x
 *	
 	;; Do printing of the new line
 	lda #$0d
-	jsr $ffd2
+	jsr via_IBSOUT
 
 	;; Ignore empty lines
 	lda tokenise_work1
diff --git a/c64/basic/cmd_break.s b/c64/basic/cmd_break.s
index 38c7bd3d..31194132 100644
--- a/c64/basic/cmd_break.s
+++ b/c64/basic/cmd_break.s
@@ -17,7 +17,7 @@ basic_do_break:
 	
 *
 	lda #$0d
-	jsr $ffd2
+	jsr via_IBSOUT
 cmd_end:
 	jmp basic_main_loop
 	
diff --git a/c64/basic/cmd_list.s b/c64/basic/cmd_list.s
index ba02f675..a1be1724 100644
--- a/c64/basic/cmd_list.s
+++ b/c64/basic/cmd_list.s
@@ -22,10 +22,16 @@ list_loop:
 	jmp basic_main_loop
 
 list_more_lines:
-	lda BUCKYSTATUS
+	lda STKEY
 	bmi +
 	jmp basic_do_break
 *
+	jsr list_single_line
+	;; Now link to the next line
+	jsr basic_find_next_line
+	jmp list_loop
+
+list_single_line: ; entry point needed by DOS wedge
 	;; Print line number
 	ldy #3
 	jsr peek_under_roms
@@ -36,7 +42,7 @@ list_more_lines:
 	pla
 	jsr print_integer
 	lda #$20
-	jsr $ffd2
+	jsr via_IBSOUT
 
 	;; Iterate through printing out the line
 	;; contents
@@ -105,19 +111,16 @@ list_not_rem:
 	bne list_print_loop
 
 list_is_literal:
-	jsr $ffd2
+	jsr via_IBSOUT
 	iny
 	bne list_print_loop
 	
 list_end_of_line:
 	;; Clear reverse flag
 	lda #$92
-	jsr $ffd2
+	jsr via_IBSOUT
 	;; Print end of line
 	lda #$0d
-	jsr $ffd2
+	jsr via_IBSOUT
+	rts
 
-	;; Now link to the next line
-	jsr basic_find_next_line
-	jmp list_loop
-	
diff --git a/c64/basic/cmd_load.s b/c64/basic/cmd_load.s
index 000743fd..dc900c54 100644
--- a/c64/basic/cmd_load.s
+++ b/c64/basic/cmd_load.s
@@ -11,9 +11,18 @@ cmd_load:
 	;; middle of a program. For safety, we do.
 	jsr basic_do_clr
 	
+	;; Setup Kernal to print control messages or not
+	lda #$80 ; display control messages and omit error messages
+	ldx basic_current_line_number+1
+	cpx #$FF
+	beq +
+	lda #$00 ; direct mode - don't display anything
+*
+	jsr JSETMSG
+
 	;; Set filename and length
 	lda #$00
-	sta current_filename_length
+	sta FNLEN
 
 	;; Without tape support, LOAD must have a filename
 	;; (This also skips any leading spaces)
@@ -34,7 +43,7 @@ cmd_load:
 	
 	;; Now search for end of line or closing quote
 	;; so that we know the length of the filename
-getting_filename:	
+getting_filename:
 	jsr basic_fetch_and_consume_character
 	cmp #$22
 	beq got_filename
@@ -44,19 +53,52 @@ getting_filename:
 
 	jmp got_filename
 *
-	inc current_filename_length
+	inc FNLEN
 	jmp getting_filename
 	
-got_filename:	
+got_filename:
 
-	;; Try to load an IEC file
-	lda #0			; use supplied load address, not the one from the file
+	;; Now fetch the file number, start from the default one
+	jsr select_device
+	stx current_device_number
+	jsr injest_comma
+	bcs got_devicenumber
+
+	jsr basic_parse_line_number
+	lda basic_line_number+1
+	bne do_ILLEGAL_QUANTITY_error
+	lda basic_line_number+0
+	sta current_device_number
+
+got_devicenumber:
+
+	;; Now fetch the secondary address
+	lda #$00
 	sta current_secondary_address
-	lda #$00 		; LOAD not verify
-	ldx #<$0801		; LOAD address = $0801
+	jsr injest_comma
+	bcs got_secondaryaddress
+	jsr basic_parse_line_number
+	lda basic_line_number+1
+	bne +
+	lda basic_line_number+0
+	sta current_secondary_address
+	jmp got_secondaryaddress
+*
+	;; Second parameter is above 255, this can't be a secondary address
+	;; Use it as load address instead
+	;; XXX temporary syntax, it would be better to use something
+	;; XXX like 'LOAD"FILE",8 TO 49152'
+	ldx basic_line_number+0
+	ldy basic_line_number+1
+	bne got_loadaddress
+
+got_secondaryaddress:
+	ldx #<$0801
 	ldy #>$0801
 
-	jsr $ffd5
+got_loadaddress:
+	lda #$00 		; LOAD not verify
+	jsr via_ILOAD
 	bcc +
 
 	;; A = KERNAL error code, which also almost match
diff --git a/c64/basic/cmd_new.s b/c64/basic/cmd_new.s
index ce355946..9d5f9d94 100644
--- a/c64/basic/cmd_new.s
+++ b/c64/basic/cmd_new.s
@@ -41,7 +41,7 @@ basic_do_new:
 	;; (same story), expression value cache?
 	
 	sec			; Read, not write value
-	jsr $ff99 		; KERNAL MEMTOP routine
+	jsr JMEMTOP
 	cpx #$80
 	beq +
 	lda #>$f7ff
diff --git a/c64/basic/cmd_sys.s b/c64/basic/cmd_sys.s
index 86830bd0..2328a0a4 100644
--- a/c64/basic/cmd_sys.s
+++ b/c64/basic/cmd_sys.s
@@ -10,22 +10,22 @@ cmd_sys:
 	jsr basic_parse_line_number
 
 	;; setup call
-	lda #$4c 		;JMP
-	sta sys_jmp
+	lda #$4C ;JMP
+	sta USRPOK
 	lda basic_line_number+0
-	sta sys_jmp+1
+	sta USRADD+0
 	lda basic_line_number+1
-	sta sys_jmp+2
+	sta USRADD+1
 	
 	;; Setup the register values
-	lda sys_reg_p
+	lda SPREG
 	pha
-	ldy sys_reg_y
-	ldx sys_reg_x
-	lda sys_reg_a
+	ldy SYREG
+	ldx SXREG
+	lda SAREG
 	plp
 
 	;; Call the routine.
-	jsr sys_jmp
+	jsr USRPOK
 	
 	jmp basic_execute_statement
diff --git a/c64/basic/injest_comma.s b/c64/basic/injest_comma.s
new file mode 100644
index 00000000..43be5113
--- /dev/null
+++ b/c64/basic/injest_comma.s
@@ -0,0 +1,20 @@
+
+;; Consummes a comma in a BASIC code, C set for no coma found
+
+injest_comma:
+
+	jsr basic_fetch_and_consume_character
+	cmp #$2C ; comma character
+	beq injest_comma_found
+	cmp #$20
+	beq injest_comma ; space, can always be skipped
+	
+	;; not found
+	jsr basic_unconsume_character
+	sec
+	rts
+
+injest_comma_found:
+	clc
+	rts
+
diff --git a/c64/basic/packed_messages.s b/c64/basic/packed_messages.s
deleted file mode 100644
index 2747aeda..00000000
--- a/c64/basic/packed_messages.s
+++ /dev/null
@@ -1,126 +0,0 @@
-packed_message_chars:
-	.byte $45 ; 'E'  = $1 (nybl)
-	.byte $54 ; 'T'  = $2 (nybl)
-	.byte $4F ; 'O'  = $3 (nybl)
-	.byte $4E ; 'N'  = $4 (nybl)
-	.byte $49 ; 'I'  = $5 (nybl)
-	.byte $52 ; 'R'  = $6 (nybl)
-	.byte $41 ; 'A'  = $7 (nybl)
-	.byte $4C ; 'L'  = $8 (nybl)
-	.byte $53 ; 'S'  = $9 (nybl)
-	.byte $44 ; 'D'  = $a (nybl)
-	.byte $46 ; 'F'  = $b (nybl)
-	.byte $55 ; 'U'  = $c (nybl)
-	.byte $50 ; 'P'  = $d (nybl)
-	.byte $4D ; 'M'  = $e (nybl)
-	.byte $43 ; 'C'  = $F1 / $xF $43
-	.byte $47 ; 'G'  = $F2 / $xF $47
-	.byte $59 ; 'Y'  = $F3 / $xF $59
-	.byte $56 ; 'V'  = $F4 / $xF $56
-	.byte $42 ; 'B'  = $F5 / $xF $42
-	.byte $48 ; 'H'  = $F6 / $xF $48
-	.byte $58 ; 'X'  = $F7 / $xF $58
-	.byte $57 ; 'W'  = $F8 / $xF $57
-	.byte $24 ; '$'  = $F9 / $xF $24
-	.byte $27 ; '''  = $Fa / $xF $27
-	.byte $0D ; '
'  = $Fb / $xF $0D
-	.byte $51 ; 'Q'  = $Fc / $xF $51
-	.byte $2E ; '.'  = $Fd / $xF $2E
-	.byte $23 ; '#'  = $FE/F + $23
-	.byte $4B ; 'K'  = $FE/F + $4B
-	.byte $28 ; '('  = $FE/F + $28
-	.byte $5A ; 'Z'  = $FE/F + $5A
-	.byte $2B ; '+'  = $FE/F + $2B
-	.byte $2D ; '-'  = $FE/F + $2D
-	.byte $2A ; '*'  = $FE/F + $2A
-	.byte $2F ; '/'  = $FE/F + $2F
-	.byte $5E ; '^'  = $FE/F + $5E
-	.byte $3E ; '>'  = $FE/F + $3E
-	.byte $3D ; '='  = $FE/F + $3D
-	.byte $3C ; '<'  = $FE/F + $3C
-packed_message_tokens:
-	.byte $00,$01,$02,$ff,$03,$04,$ff,$03
-	.byte $05,$04,$ff,$03,$05,$06,$ff,$07
-	.byte $05,$08,$ff,$05,$09,$03,$ff,$05
-	.byte $0a,$03,$ff,$0b,$0c,$ff,$0d,$07
-	.byte $0e,$ff,$0f,$10,$11,$ff,$12,$ff
-	.byte $13,$10,$14,$ff,$15,$16,$17,$ff
-	.byte $0d,$18,$ff,$19,$ff,$15,$16,$1a
-	.byte $ff,$1b,$1c,$ff,$1d,$1e,$ff,$1f
-	.byte $20,$ff,$21,$22,$23,$ff,$0d,$24
-	.byte $ff,$25,$26,$ff,$27,$00,$28,$ff
-	.byte $03,$17,$ff,$29,$00,$2a,$ff,$2b
-	.byte $2c,$ff,$1b,$2d,$ff,$2e,$ff,$2f
-	.byte $ff,$30,$ff,$31,$ff,$32,$ff,$33
-	.byte $ff,$34,$ff,$35,$36,$ff,$1a,$37
-	.byte $ff
-	.byte $05
-	.byte $38
-	.byte $ff
-packed_message_words:
-	.byte $23,$30,$e7,$4f,$59,$00,$b5,$81
-	.byte $90,$b5,$81,$00,$3d,$14,$00,$43
-	.byte $20,$b3,$c4,$a0,$a1,$f4,$5f,$43
-	.byte $10,$d6,$19,$14,$20,$54,$dc,$20
-	.byte $3c,$2d,$c2,$00,$e5,$99,$54,$f2
-	.byte $00,$b5,$81,$47,$e1,$00,$58,$81
-	.byte $f2,$78,$00,$4c,$ef,$42,$16,$00
-	.byte $41,$f7,$20,$f8,$52,$f6,$3c,$20
-	.byte $b3,$60,$9f,$59,$42,$7f,$58,$00
-	.byte $61,$2c,$64,$00,$f2,$39,$cf,$42
-	.byte $00,$3c,$20,$3b,$00,$a7,$27,$00
-	.byte $fc,$c7,$42,$52,$f3,$00,$3f,$56
-	.byte $16,$b8,$3f,$57,$00,$e1,$e3,$6f
-	.byte $59,$00,$c4,$a1,$bf,$27,$a0,$92
-	.byte $72,$1e,$14,$20,$f5,$7a,$00,$9c
-	.byte $f5,$9f,$43,$65,$d2,$00,$61,$a5
-	.byte $ef,$27,$a0,$76,$67,$f3,$00,$a5
-	.byte $f4,$59,$53,$40,$f5,$f3,$00,$ff
-	.byte $5a,$16,$30,$a5,$61,$f1,$20,$2f
-	.byte $59,$d1,$00,$e5,$9e,$72,$f1,$f6
-	.byte $00,$92,$65,$4f,$47,$00,$83,$4f
-	.byte $47,$00,$b3,$6e,$c8,$70,$f1,$3e
-	.byte $d8,$1f,$58,$00,$f1,$74,$fa,$20
-	.byte $f1,$34,$25,$4c,$10,$bc,$4f,$43
-	.byte $25,$34,$00,$f4,$16,$5b,$f3,$00
-	.byte $83,$7a,$00,$61,$7a,$f3,$fd,$fb
-	.byte $00,$83,$7a,$54,$f2,$00,$f4,$16
-	.byte $5b,$f3,$54,$f2,$00,$97,$f4,$54
-	.byte $f2,$00,$16,$63,$60,$f5,$f3,$21
-	.byte $90,$b6,$11,$fd,$fb,$fb,$00,$f1
-	.byte $36,$6c,$d2,$00,$5e,$d8,$1e,$14
-	.byte $21
-	.byte $a0
-packed_keywords:
-	.byte $14,$a0,$b3,$60,$41,$f7,$20,$a7
-	.byte $27,$00,$54,$dc,$2f,$23,$00,$54
-	.byte $dc,$20,$a5,$e0,$61,$7a,$00,$81
-	.byte $20,$f2,$32,$30,$6c,$40,$5b,$00
-	.byte $61,$92,$36,$10,$f2,$39,$cf,$42
-	.byte $00,$61,$2c,$64,$00,$61,$e0,$92
-	.byte $3d,$00,$34,$00,$f8,$75,$20,$83
-	.byte $7a,$00,$97,$f4,$10,$f4,$16,$5b
-	.byte $f3,$00,$a1,$b0,$d3,$ff,$4b,$10
-	.byte $d6,$54,$2f,$23,$00,$d6,$54,$20
-	.byte $f1,$34,$20,$85,$92,$00,$f1,$86
-	.byte $00,$f1,$ea,$00,$9f,$59,$90,$3d
-	.byte $14,$00,$f1,$83,$91,$00,$f2,$12
-	.byte $00,$41,$f8,$00,$27,$f5,$fe,$28
-	.byte $23,$00,$b4,$00,$9d,$f1,$fe,$28
-	.byte $2f,$48,$14,$00,$43,$20,$92,$1d
-	.byte $00,$fe,$2b,$fe,$2d,$fe,$2a,$fe
-	.byte $2f,$fe,$5e,$74,$a0,$36,$00,$fe
-	.byte $3e,$fe,$3d,$fe,$3c,$9f,$47,$40
-	.byte $54,$20,$7f,$42,$90,$c9,$60,$b6
-	.byte $10,$d3,$90,$9f,$51,$60,$64,$a0
-	.byte $83,$f2,$00,$1f,$58,$d0,$f1,$39
-	.byte $00,$95,$40,$27,$40,$72,$40,$d1
-	.byte $1f,$4b,$00,$81,$40,$92,$6f,$24
-	.byte $00,$f4,$78,$00,$79,$f1,$00,$f1
-	.byte $f6,$6f,$24,$00,$81,$b2,$f9,$00
-	.byte $65,$f2,$f6,$2f,$24,$00,$e5,$af
-	.byte $24
-	.byte $00
-	.byte $f2
-	.byte $30
-	.alias packed_keyword_table_len $DC
diff --git a/c64/basic/print_integer.s b/c64/basic/print_integer.s
index 739f8b8b..7e897243 100644
--- a/c64/basic/print_integer.s
+++ b/c64/basic/print_integer.s
@@ -58,7 +58,7 @@ hi_loop:
 	pha
 	ldx #4
 	clc
-hi_add_loop:	
+hi_add_loop:
 	lda $0100,x
 	adc number_table_hi,y
 	sta $0100,x
@@ -115,7 +115,7 @@ found_start_of_number:
 	;; Print digits
 *	lda $0100,y
 	ora #$30
-	jsr $ffd2
+	jsr via_IBSOUT
 	iny
 	cpy #5
 	bne -
diff --git a/c64/basic/print_packed_message.s b/c64/basic/print_packed_message.s
index 58481e82..7aac0876 100644
--- a/c64/basic/print_packed_message.s
+++ b/c64/basic/print_packed_message.s
@@ -38,7 +38,7 @@ found_message_in_token_stream:
 	beq +
 	jsr print_packed_word
 	lda #$20
-	jsr $ffd2
+	jsr via_IBSOUT
 	pla
 	tay
 	iny
@@ -47,7 +47,7 @@ found_message_in_token_stream:
 	pla
 	;; Rub out space at the end
 	lda #$14
-	jsr $ffd2
+	jsr via_IBSOUT
 	rts
 
 print_packed_word:
@@ -138,13 +138,13 @@ next_packed_word_char:
 	lsr
 	tax
 
-	;; Save Y so it doesn't get clobbered by $FFD2
+	;; Save Y so it doesn't get clobbered by CHROUT
 	tya
 	pha
 
 	;; X=1-14 = first 14 chars, so subtract one
 	lda packed_message_chars-1,x
-	jsr $FFD2
+	jsr via_IBSOUT
 
 	;; See if there is a char in the low nybl to print
 	pla
@@ -171,7 +171,7 @@ has_nybl:
 	
 	;; X=1-14 = first 14 chars, so subtract one
 	lda packed_message_chars-1,x
-	jsr $FFD2
+	jsr via_IBSOUT
 *
 	pla
 	tay
@@ -207,7 +207,7 @@ unpack_literal_char:
 	tya
 	pha
 	lda (temp_string_ptr),y
-	jsr $ffd2
+	jsr via_IBSOUT
 	pla
 	tay
 	rts
diff --git a/c64/basic/printf.s b/c64/basic/printf.s
index c1edc71c..85fa0cf8 100644
--- a/c64/basic/printf.s
+++ b/c64/basic/printf.s
@@ -112,7 +112,7 @@ not_hexword:
 
 not_pointer:	
 	;; Print character
-	jsr $ffd2
+	jsr via_IBSOUT
 
 printf_nextchar:
 	jsr printf_advance
@@ -148,11 +148,11 @@ printf_printhexbyte:
 	cmp #$3A
 	bcc +
 	adc #6
-*	jsr $ffd2
+*	jsr via_IBSOUT
 	pla
 	and #$0f
 	ora #$30
 	cmp #$3A
 	bcc +
 	adc #6
-*	jmp $ffd2
+*	jmp via_IBSOUT
diff --git a/c64/basic/select_device.s b/c64/basic/select_device.s
new file mode 100644
index 00000000..f5939033
--- /dev/null
+++ b/c64/basic/select_device.s
@@ -0,0 +1,19 @@
+
+select_device:
+
+	;; Take last device number, make sure it's a drive - 8 or above. Above 30,
+	;; although illegal for IEC we also consider a drive, as they exists
+	;; drivers assigning these numbers to CBM-DOS capable devices - like some
+	;; IEEE-488 carts.
+	;;
+	;; If current device is not a drive, set device to 8 (first drive number)
+	;; Device number is left in X, for SETFLS Kernal routine
+
+	;; Note: if tape support is introduced here, make sure DOS wedge won't get broken
+
+	ldx current_device_number
+	cpx #$08
+	bcs +
+	ldx #$08
+*
+	rts
diff --git a/c64/basic/via_vector.s b/c64/basic/via_vector.s
new file mode 100644
index 00000000..3cfc7480
--- /dev/null
+++ b/c64/basic/via_vector.s
@@ -0,0 +1,42 @@
+
+;;
+;; Helper routines for jumping via vectors, to be used with JSR
+;;
+;; Note: they are not in the order of low memory vectors, to avoid
+;;       similarity with the original ROMs
+
+via_ISAVE:
+	jmp (ISAVE)
+
+via_ILOAD:
+	jmp (ILOAD)
+
+via_ICLOSE:
+	jmp (ICLOSE)
+
+via_IOPEN:
+	jmp (IOPEN)
+
+via_ICHKIN:
+	jmp (ICHKIN)
+
+via_IBASIN:
+	jmp (IBASIN)
+
+via_IGETIN:
+	jmp (IGETIN)
+
+via_ICKOUT:
+	jmp (ICKOUT)
+
+via_IBSOUT:
+	jmp (IBSOUT)
+
+via_ICLRCH:
+	jmp (ICLRCH)
+
+via_ICLALL:
+	jmp (ICLALL)
+
+via_ISTOP:
+	jmp (ISTOP)
diff --git a/c64/basic/wedge_dos.s b/c64/basic/wedge_dos.s
new file mode 100644
index 00000000..e147e9fe
--- /dev/null
+++ b/c64/basic/wedge_dos.s
@@ -0,0 +1,230 @@
+
+;; START wedge support
+
+wedge_dos:
+
+	;; Close all the channels, so that wedge has full control
+	jsr via_ICLALL
+
+	;; Set file parameters,  channel 15 is a typical one for commands
+	jsr select_device ; sets X register
+	lda #$0F
+	ldy #$0F
+	jsr JSETFLS
+
+	;; Now we have to check what the user wants us to do
+
+	;; Check if user asked for a status
+	ldy #$00
+	lda (basic_current_statement_ptr), y
+	beq wedge_dos_status
+	
+	;; Check if asked for a directory
+	cmp #$24
+	beq wedge_dos_directory
+*
+	;; Check if asked to change drive number, or if it is a regular command
+	cmp #$30
+	bcc wedge_dos_command ; char code before 0
+	cmp #$3A
+	bcs wedge_dos_command ; char code after 9
+	iny
+	lda (basic_current_statement_ptr), y
+	beq wedge_dos_change_drive ; end of buffer
+	cmp #$20
+	beq wedge_dos_change_drive
+	jmp -
+
+wedge_dos_command:
+
+	;; Provide command name
+	jsr wedge_dos_setnam
+	
+	jsr JSETNAM
+	jsr via_IOPEN
+	bcs wedge_dos_basic_error
+
+	;; Retrieve status, print it if not OK
+	jsr via_ICLALL
+	jsr wedge_dos_status_get
+	lda BUF+0
+	cmp #$30 ; '0'
+	bne wedge_dos_status_print
+	lda BUF+1
+	cmp #$30 ; '0'
+	bne wedge_dos_status_print
+
+	;; Clean-up and exit
+	jmp wedge_dos_clean_exit
+
+wedge_dos_change_drive:
+
+	;; Reuse the line number parser for device number retrieval
+	jsr basic_parse_line_number
+	lda basic_line_number+1
+	beq +
+	jmp do_ILLEGAL_QUANTITY_error
+*
+	lda basic_line_number+0
+	cmp #$08
+	bpl +
+	bcs +
+	jmp do_ILLEGAL_DEVICE_NUMBER_error
+*
+	sta current_device_number
+	jmp basic_end_of_line
+
+wedge_dos_status_get:
+
+	;; Here the flow is mostly the same as in the example from
+	;; https://codebase64.org/doku.php?id=base:reading_the_error_channel_of_a_disk_drive
+
+	;; Set remaining file parameters, open the channel
+	lda #$00  ; empty file name
+	jsr JSETNAM
+	jsr via_IOPEN
+	bcs wedge_dos_basic_error
+
+	;; Set channel for input
+	ldx #$0F
+	jsr via_ICHKIN
+	bcs wedge_dos_basic_error
+	
+	ldy #$00
+*
+	cpy #$50 ; buffer overflow protection
+	beq +
+	jsr JREADST ; retrieve errors
+	;; XXX error in case of status != EOF
+	;; Print out everything retrieved from the drive
+	bne +
+	jsr via_IBASIN
+	bcs wedge_dos_basic_error
+	sta BUF, y
+	iny
+	jmp -
+*
+	rts
+
+wedge_dos_status:
+	jsr wedge_dos_status_get
+	;; FALLTROUGH
+
+wedge_dos_status_print:
+
+	;; Print buffered status
+	ldx #$00
+*
+	dey
+	bmi +
+	lda BUF, x
+	jsr via_IBSOUT
+	inx
+	bne -
+*
+	;; Clean-up and exit
+	jmp wedge_dos_clean_exit
+
+wedge_dos_directory:
+
+	;; First change the secondary address to the one suitable for
+	;; directory loading
+	;; XXX
+	lda #$00 ; logical device number
+	ldx current_device_number
+	ldy #$60
+	jsr JSETFLS
+
+	;; Provide file name
+	jsr wedge_dos_setnam
+
+	;; Open the file
+	jsr via_IOPEN
+	bcs wedge_dos_basic_error
+
+	;; Set channel for file reading
+	ldx #$00
+	jsr via_ICHKIN
+	bcs wedge_dos_basic_error
+
+	;; Ignore start address (2 first bytes) - XXX check for errors
+	jsr via_IBASIN
+	bcs wedge_dos_basic_error
+	jsr via_IBASIN
+	bcs wedge_dos_basic_error
+
+wedge_dos_directory_line:
+
+	;; Load a single line, reuse BASIC input buffer
+	ldy #$FF
+*
+	iny
+	jsr via_IBASIN
+	bcs wedge_dos_basic_error
+	sta BUF, y
+	cpy #$50
+	beq + ; line too long, terminate loading file
+	jsr JREADST
+	bne + ; end of file
+	cpy #$04 ; 2 bytes (pointer to next line) + 2 bytes (line number) 
+	bcc -
+	lda BUF, y
+	bne -
+	;; End of line, but not end of file
+	beq wedge_dos_directory_display
+*
+	lda #K_STS_END_OF_FILE
+	sta IOSTATUS ; make sure end of file is marked
+	;; FALLTROUGH
+
+wedge_dos_directory_display:
+
+	cpy #$05 ; protection against malformed directory
+	bcc wedge_dos_clean_exit
+
+	lda #$00 ; extra protection agains buffer overflow
+	sta BUF, y
+
+	;; Display line
+	ldx #<BUF
+	stx basic_current_line_ptr+0
+	ldx #>BUF
+	stx basic_current_line_ptr+1
+	ldx #basic_current_line_ptr
+	jsr list_single_line
+
+	;; Read & display next line or quit
+	lda IOSTATUS
+	beq wedge_dos_directory_line
+	;; FALLTROUGH
+
+wedge_dos_clean_exit:
+	jsr via_ICLALL
+	;; Print new line
+	lda #$0D
+	jsr via_IBSOUT
+	jmp basic_end_of_line
+
+wedge_dos_basic_error:
+	pha
+	jsr via_ICLALL
+	pla
+	tax
+	dex
+	jmp do_basic_error
+
+wedge_dos_setnam:
+	;; Now determine the length of the 'file' name
+	ldy #$FF
+*
+	iny
+	lda (basic_current_statement_ptr), y
+	bne -
+	
+	;; Set the name to open
+	tya
+	ldx basic_current_statement_ptr+0
+	ldy basic_current_statement_ptr+1
+	jmp JSETNAM
+
+;; END wedge support
diff --git a/c64/kernal/,aliases.s b/c64/kernal/,aliases.s
index 4dc694f1..b769b149 100644
--- a/c64/kernal/,aliases.s
+++ b/c64/kernal/,aliases.s
@@ -3,27 +3,18 @@
 ;	(And only those for now that we feel the need to implement initially)
 ;	(https://www.c64-wiki.com/wiki/Zeropage)
 
-	.alias TXTTAB $2B
-	.alias IOSTATUS $90
-	; Keys down clears bits. STOP=bit 7, C= bit 6, SPACE bit 4, CTRL bit 2
-	.alias BUCKYSTATUS $91
 	.alias kernal_load_or_verify_flag $93
 	.alias current_file_num $98
-	.alias input_device_number $99
-	; bit 6 = error messages, bit 7 = control messages
-	.alias kernal_message_control_flags $9d
-	.alias jiffy_clock_24bits $a0
+	.alias input_device_number DFLTN
 	.alias cassette_buffer_bytes_used $A6
 	.alias load_or_scroll_temp_pointer $AC
 	;; We also use the following for temp colour pointer when scrolling
 	.alias load_save_verify_end_address $AE
 	.alias cassette_buffer_ptr $B2
-	.alias current_filename_length $B7
 	.alias current_logical_filenum $B8
 	.alias current_secondary_address $B9
 	.alias current_device_number $BA
 	.alias current_filename_ptr $BB
-	.alias load_save_start_ptr $C1
 	.alias load_save_end_ptr $C3
 	.alias last_key_matrix_position $C5
 	.alias keys_in_key_buffer $C6
@@ -50,15 +41,11 @@
 	.alias keyboard_decoding_table_ptr $F5
 	.alias rs232_rx_buffer_ptr $F7
 	.alias rs232_tx_buffer_ptr $F9
-
-
+	
 	; "Compute's Mapping the 64" book
 	.alias keyboard_buffer $0277
-	.alias MEMSTR $0281
-	.alias MEMSIZ $0283 	; NOTE: Mapping the 64 erroniously has the hex as $282, while the DEC is correct
 	.alias text_colour $0286 ; p55
 	.alias colour_under_cursor $0287 ; p56
-	.alias HIBASE $0288     ; p56 (high byte of start of screen)
 	.alias key_buffer_size $0289 ; p57
 
 	;; 0 = cursor keys, insert, delete and space repeat, but nothing else
@@ -74,7 +61,6 @@
 	.alias keyboard_decoding_ptr $028F
 	.alias enable_case_switch $0291
 	.alias screen_scroll_disable $0292
-	.alias pal_or_ntsc $02A6
 
 	;; Under-ROM routines
 	;; (BASIC also includes them. XXX - We should de-duplicate them in a safe manner)
@@ -84,5 +70,4 @@
 	.alias poke_under_roms tiny_nmi_handler+poke_under_roms_routine-tiny_nmi_handler_routine
 	.alias memmap_allram tiny_nmi_handler+memmap_allram_routine-tiny_nmi_handler_routine
 	.alias memmap_normal tiny_nmi_handler+memmap_normal_routine-tiny_nmi_handler_routine
-	
-	
+
diff --git a/c64/kernal/,target_generic/,hooks_generic.s b/c64/kernal/,target_generic/,hooks_generic.s
new file mode 100644
index 00000000..a2c8c1a6
--- /dev/null
+++ b/c64/kernal/,target_generic/,hooks_generic.s
@@ -0,0 +1,6 @@
+
+;; Target-specific hooks
+
+
+.macro TARGET_HOOK_LOAD
+.macend
diff --git a/c64/kernal/,target_mega65/,hooks_mega65.s b/c64/kernal/,target_mega65/,hooks_mega65.s
new file mode 100644
index 00000000..a2c8c1a6
--- /dev/null
+++ b/c64/kernal/,target_mega65/,hooks_mega65.s
@@ -0,0 +1,6 @@
+
+;; Target-specific hooks
+
+
+.macro TARGET_HOOK_LOAD
+.macend
diff --git a/c64/kernal/,target_ultimate64/,aliases_ultimate64.s b/c64/kernal/,target_ultimate64/,aliases_ultimate64.s
new file mode 100644
index 00000000..a4aabfaf
--- /dev/null
+++ b/c64/kernal/,target_ultimate64/,aliases_ultimate64.s
@@ -0,0 +1,57 @@
+
+;; Registers according to Ultimate 64 Command Interface description,
+;; https://1541u-documentation.readthedocs.io/en/latest/command%20interface.html
+;; and ultimate_dos_v1.0.pdf and command_interface_v1.0.pdf by Gideon Zweijtzer
+
+	;; Command interface registers
+	.alias U64_CONTROL                 $DF1C ; write
+	.alias U64_STATUS                  $DF1C ; read
+	.alias U64_COMMAND_DATA            $DF1D ; write
+	.alias U64_IDENTIFICATION          $DF1D ; read
+	.alias U64_RESPONSE_DATA           $DF1E ; read only
+	.alias U64_STATUS_DATA             $DF1F ; read only
+
+	;; Constant for U64_IDENTIFICATION register
+	.alias U64_MAGIC_ID                $C9
+
+	;; Constants for U64_CONTROL register
+	.alias U64_CTRL_BIT_PUSH_CMD       $01
+	.alias U64_CTRL_BIT_DATA_ACC       $02
+	.alias U64_CTRL_BIT_ABORT          $04
+	.alias U64_CTRL_BIT_CLR_ERR        $08
+
+	;; Constants for U64_STATUS register
+	.alias U64_STAT_BIT_CMD_BUSY       $01
+	.alias U64_STAT_BIT_DATA_ACC       $02
+	.alias U64_STAT_BIT_ABORT_P        $04
+	.alias U64_STAT_BIT_ERROR          $08
+	.alias U64_STAT_MASK_STATE         $30 ; two bits!
+	.alias U64_STAT_BIT_STAT_AV        $40
+	.alias U64_STAT_BIT_DATA_AV        $80
+
+	;; Interface targets
+	.alias U64_TARGET_DOS1             $01
+	.alias U64_TARGET_DOS2             $02
+
+	;; DOS command codes
+	.alias U64_DOS_CMD_IDENTIFY        $01
+	.alias U64_DOS_CMD_OPEN_FILE       $02
+	.alias U64_DOS_CMD_CLOSE_FILE      $03
+	.alias U64_DOS_CMD_READ_DATA       $04
+	.alias U64_DOS_CMD_WRITE_DATA      $05
+	.alias U64_DOS_CMD_FILE_SEEK       $06
+	.alias U64_DOS_CMD_FILE_INFO       $07
+	.alias U64_DOS_CMD_CHANGE_DIR      $11
+	.alias U64_DOS_CMD_GET_PATH        $12
+	.alias U64_DOS_CMD_OPEN_DIR        $13
+	.alias U64_DOS_CMD_READ_DIR        $14
+	.alias U64_DOS_CMD_COPY_UI_PATH    $15
+	.alias U64_DOS_CMD_LOAD_REU        $21
+	.alias U64_DOS_CMD_SAVE_REU        $22
+	.alias U64_DOS_CMD_ECHO            $F0
+
+	;; DOS file opening constants 
+	.alias U64_FA_READ                 $01
+	.alias U64_FA_WRITE                $02
+	.alias U64_FA_CREATE_NEW           $03
+	.alias U64_FA_CREATE_ALWAYS        $04
diff --git a/c64/kernal/,target_ultimate64/,hooks_ultimate64.s b/c64/kernal/,target_ultimate64/,hooks_ultimate64.s
new file mode 100644
index 00000000..03f6eeb8
--- /dev/null
+++ b/c64/kernal/,target_ultimate64/,hooks_ultimate64.s
@@ -0,0 +1,9 @@
+
+;; Target-specific hooks
+
+
+.macro TARGET_HOOK_LOAD
+	;; XXX disabled for now - the current file opening API is not
+	;;     really suitable for easy usage from Kernal
+	;; jsr u64_load
+.macend
diff --git a/c64/kernal/,target_ultimate64/u64_load.s.disabled b/c64/kernal/,target_ultimate64/u64_load.s.disabled
new file mode 100644
index 00000000..07ddc298
--- /dev/null
+++ b/c64/kernal/,target_ultimate64/u64_load.s.disabled
@@ -0,0 +1,130 @@
+
+;;
+;; LOAD routine hook for fast loading via UltiDOS
+;;
+
+
+u64_load:
+
+	;; First check whether the command interface is enabled
+	lda U64_IDENTIFICATION
+	cmp #U64_MAGIC_ID
+	beq +
+
+u64_load_skip:
+	rts
+*
+	;; XXX find out which device number softIEC is mapped to
+	lda current_device_number
+	cmp #$20 ; for now use device number 32
+	bne u64_load_skip
+	
+	;; Takeover the flow completely
+	pla
+	pla
+
+	;; Display SEARCHING FOR + filename
+	jsr lvs_display_searching_for
+
+	;; Whatever the interface was doing - ask to abort it
+	jsr u64_load_abort
+	
+	;; Send a command to open the file
+	lda #U64_DOS_CMD_OPEN_FILE
+	jsr u64_load_send_cmd
+	lda #U64_FA_READ
+	jsr u64_load_send_cmd
+	jsr u64_load_send_filename
+	jsr u64_load_finalize_cmd
+	
+	;; Check status
+	jsr u64_load_check_status
+	bcs lvs_file_not_found_error
+
+	;; Load first two bytes to determine start address
+
+	;; XXX
+	
+	jsr printf
+	.byte "DBG: NOT IMPLEMENTED",$0D,0
+
+	jmp lvs_wrap_around_error
+	rts
+
+u64_load_abort:
+	lda #U64_CTRL_BIT_ABORT
+	sta U64_CONTROL
+*
+	lda U64_STATUS
+	bne -
+	rts
+
+u64_load_send_cmd:
+
+	ldx #U64_TARGET_DOS2
+	stx U64_COMMAND_DATA ; target
+	sta U64_COMMAND_DATA ; command code
+	rts
+
+u64_load_send_filename:
+	ldy #0
+u64_load_send_filename_loop:
+	cpy FNLEN
+	bne+
+	rts
+*
+	ldx #<current_filename_ptr
+	jsr peek_under_roms
+	iny
+	
+	sta U64_COMMAND_DATA
+	jmp u64_load_send_filename_loop
+
+u64_load_finalize_cmd:
+	;; Push the command for execution
+	lda #U64_CTRL_BIT_PUSH_CMD
+	sta U64_CONTROL
+	;; Wait till it is complete
+*
+	lda U64_STATUS
+	and #U64_STAT_BIT_CMD_BUSY
+	bne -
+	rts
+
+u64_load_check_status:
+	;; Wait till status is available
+	lda U64_STATUS
+	and #U64_STAT_BIT_STAT_AV
+	beq u64_load_check_status
+
+	;; Status is ready - check the first character
+	lda U64_STATUS_DATA
+	jsr JCHROUT ; XXX for test only
+	cmp #$30 ; '0'
+	bne u64_load_check_status_wrong
+
+	;; Check the second status character
+	lda U64_STATUS
+	and #U64_STAT_BIT_STAT_AV
+	beq u64_load_check_status_ok
+	lda U64_STATUS_DATA
+	jsr JCHROUT ; XXX for test only
+	cmp #$30 ; '0'
+	beq u64_load_check_status_ok
+
+	;; FALLTROUGH
+u64_load_check_status_wrong:
+	sec
+	bcs +
+u64_load_check_status_ok:
+	clc
+*
+	;; Now empty the status queue
+	lda U64_STATUS
+	and #U64_STAT_BIT_STAT_AV
+	beq +
+	lda U64_STATUS_DATA
+	jsr JCHROUT ; XXX for test only
+	jmp -
+*
+	rts
diff --git a/c64/kernal/acptr.s b/c64/kernal/acptr.s
index d9ac012f..8d3da68f 100644
--- a/c64/kernal/acptr.s
+++ b/c64/kernal/acptr.s
@@ -1,3 +1,15 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 274
+;; - [CM64] Compute's Mapping the Commodore 64 - page 224/225
+;;
+;; CPU registers that has to be preserved (see [RG64]): .Y
+;;
+
+
 acptr:
-	rts
+	jsr kernalstatus_reset
+	jmp iec_rx_byte
+
diff --git a/c64/kernal/chkin.s b/c64/kernal/chkin.s
deleted file mode 100644
index 99937d2e..00000000
--- a/c64/kernal/chkin.s
+++ /dev/null
@@ -1,3 +0,0 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
-chkin:
-	rts
diff --git a/c64/kernal/chkinout.s b/c64/kernal/chkinout.s
new file mode 100644
index 00000000..1075665c
--- /dev/null
+++ b/c64/kernal/chkinout.s
@@ -0,0 +1,143 @@
+
+;;
+;; Official Kernal routines, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 275 (CHKIN) / 276 (CKOUT)
+;; - [CM64] Compute's Mapping the Commodore 64 - page 229
+;;
+;; CPU registers that has to be preserved (see [RG64]): .Y
+;;
+
+
+;; CHKIN implementation
+
+chkin:
+
+	;; Store Y for preservation
+	tya
+	pha
+
+	;; Reset status
+	jsr kernalstatus_reset
+
+	;; First retrieve the FAT/LAT/SAT table index (and check if file is open)
+
+	txa
+	jsr find_fls
+	bcs chkinout_file_not_open
+
+	;; Now we have table index in Y - first filter out unsuitable devices
+
+	lda FAT,Y
+	cmp #$01
+	beq chkinout_device_not_present ; tape not implemented
+	cmp #$02
+	beq chkinout_device_not_present ; RS-232 not implemented
+
+	;; Fail if the file is open for writing (secondary address 1)
+	
+	lda LAT, Y
+	cmp #$01
+	beq chkinout_file_not_input
+
+	;; For IEC devices, send TALK + TKSA first
+	lda FAT,Y
+	jsr iec_check_devnum
+	bcs chkin_set_device
+	
+	jsr talk
+	bcs chkinout_device_not_present ; don't set DFLTN in case of failure
+
+	lda LAT, Y
+	jsr tksa
+	bcs chkinout_device_not_present
+
+chkin_set_device:
+	lda FAT,Y
+	sta DFLTN
+	clc ; for success
+	;; FALLTROUGH
+
+;; Common part for booth CHKIN and CKOUT
+
+chkinout_end:
+	tax
+	pla
+	tay
+	txa
+	rts
+
+chkinout_file_not_open:
+	pla
+	tay
+	jmp kernalerror_FILE_NOT_OPEN
+
+chkinout_device_not_present:
+	pla
+	tay
+	jsr kernalstatus_DEVICE_NOT_FOUND
+	jmp kernalerror_DEVICE_NOT_FOUND
+
+chkinout_file_not_input:
+	pla
+	tay
+	jmp kernalerror_FILE_NOT_INPUT
+
+chkinout_file_not_output:
+	pla
+	tay
+	jmp kernalerror_FILE_NOT_OUTPUT
+
+chkinout_common:
+
+;; CKOUT implementation
+
+ckout:
+
+	;; Store Y for preservation
+	tya
+	pha
+
+	;; Reset status
+	jsr kernalstatus_reset
+
+	;; First retrieve the FAT/LAT/SAT table index (and check if file is open)
+
+	txa
+	jsr find_fls
+	bcs chkinout_file_not_open
+
+	;; Now we have table index in Y - first filter out unsuitable devices
+
+	lda FAT,Y
+	cmp #$01
+	beq chkinout_device_not_present ; tape not implemented
+	cmp #$02
+	beq chkinout_device_not_present ; RS-232 not implemented
+
+	cmp #$00
+	beq chkinout_file_not_output ; cannot output to keyboard - XXX check real ROM behaviour
+
+	;; Fail if the file is open for reading (secondary address 0)
+	
+	lda LAT, Y
+	beq chkinout_file_not_output
+
+	;; For IEC devices, send LISTEN + SECOND first
+	lda FAT,Y
+	jsr iec_check_devnum
+	bcs chkout_set_device
+
+	jsr listen
+	bcs chkinout_device_not_present ; don't set DFLTO in case of failure
+
+	lda LAT, Y
+	jsr second
+	bcs chkinout_device_not_present
+
+chkout_set_device:
+	lda FAT,Y
+	sta DFLTO
+	clc ; for success
+
+	jmp chkinout_end
diff --git a/c64/kernal/chkout.s b/c64/kernal/chkout.s
deleted file mode 100644
index 262a4c59..00000000
--- a/c64/kernal/chkout.s
+++ /dev/null
@@ -1,3 +0,0 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
-chkout:
-	rts
diff --git a/c64/kernal/chrin.s b/c64/kernal/chrin.s
index c60c5040..8a84f5d6 100644
--- a/c64/kernal/chrin.s
+++ b/c64/kernal/chrin.s
@@ -1,14 +1,53 @@
-				; Function defined on pp272-273 of C64 Programmers Reference Guide
-	;; Compute's Mapping the 64, p228
-	;;  Reads a byte of input, unless from keyboard.
-	;; If from keyboard, then it gets a whole line of input, and returns the first char.
-	;; Repeated calls after that read out the successive bytes of the line of input.
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 277/278
+;; - [CM64] Compute's Mapping the Commodore 64 - page 228
+;;
+;; CPU registers that has to be preserved (see [RG64]): .Y
+;;
+
+;; XXX keyboard part currently does not preserve register Y, to be fixed!
+
+;; Reads a byte of input, unless from keyboard.
+;; If from keyboard, then it gets a whole line of input, and returns the first char.
+;; Repeated calls after that read out the successive bytes of the line of input.
+
 chrin:
+
+	;; Determine the device number
+	lda DFLTN
+
+	beq chrin_keyboard ; #$00 - keyboard
+	;; XXX add screen support
+
+	jsr iec_check_devnum
+	bcc chrin_iec
+	jmp lvs_device_not_found_error ;  not a supported device
+
+chrin_iec:
+
+	jsr JACPTR
+	bcs chrin_done_fail
+	;; FALLTROUGH
+
+chrin_done:
+	clc ; indicate success
+	rts
+
+chrin_done_fail:
+	sec ; indicate failure
+	rts
+
+chrin_keyboard:
+
 	;; Save X
 	txa
 	pha
 
-chrin_repeat:	
+chrin_repeat:
+
 	;; Do we have a line of input we are currently returning?
 	;; If so, return the next byte, and clear the flag when we reach the end.
 
@@ -165,7 +204,7 @@ not_shifted:
 	clc
 	adc #$40
 	
+	;; FALLTROUGH
+not_vendor:
 	rts
-not_vendor:	
-	
-	rts
+
diff --git a/c64/kernal/chrout.s b/c64/kernal/chrout.s
index 02503fa7..6f340a0f 100644
--- a/c64/kernal/chrout.s
+++ b/c64/kernal/chrout.s
@@ -1,24 +1,96 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 278/279
+;; - [CM64] Compute's Mapping the Commodore 64 - page 228
+;;
+;; CPU registers that has to be preserved (see [RG64]): .Y
+;;
+
+
 chrout:
-	;; Crude implementation of character output	
+
+	sta last_printed_character_ascii
 
 	;; Save X and Y values
 	;; (Confirmed by writing a test program that X and Y
 	;; don't get modified, in agreement with C64 PRG's
 	;; description of CHROUT)
-	sta last_printed_character_ascii
 	txa
 	pha
 	tya
 	pha
 	php
-	sei
-	
+
+	;; Determine the device number
+	lda DFLTO
+
+	cmp #$03 ; screen
+	beq chrout_screen
+
+	jsr iec_check_devnum
+	bcs chrout_done_unknown_device ; not a supported device
+
+chrout_iec:
+
+	lda last_printed_character_ascii
+	jsr JCIOUT
+	bcc chrout_done
+
+	;; FALLTROUGH
+
+chrout_done_fail:
+	jsr show_cursor_if_enabled
+
+	plp
+
+	;; Restore X and Y
+	pla
+	tay
+	pla
+	tax
+	sec ; indicate failure
+	rts
+
+chrout_done_unknown_device:
+	jsr show_cursor_if_enabled
+
+	plp
+
+	;; Restore X and Y
+	pla
+	tay
+	pla
+	tax
+
+	;; End wioth error
+	jmp lvs_device_not_found_error
+
+chrout_done:
+	jsr show_cursor_if_enabled
+
+	plp
+
+	;; Restore X and Y
+	pla
+	tay
+	pla
+	tax
+	lda last_printed_character_ascii
+	clc ; indicate success
+	rts
+
+chrout_screen:
+
+	;; Crude implementation of character output	
+	sei ;; XXX why do we need to disable interrupts?
+
 	jsr hide_cursor_if_visible
-	
+
 	lda last_printed_character_ascii
 	tax
-	
+
 	;; Check for special characters
 
 	cmp #$00
@@ -32,7 +104,7 @@ not_00:
 	bne not_0a
 	jmp chrout_done
 not_0a:
-	
+
 	;; Carriage return
 	cmp #$0d
 	bne not_0d
@@ -370,20 +442,7 @@ not_quote:
 	sta current_screen_x
 	jmp screen_advance_to_next_line
 no_screen_advance_to_next_line:
-
-chrout_done:
-	jsr show_cursor_if_enabled
-	
-	plp
-	
-	;; Restore X and Y, set carry to mark success on exit
-	pla
-	tay
-	pla
-	tax
-	lda last_printed_character_ascii
-	clc 			; indicate success
-	rts
+	jmp chrout_done
 
 screen_grow_logical_line:
 	ldy current_screen_y
diff --git a/c64/kernal/cint.s b/c64/kernal/cint.s
index bf760279..973def0d 100644
--- a/c64/kernal/cint.s
+++ b/c64/kernal/cint.s
@@ -1,5 +1,14 @@
-	;; Function defined on pp272-273 of C64 Programmers Reference Guide 
-	;; Compute's Mapping the 64 p215
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 280
+;; - [CM64] Compute's Mapping the Commodore 64 - page 242
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
+
 cint:
 	jsr setup_vicii
 	
@@ -34,6 +43,9 @@ cint:
 	;; Put non-zero value in enable_case_switch
 	stx enable_case_switch
 	
+	;; Set default I/O devices (see SCINIT description at http://sta.c64.org/cbm64krnfunc.html)
+	jsr clrchn_reset
+	
 	;; Fallthrough/jump to screen clear routine (Compute's Mapping the 64 p215)
 	jmp clear_screen
 
diff --git a/c64/kernal/ciout.s b/c64/kernal/ciout.s
index e389806a..26095a85 100644
--- a/c64/kernal/ciout.s
+++ b/c64/kernal/ciout.s
@@ -1,3 +1,37 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 279/280
+;; - [CM64] Compute's Mapping the Commodore 64 - page 224
+;;
+;; CPU registers that has to be preserved (see [RG64]): .X, .Y
+;;
+
+
 ciout:
+
+	pha
+	lda C3PO
+	bne ciout_send_byte
+
+	;; Nothing to send - set buffer as valid, store byte there
+	inc C3PO
+
+	;; Clear carry flag to indicate success
+	clc
+	
+ciout_store_in_buffer:
+
+	;; Store in the buffer data to be sent next, return
+	pla
+	sta BSOUR
 	rts
+	
+ciout_send_byte:
+
+	clc ; don't send with EOI
+	jsr iec_tx_byte
+	inc C3PO ; iec_tx_byte sets it to 0, but we still have something to send
+	jmp ciout_store_in_buffer
+
diff --git a/c64/kernal/clall.s b/c64/kernal/clall.s
new file mode 100644
index 00000000..ba595c20
--- /dev/null
+++ b/c64/kernal/clall.s
@@ -0,0 +1,38 @@
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 281
+;; - [CM64] Compute's Mapping the Commodore 64 - page 230
+;;
+;; CPU registers that has to be preserved (see [RG64]): .Y
+;;
+
+
+clall:
+
+	;; Store .Y register
+	tya
+	pha
+
+	;; Original routine probably just sets LDTND to 0, but this is not really safe,
+	;; so we actually close all the channels; at least IDE64 does the same for
+	;; it's channels, see CLALL description in the IDE64 User's Guide
+*
+	ldy LDTND
+	beq +
+	dey
+	lda LAT, y
+	jsr close ; XXX jump through ICLOSE?
+	jmp -
+*
+	;; Restore .Y register
+	pla
+	tay
+
+	;; 'C64 Programmers Reference Guide', page 281, claims it calls CLRCHN too
+	jsr clrchn
+	
+	;; Not sure whether original Kernal does so, but it seems sane to also clear possible errors
+	jmp kernalstatus_reset
+
diff --git a/c64/kernal/close.s b/c64/kernal/close.s
index df7f3603..fc8e0a8c 100644
--- a/c64/kernal/close.s
+++ b/c64/kernal/close.s
@@ -1,3 +1,59 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 281/282
+;; - [CM64] Compute's Mapping the Commodore 64 - page 229/230
+;; - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc (IEC command)
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
 close:
+
+	;; XXX this needs more testing (opening 10 files at once, closing in various orders, etc) once the code is more mature
+
+	;; Find the LAT / SAT / FAT entry which LAT corresponds to A
+
+	jsr find_fls
+	bcs close_error_not_found ;; XXX can we report error in IOSTATUS here?
+
+	;; We have the entry index in Y - check whether this is IEC device
+	lda FAT, y
+	jsr iec_check_devnum
+	bcs close_remove_from_table
+
+	;; IEC device
+
+	jsr iec_tx_flush ; make sure no byte is awaiting
+*
+	lda SAT, y ; get secondary address
+	ora $E0 ; CLOSE command
+	sta IEC_TMP2
+	jsr iec_tx_command
+	bcs close_remove_from_table
+	jsr iec_tx_command_finalize
+	
+close_remove_from_table:
+	;; Remove channel from the table
+	iny
+	cpy #$0A
+	bpl +
+	lda LAT, y
+	sta LAT-1, y
+	lda FAT, y
+	sta FAT-1, y
+	lda SAT, y
+	sta SAT-1, y
+	jmp close_remove_from_table
+*
+	;; Decrement the list size variable
+	dec LDTND
+
+	clc ; report success - not sure if original CLOSE does this, but it's nevertheless a good practice
+	rts
+
+close_error_not_found:
+
+	sec ; report success - not sure if original CLOSE does this, but it's nevertheless a good practice
 	rts
diff --git a/c64/kernal/close_all_files.s b/c64/kernal/close_all_files.s
deleted file mode 100644
index c0555315..00000000
--- a/c64/kernal/close_all_files.s
+++ /dev/null
@@ -1,2 +0,0 @@
-close_all_files:
-	rts
diff --git a/c64/kernal/clrchn.s b/c64/kernal/clrchn.s
index 729b8dde..3cc53078 100644
--- a/c64/kernal/clrchn.s
+++ b/c64/kernal/clrchn.s
@@ -1,3 +1,36 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 282
+;; - [CM64] Compute's Mapping the Commodore 64 - page 230
+;;
+;; CPU registers that has to be preserved (see [RG64]): .Y
+;;
+
+
 clrchn:
+
+	;; Handle IEC input device
+	lda DFLTN
+	jsr iec_check_devnum
+	bcs +
+	;; Previous device was IEC one - send UNTALK first
+	jsr untlk
+*
+	;; Restore output device to default
+	lda DFLTO
+	jsr iec_check_devnum
+	bcs +
+	;; Handle IEC output device
+	jsr unlsn
+*
+clrchn_reset: ;; entry needed by CHRIN
+	;; Set input device number to keyboard
+	lda #$00
+	sta DFLTN
+	;; Set output device number to screen
+	lda #$03
+	sta DFLTO
+
 	rts
diff --git a/c64/kernal/errors.s b/c64/kernal/errors.s
index 751a2194..1f18f5e1 100644
--- a/c64/kernal/errors.s
+++ b/c64/kernal/errors.s
@@ -1,6 +1,88 @@
 
+;; Kernal error codes are described in 'Commodore 64 Programmer's Reference Guide', page 306
 
-kernalerror_DEVICE_NOT_FOUND:
-	lda #$05
+kernalerror_ROUTINE_TERMINATED: ; by a STOP key
+	lda #K_ERR_ROUTINE_TERMINATED
 	sec
 	rts
+
+kernalerror_TOO_MANY_OPEN_FILES:
+	lda #K_ERR_TOO_MANY_OPEN_FILES
+	sec
+	rts
+
+kernalerror_FILE_ALREADY_OPEN:
+	lda #K_ERR_FILE_ALREADY_OPEN
+	sec
+	rts
+
+kernalerror_FILE_NOT_OPEN:
+	lda #K_ERR_FILE_NOT_OPEN
+	sec
+	rts
+
+kernalerror_FILE_NOT_FOUND:
+	lda #K_ERR_FILE_NOT_FOUND
+	sec
+	rts
+
+kernalerror_DEVICE_NOT_FOUND:
+	lda #K_ERR_DEVICE_NOT_FOUND
+	sec
+	rts
+
+kernalerror_FILE_NOT_INPUT:
+	lda #K_ERR_FILE_NOT_INPUT
+	sec
+	rts
+
+kernalerror_FILE_NOT_OUTPUT:
+	lda #K_ERR_FILE_NOT_OUTPUT
+	sec
+	rts
+
+kernalerror_FILE_NAME_MISSING:
+	lda #K_ERR_FILE_NAME_MISSING
+	sec
+	rts
+
+kernalerror_ILLEGAL_DEVICE_NUMBER:
+	lda #K_ERR_ILLEGAL_DEVICE_NUMBER
+	sec
+	rts
+
+kernalerror_TOP_MEM_RS232:
+	lda #K_ERR_TOP_MEM_RS232
+	sec
+	rts
+
+;; Kernal status codes are described in 'Commodore 64 Programmer's Reference Guide', page 292
+
+kernalstatus_reset:
+	lda #$00
+	sta IOSTATUS
+	rts
+
+kernalstatus_TIMEOUT_WRITE: ;; XXX detect this!
+	lda IOSTATUS
+	ora #K_STS_TIMEOUT_WRITE
+	sta IOSTATUS
+	rts
+
+kernalstatus_TIMEOUT_READ: ;; XXX detect this!
+	lda IOSTATUS
+	ora #K_STS_TIMEOUT_READ
+	sta IOSTATUS
+	rts
+
+kernalstatus_EOI:
+	lda IOSTATUS
+	ora #K_STS_EOI
+	sta IOSTATUS
+	rts
+
+kernalstatus_DEVICE_NOT_FOUND:
+	lda IOSTATUS
+	ora #K_STS_DEVICE_NOT_FOUND
+	sta IOSTATUS
+	rts
diff --git a/c64/kernal/fda3.ioinit.s b/c64/kernal/fda3.ioinit.s
index a63b91a6..fd579b03 100644
--- a/c64/kernal/fda3.ioinit.s
+++ b/c64/kernal/fda3.ioinit.s
@@ -1,4 +1,13 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 285
+;; - [CM64] Compute's Mapping the Commodore 64 - page 238
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
 ioinit:
 
 	; Set $00/$01 port mode and value
@@ -39,4 +48,7 @@ ioinit:
 	lda #$3b
 	sta $dd02
 	
+	;; Set IEC bus oto its initial idle state
+	jsr iec_set_idle
+	
 	rts
diff --git a/c64/kernal/fff3.s b/c64/kernal/fff3.s
deleted file mode 100644
index 4870c7ba..00000000
--- a/c64/kernal/fff3.s
+++ /dev/null
@@ -1,9 +0,0 @@
-; $FFF3 - Get page of IO devices
-; Returns Y=$DC, X=$00
-; (http://codebase64.org/doku.php?id=base:kernalreference)
-;
-; As there is nothing between here and $FFFA, we can just hard code this in place.
-LDY #$DC
-LDX #$00
-RTS
-
diff --git a/c64/kernal/findfls.s b/c64/kernal/findfls.s
new file mode 100644
index 00000000..403139e0
--- /dev/null
+++ b/c64/kernal/findfls.s
@@ -0,0 +1,24 @@
+
+;; Just a helper routines
+
+;; Find the LAT / SAT / FAT entry index where LAT corresponds to A, returns index in Y
+;; Carry flag set means not found
+
+find_fls:
+
+	ldy LDTND
+	beq find_fls_not_found ; table empty
+*
+	dey
+	bmi find_fls_not_found ; no more entries
+	cmp LAT, y
+	bne - ; does not match, try the next one
+
+	clc
+	rts
+
+find_fls_not_found:
+
+	sec
+	rts
+
diff --git a/c64/kernal/get_screen_size.s b/c64/kernal/get_screen_size.s
deleted file mode 100644
index ff7be9a0..00000000
--- a/c64/kernal/get_screen_size.s
+++ /dev/null
@@ -1,2 +0,0 @@
-get_screen_size:
-	rts
diff --git a/c64/kernal/getin.s b/c64/kernal/getin.s
index 6df398c1..e8961cb4 100644
--- a/c64/kernal/getin.s
+++ b/c64/kernal/getin.s
@@ -1,4 +1,15 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 283
+;; - [CM64] Compute's Mapping the Commodore 64 - page 227/228
+;;
+;; CPU registers that has to be preserved (see [RG64]): .X, .Y
+;;
+
+;; XXX currently does not preserve registers, to be fixed!
+
 getin:
 
 	;; Wait for a key
diff --git a/c64/kernal/iec/iec_check_devnum.s b/c64/kernal/iec/iec_check_devnum.s
new file mode 100644
index 00000000..e5e354fa
--- /dev/null
+++ b/c64/kernal/iec/iec_check_devnum.s
@@ -0,0 +1,22 @@
+
+;;
+;; Checks whether device number (in .A) is a correct IEC device number
+;;
+;; Preserves .A, .X and .Y
+;;
+
+iec_check_devnum:
+	;; 0, 1, 2, or 3 are illegal - reserved for non-IEC devices on Commodore
+	cmp #$04
+	bcs +
+	;; FALLTROUGH
+iec_check_devnum_failed:
+	sec ; indicate non-IEC device
+	rts
+*
+	;; 31 and above are illegal too, due to IEC command encoding scheme,
+	;; see https://www.pagetable.com/?p=1031
+	cmp #$1F
+	bcs iec_check_devnum_failed
+	;; Carry is clear here - indicates IEC device
+	rts
diff --git a/c64/kernal/iec/iec_cmd_close.s b/c64/kernal/iec/iec_cmd_close.s
new file mode 100644
index 00000000..60c30a96
--- /dev/null
+++ b/c64/kernal/iec/iec_cmd_close.s
@@ -0,0 +1,16 @@
+
+;;
+;; Kernal internal IEC routine
+;;
+;; - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc
+;;
+
+iec_cmd_close:
+
+	jsr iec_check_channel_openclose
+	bcc +
+	jmp kernalerror_FILE_NOT_INPUT
+*
+	ora #$E0
+
+	jmp common_open_close_unlsn_second
diff --git a/c64/kernal/iec/iec_cmd_open.s b/c64/kernal/iec/iec_cmd_open.s
new file mode 100644
index 00000000..aa23a2c5
--- /dev/null
+++ b/c64/kernal/iec/iec_cmd_open.s
@@ -0,0 +1,42 @@
+
+;;
+;; Kernal internal IEC routine
+;;
+;; - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc
+;;
+
+
+iec_cmd_open: ; similar to TKSA, but without turnaround
+
+	jsr iec_check_channel_openclose
+	bcc +
+	jmp kernalerror_FILE_NOT_INPUT
+*
+	ora #$F0
+
+	;; FALLTROUGH
+
+common_open_close_unlsn_second: ; common part of several commands
+
+	sta IEC_TMP2
+	jsr iec_tx_command
+	bcs + ; branch if error
+	jmp iec_tx_command_finalize
+*
+	rts
+
+iec_check_channel_openclose:
+	;; Due to OPEN/CLOSE/TKSA/SECOND command encoding (see https://www.pagetable.com/?p=1031),
+	;; allowed channels are 0-15; report error if out of range
+	cmp #$10
+	bcc + 
+	;; Workaround to allow reading executable files and disk directory
+	;; using OPEN routine - see https://www.pagetable.com/?p=273 for
+	;; example usage
+	cmp #$60
+	beq +
+	sec ; mark unsuitable channel number
+	rts
+*
+	clc ; mark suitable channel number
+	rts
diff --git a/c64/kernal/iec/iec_pull_atn_clk_release_data.s b/c64/kernal/iec/iec_pull_atn_clk_release_data.s
new file mode 100644
index 00000000..7d00da80
--- /dev/null
+++ b/c64/kernal/iec/iec_pull_atn_clk_release_data.s
@@ -0,0 +1,15 @@
+
+iec_pull_atn_clk_release_data:
+
+	;; Pulled CLK = DATA considered invalid; for extra robustness on non-emulated
+	;; hardware give some lines few more cycles to stabilize; see page 10 of
+	;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_ATN_OUT          ; pull
+	sta CIA2_PRA
+	ora #BIT_CIA2_PRA_CLK_OUT          ; pull
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_DAT_OUT    ; release
+	sta CIA2_PRA
+	rts
diff --git a/c64/kernal/iec/iec_pull_clk_release_data.s b/c64/kernal/iec/iec_pull_clk_release_data.s
new file mode 100644
index 00000000..38be0f89
--- /dev/null
+++ b/c64/kernal/iec/iec_pull_clk_release_data.s
@@ -0,0 +1,13 @@
+
+iec_pull_clk_release_data:
+
+	;; Pulled CLK = DATA considered invalid; for extra robustness on non-emulated
+	;; hardware give some lines few more cycles to stabilize; see page 10 of
+	;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_CLK_OUT          ; pull
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_DAT_OUT    ; release
+	sta CIA2_PRA
+	rts
diff --git a/c64/kernal/iec/iec_pull_data_release_atn_clk.s b/c64/kernal/iec/iec_pull_data_release_atn_clk.s
new file mode 100644
index 00000000..14e0e236
--- /dev/null
+++ b/c64/kernal/iec/iec_pull_data_release_atn_clk.s
@@ -0,0 +1,15 @@
+
+iec_pull_data_release_atn_clk:
+
+	;; Released CLK = DATA considered valid; for extra robustness on non-emulated
+	;; hardware give some lines few more cycles to stabilize; see page 10 of
+	;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+	
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_DAT_OUT         ; pull
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_CLK_OUT   ; release
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_ATN_OUT   ; release
+	sta CIA2_PRA
+	rts
diff --git a/c64/kernal/iec/iec_release_atn.s b/c64/kernal/iec/iec_release_atn.s
new file mode 100644
index 00000000..2aef8984
--- /dev/null
+++ b/c64/kernal/iec/iec_release_atn.s
@@ -0,0 +1,8 @@
+
+iec_release_atn:
+
+	lda CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_ATN_OUT    ; release
+	sta CIA2_PRA
+	rts
+
diff --git a/c64/kernal/iec/iec_release_atn_clk_data.s b/c64/kernal/iec/iec_release_atn_clk_data.s
new file mode 100644
index 00000000..904ee13f
--- /dev/null
+++ b/c64/kernal/iec/iec_release_atn_clk_data.s
@@ -0,0 +1,16 @@
+
+iec_release_atn_clk_data:
+
+	;; Released CLK = DATA considered valid; for extra robustness on non-emulated
+	;; hardware give some lines few more cycles to stabilize; see page 10 of
+	;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+
+	lda CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_ATN_OUT    ; release
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_DAT_OUT    ; release
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_CLK_OUT    ; release
+	sta CIA2_PRA
+	rts
+
diff --git a/c64/kernal/iec/iec_release_clk_data.s b/c64/kernal/iec/iec_release_clk_data.s
new file mode 100644
index 00000000..f48daa6c
--- /dev/null
+++ b/c64/kernal/iec/iec_release_clk_data.s
@@ -0,0 +1,13 @@
+
+iec_release_clk_data:
+
+	;; Released CLK = DATA considered valid; for extra robustness on non-emulated
+	;; hardware give some lines few more cycles to stabilize; see page 10 of
+	;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+
+	lda CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_DAT_OUT    ; release
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_CLK_OUT    ; release
+	sta CIA2_PRA
+	rts
diff --git a/c64/kernal/iec/iec_release_clk_pull_data.s b/c64/kernal/iec/iec_release_clk_pull_data.s
new file mode 100644
index 00000000..9f252ed3
--- /dev/null
+++ b/c64/kernal/iec/iec_release_clk_pull_data.s
@@ -0,0 +1,13 @@
+
+iec_release_clk_pull_data:
+
+	;; Released CLK = DATA considered valid; for extra robustness on non-emulated
+	;; hardware give some lines few more cycles to stabilize; see page 10 of
+	;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_DAT_OUT          ; pull
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_CLK_OUT    ; release
+	sta CIA2_PRA
+	rts
diff --git a/c64/kernal/iec/iec_return.s b/c64/kernal/iec/iec_return.s
new file mode 100644
index 00000000..a89a1336
--- /dev/null
+++ b/c64/kernal/iec/iec_return.s
@@ -0,0 +1,38 @@
+
+;;
+;; Helper routines to return with error/success
+;;
+;; All of them restore X/Y registers from stack,
+;; they take care about Carry flag,
+;; error return reeset IEC line to default state,
+;; take care about .A and IOSTATUS
+;;
+
+iec_return_success:
+
+	;; BSOUR is certainly not valid anymore
+	lda #$00
+	sta C3PO
+	;; Restore registers
+	pla
+	tay
+	pla
+	tax
+	;; Report success
+	clc
+	rts
+
+iec_return_DEVICE_NOT_FOUND:
+
+	;; Set IEC line to normal idle state
+	jsr iec_set_idle
+	;; BSOUR is certainly not valid anymore
+	lda #$00
+	sta C3PO
+	;; Restore registers
+	pla
+	tay
+	pla
+	tax
+	;; Report error
+	jmp kernalerror_DEVICE_NOT_FOUND
diff --git a/c64/kernal/iec/iec_rx_byte.s b/c64/kernal/iec/iec_rx_byte.s
new file mode 100644
index 00000000..c9a3b501
--- /dev/null
+++ b/c64/kernal/iec/iec_rx_byte.s
@@ -0,0 +1,147 @@
+;; Receive a byte from the IEC bus.
+;; Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc,
+;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf (page 11)
+;;
+;; Preserves .X and .Y registers
+
+iec_rx_byte:
+
+	;; Store .X and .Y on the stack - preserve them
+	txa
+	pha
+	tya
+	pha
+
+	;; Timing is critical here - execute on disabled IRQs
+	php
+	sei
+
+	;; First, we wait for the talker to release the CLK line
+	jsr iec_wait_for_clk_release
+
+	;; We then release the DATA to signal we are ready
+	;; We can use this routine, since we weren't pulling CLK anyway
+	jsr iec_release_clk_data
+
+	;; Wait till data line is released (someone else might be holding it)
+	jsr iec_wait_for_data_release
+
+	;; Wait for talker to pull CLK.
+	;; If over 200 usec (205 cycles on NTSC machine) , then it is EOI.
+	;; Loop iteraction takes 13 cycles, 17 full iterations are enough
+
+	ldx #$11                ; 2 cycles
+iec_rx_clk_wait1:
+	lda CIA2_PRA            ; 4 cycles
+	rol                     ; 2 cycles, to put CLK in as the last bit
+	bpl iec_rx_not_eoi      ; 2 cycles if not jumped
+	dex                     ; 2 cycles
+    bne iec_rx_clk_wait1    ; 3 cycles if jumped
+    
+    ;; Timeout - either this is the last byte of stream, or the stream is empty at all.
+    ;; Mark end of stream in IOSTATUS
+    jsr kernalstatus_EOI
+
+iec_rx_not_empty:
+
+	;; Pull data for 60 usec to confirm it
+	jsr iec_release_clk_pull_data
+	jsr iec_wait60us
+	jsr iec_release_clk_data
+
+iec_rx_not_eoi:
+
+	;; Latch input bits in on rising edge of CLK, eight times for eight bits.
+	ldx #7
+
+	;; Get empty byte to load into.
+	lda #$00
+	pha
+
+iec_rx_bit_loop:
+
+	;; Wait for CLK to release
+	jsr iec_wait_for_clk_release
+
+	;; (we do this implicitly below, with a tighter routine,
+	;; so that we don't have timing problems, as the requirements
+	;; are quite tight. Basically we need to read the clock and data
+	;; bit from the same byte read.
+
+	;; DATA now has the next bit, but inverted (well, except that it turns out not to be).
+	;; DATA is in bit 7, which is a bit annoying.
+	;; But we can clock it out with a ROL instruction
+	;; so that it is in C. We can then ROR it into the
+	;; partial data byte.
+	;; We use ROR so that we shift in from the top, so that
+	;; the first bit we shift in ends up in bit 0 after all
+	;; 8 bits have been read.
+	;; ODD: For some reason we don't need to invert the
+	;; received bits.  This is weird, because we invert them
+	;; on the way out, and everything in the protocol seems
+	;; to indicate that we sould do so.  But experimentation
+	;; has confirmed the bits don't need inversion on reception.
+
+	;; Move data bit into C flag, and loop until bit 6 clears
+	;; i.e., the clock has been released.
+
+*	lda CIA2_PRA
+	rol
+	bpl -
+
+	;; Pull it into the data byte
+	pla
+	ror
+	pha
+
+	;; Wait for CLK to be pulled again, over 300 usec (307 cycles on NTSC)
+	;; consider this a timeout
+	ldy #$19                ; 2 cycles
+iec_rx_clk_wait2:
+	lda CIA2_PRA            ; 4 cycles
+	rol                     ; 2 cycles, to put CLK in as the last bit
+	bpl +                   ; 2 cycles if not jumped
+	dey                     ; 2 cycles
+    bne iec_rx_clk_wait2    ; 3 cycles if jumped
+    
+	;; Timeout
+	jsr kernalstatus_EOI
+	pla
+	plp
+    
+	;; Restore registers
+	pla
+	tay
+	pla
+	tax
+    
+	sec ; XXX confirm that sec is really a way to report timeout here
+	rts
+*
+	;; More bits?
+	dex
+	bpl iec_rx_bit_loop
+
+	;; Then we must within 1000 usec acknowledge the frame by
+	;; pulling DATA. At this point, CLK is pulled by the
+	;; talker and DATA by us, i.e., we are ready to receive
+	;; the next byte. (p11).
+	jsr iec_release_clk_pull_data
+
+	;; Retreive the received byte
+	pla
+
+	;; Return no-error
+	plp
+	
+	;; Restore registers
+	sta IEC_TMP2 ; $A4 is a byte buffer according to http://sta.c64.org/cbm64mem.html
+	pla
+	tay
+	pla
+	tax
+	lda IEC_TMP2
+
+	clc
+	rts
+
diff --git a/c64/kernal/iec/iec_set_idle.s b/c64/kernal/iec/iec_set_idle.s
new file mode 100644
index 00000000..1604306d
--- /dev/null
+++ b/c64/kernal/iec/iec_set_idle.s
@@ -0,0 +1,7 @@
+
+iec_set_idle:
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_CLK_OUT                                 ; pull
+	and #$FF - BIT_CIA2_PRA_DAT_OUT - BIT_CIA2_PRA_ATN_OUT    ; release
+	sta CIA2_PRA
+	rts
diff --git a/c64/kernal/iec/iec_turnaround_to_listen.s b/c64/kernal/iec/iec_turnaround_to_listen.s
new file mode 100644
index 00000000..0e66047a
--- /dev/null
+++ b/c64/kernal/iec/iec_turnaround_to_listen.s
@@ -0,0 +1,38 @@
+	;; 	According to http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+	;;  	pages 7--8.
+	;; See also https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
+
+iec_turnaround_to_listen:
+
+	;; Store .X and .Y on the stack - preserve them
+	txa
+	pha
+	tya
+	pha
+
+	;; Timing is critical here - execute on disabled IRQs
+	php
+	sei
+
+	;; Pull DATA, release CLK and ATN (we are not sending commands)
+	jsr iec_pull_data_release_atn_clk
+
+	;; Wait for clock line to be pulled by the drive
+	ldx #$FF ; XXX should we really use that high number?
+*
+	lda CIA2_PRA
+	rol    ; to put BIT_CIA2_PRA_CLK_IN as the last (sign) bit 
+	bpl +
+	dex
+	bne -
+
+	;; Timeout - XXX what errors do original Kernal report?
+	plp
+	jmp iec_return_DEVICE_NOT_FOUND
+
+	;; CLK is pulled by the device, OK
+*
+	plp
+	jmp iec_return_success
+
+
diff --git a/c64/kernal/iec/iec_turnaround_to_talk.s b/c64/kernal/iec/iec_turnaround_to_talk.s
new file mode 100644
index 00000000..666c89e2
--- /dev/null
+++ b/c64/kernal/iec/iec_turnaround_to_talk.s
@@ -0,0 +1,29 @@
+	;; 	According to http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+	;;  	pages 7--8.
+	;; See also https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
+
+iec_turnaround_to_talk:
+
+	;; Store .X and .Y on the stack - preserve them
+	txa
+	pha
+	tya
+	pha
+
+	;; Timing is critical here - execute on disabled IRQs
+	php
+	sei
+
+	;; First make sure both CLK, DATA and ATN are released at our side
+	jsr iec_release_atn
+	jsr iec_release_clk_data
+
+	;; Wait till device releases CLK line
+	jsr iec_wait_for_clk_release
+
+	;; Pull CLK line, it should be held by talker
+	jsr iec_pull_clk_release_data
+
+	plp
+	jmp iec_return_success
+
diff --git a/c64/kernal/iec/iec_tx_byte.s b/c64/kernal/iec/iec_tx_byte.s
new file mode 100644
index 00000000..767dce76
--- /dev/null
+++ b/c64/kernal/iec/iec_tx_byte.s
@@ -0,0 +1,40 @@
+
+;; Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
+
+;; Expects byte to send in IEC_TMP2 ($A4 is a byte buffer according to http://sta.c64.org/cbm64mem.html)
+;; Carry flag set = signal EOI
+;;
+;; Preserves .X and .Y registers
+
+
+iec_tx_byte:
+
+	;; Store .X and .Y on the stack - preserve them
+	txa
+	pha
+	tya
+	pha
+
+	;; Notify all devices that we are going to send a byte
+	;; and it is going to be a data byte (released ATN)
+	jsr iec_release_atn_clk_data
+
+	;; Common part of iec_txbyte and iec_tx_common - waits for devices
+	;; and transmits a byte
+
+	jsr iec_tx_common
+	
+	;; Give device time to tell if they are busy by pulling DATA
+	;; They should do it within 1ms
+	ldx #$FF
+*	lda CIA2_PRA
+	;; BPL here is checking that bit 7 clears,
+	;; i.e, that the DATA line is pulled by drive
+	bpl +
+	dex
+	bne -
+	bpl iec_return_DEVICE_NOT_FOUND
+*
+	jmp iec_return_success
+
+
diff --git a/c64/kernal/iec/iec_tx_command.s b/c64/kernal/iec/iec_tx_command.s
new file mode 100644
index 00000000..e2da97f2
--- /dev/null
+++ b/c64/kernal/iec/iec_tx_command.s
@@ -0,0 +1,62 @@
+
+;; Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
+
+;; Expects byte to send in IEC_TMP2 ($A4 is a byte buffer according to http://sta.c64.org/cbm64mem.html)
+;; Carry flag set = signal EOI
+;;
+;; Preserves .X and .Y registers
+
+
+iec_tx_command:
+
+	;; Store .X and .Y on the stack - preserve them
+	txa
+	pha
+	tya
+	pha
+
+	;; Notify all devices that we are going to send a byte
+	;; and it is going to be a command (pulled ATN)
+	jsr iec_pull_atn_clk_release_data
+
+	;; Give devices time to respond (response is mandatory!)
+	jsr iec_wait1ms
+
+	;; Did at least one device respond by pulling DATA?
+	lda CIA2_PRA
+	and #BIT_CIA2_PRA_DAT_IN ; XXX try to optimize this, move to separate routine
+	beq +
+
+	;; No devices present on the bus, so we can immediately return with device not found	
+	jmp iec_return_DEVICE_NOT_FOUND
+*
+	;; At least one device responded, but they are still allowed to stall
+	;; (can be busy processing something), we have to wait till they are all
+	;; ready (or bored with DOS attack...)
+	;; Release back CLK, keep DATA released - to ask devices for status.
+
+	jsr iec_release_clk_data
+
+	;; Common part of iec_txbyte and iec_tx_common - waits for devices
+	;; and transmits a byte
+
+	clc ; Carry flag set is used for EOI mark
+	jsr iec_tx_common
+
+	;; According to https://www.pagetable.com/?p=1135 there is some complicated and dangerous
+	;; flow here, but http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf (page 6)
+	;; advices to just wait 1ms and check the DATA status
+	jsr iec_wait1ms
+	lda CIA2_PRA
+	and #BIT_CIA2_PRA_DAT_IN ; XXX try to optimize this, move to separate routine
+	beq +
+
+	;; XXX possible optimization of the flow above: for many commands it is enough
+	;; to wait for the DATA being pulled, as confirmation is expected from
+	;; a single device only - but not sure if it's worth the trouble
+
+	jmp iec_return_DEVICE_NOT_FOUND
+*
+	;; Done
+
+	jmp iec_return_success
diff --git a/c64/kernal/iec/iec_tx_command_finalize.s b/c64/kernal/iec/iec_tx_command_finalize.s
new file mode 100644
index 00000000..e0ad0c35
--- /dev/null
+++ b/c64/kernal/iec/iec_tx_command_finalize.s
@@ -0,0 +1,20 @@
+
+;; Routine to finalize some IEC commands - which do not end in turnaround and are not followed by others
+;; Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
+
+
+iec_tx_command_finalize:
+
+	;; Store .X and .Y on the stack - preserve them
+	txa
+	pha
+	tya
+	pha
+
+	;; Give device some time to complete command reception, release ATN,
+	;; give it some time again before (possible) next command
+	jsr iec_wait20us
+	jsr iec_set_idle
+	jsr iec_wait20us
+
+	jmp iec_return_success
diff --git a/c64/kernal/iec/iec_tx_common.s b/c64/kernal/iec/iec_tx_common.s
new file mode 100644
index 00000000..8cc63e0f
--- /dev/null
+++ b/c64/kernal/iec/iec_tx_common.s
@@ -0,0 +1,72 @@
+
+;; This is a common part of iec_tx_byte and iec_tx_command
+;; Implemented based on https://www.pagetable.com/?p=1135, https://github.com/mist64/cbmbus_doc
+;; and http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+
+;; Expects byte to send in IEC_TMP2 ($A4 is a byte buffer according to http://sta.c64.org/cbm64mem.html)
+;; Carry flag set = signal EOI
+
+iec_tx_common:
+
+	;; Timing is critical here - execute on disabled IRQs
+	php
+	sei
+
+	;; Wait till all receivers are ready, they should all release DATA
+	jsr iec_wait_for_data_release
+
+	;; At this point a delay 256 usec or more is considered EOI - add waits if necessary
+	bcc +
+	jsr iec_wait100us
+	jsr iec_wait100us
+	jsr iec_wait60us
+
+	;; XXX waits above should be enough - why do we need more waits???
+	jsr iec_wait100us
+	jsr iec_wait100us
+	jsr iec_wait100us
+
+	;; Receiver should now acknowledge EOI by pulling data for at least 60 usec
+	jsr iec_wait60us
+	jsr iec_wait_for_data_release
+*
+	;; Pull CLK back to indicate that DATA is not valid, keep it for 60us
+	;; We can use this routine as we don't hold DATA anyway (and its state doesn't even matter)
+
+	jsr iec_pull_clk_release_data
+	jsr iec_wait60us
+	
+	;; Now, we can start transmission of 8 bits of data
+	ldx #7
+
+iec_tx_common_sendbit:
+	;; Is next bit 0 or 1?
+	lda IEC_TMP2
+	lsr
+	sta IEC_TMP2
+	bcs +
+
+	;; Bit is 0
+	jsr iec_release_clk_pull_data
+	jmp iec_tx_common_bit_is_sent
+*
+	;; Bit is 1
+	jsr iec_release_clk_data
+	
+iec_tx_common_bit_is_sent:
+
+	;; Wait 20us, so that device(s) can pick DATA
+	jsr iec_wait20us
+		
+	;; Pull CLK for 20us again, before sending the next bit
+	;; or performing any other action
+	jsr iec_pull_clk_release_data
+	jsr iec_wait20us ; XXX this might be an overkill, there is a lot of code besides this wait here - few NOPs might be enough
+
+	;; More bits to send?
+	dex
+	bpl iec_tx_common_sendbit
+
+	plp
+	rts ; Flow continues differently for data/command
+
diff --git a/c64/kernal/iec/iec_tx_flush.s b/c64/kernal/iec/iec_tx_flush.s
new file mode 100644
index 00000000..95395f77
--- /dev/null
+++ b/c64/kernal/iec/iec_tx_flush.s
@@ -0,0 +1,15 @@
+
+;; Flush the IEC output buffer (if not empty) - send byte with EOI
+;;
+;; Preserves .X, .Y and .A registers
+
+iec_tx_flush:
+
+	pha
+	lda C3PO
+	beq +
+	sec ; send it with EOI
+	jsr iec_tx_byte ; send the command regardless of the status
+*
+	pla
+	rts
diff --git a/c64/kernal/iec/iec_wait100us.s b/c64/kernal/iec/iec_wait100us.s
new file mode 100644
index 00000000..b3101685
--- /dev/null
+++ b/c64/kernal/iec/iec_wait100us.s
@@ -0,0 +1,22 @@
+
+iec_wait100us:	
+
+	;; Wait 100usec
+
+	;; PAL:
+	;; - CPU frequency 0.985248 MHz, we need to waste at least  99 cycles
+	;; NTSC:
+	;; - CPU frequency 1.022727 MHZ, we need to waste at least 103 cycles
+
+	;; Waste cycles in a loop
+
+	ldy #$12   ; 2 cycles
+*	dey        ; 2 cycles * 18
+	bpl -      ; 3 cycles * 17 + 2 cycles
+	rts        ; 6 cycles
+
+	;;   6 cycles JSR to routine, 
+    ;;  97 cycles routine with RTS
+    ;;   1 cycle to fetch next instruction
+    ;; ---
+    ;;  104 cycles
diff --git a/c64/kernal/iec/iec_wait1ms.s b/c64/kernal/iec/iec_wait1ms.s
new file mode 100644
index 00000000..a492df7f
--- /dev/null
+++ b/c64/kernal/iec/iec_wait1ms.s
@@ -0,0 +1,20 @@
+
+;;
+;; Wait 1 ms (1000 usec)
+;;
+;; On NTSC this means 1023 cycles (slightly less on PAL, but we have to be sure).
+;; We can't count on badlines, as the screen might be disabled.
+;; Delay here is implemeented using VIC-II raster register. Since one raster is
+;; 63 cycles, we need at least 17 full rasters to be 100% sure we wait enough
+
+
+iec_wait1ms:
+	ldx #18 ; we probably won't start with the beginning of raster
+	lda VIC_RASTER
+*
+	cmp VIC_RASTER
+	beq -
+	lda VIC_RASTER
+	dex
+	bne -
+	rts
diff --git a/c64/kernal/iec/iec_wait20us.s b/c64/kernal/iec/iec_wait20us.s
new file mode 100644
index 00000000..3ea1349f
--- /dev/null
+++ b/c64/kernal/iec/iec_wait20us.s
@@ -0,0 +1,22 @@
+
+iec_wait20us:
+
+	;; Wait 20usec
+
+	;; PAL:
+	;; - CPU frequency 0.985248 MHz, we need to waste at least 20 cycles
+	;; NTSC:
+	;; - CPU frequency 1.022727 MHZ, we need to waste at least 21 cycles
+
+	;; Waste cycles by reading some unimportant memory location
+	;; in order not to clutter VICE debug logs
+
+	ora $03FF    ; 4 cycles
+	ora $03FF    ; 4 cycles
+	rts          ; 6 cycles
+
+	;;   6 cycles JSR to routine, 
+    ;;  14 cycles routine with RTS
+    ;;   1 cycle to fetch next instruction
+    ;; ---
+    ;;  21 cycles
diff --git a/c64/kernal/iec/iec_wait60us.s b/c64/kernal/iec/iec_wait60us.s
new file mode 100644
index 00000000..0f6cd957
--- /dev/null
+++ b/c64/kernal/iec/iec_wait60us.s
@@ -0,0 +1,23 @@
+
+iec_wait60us:
+
+	;; Wait 60usec
+
+	;; PAL:
+	;; - CPU frequency 0.985248 MHz, we need to waste at least 60 cycles
+	;; NTSC:
+	;; - CPU frequency 1.022727 MHZ, we need to waste at least 62 cycles
+
+	;; Waste cycles in a loop
+
+	ldy #$0A   ; 2 cycles
+*	dey        ; 2 cycles * 10
+	bpl -      ; 3 cycles * 9  + 2 cycles
+	rts        ; 6 cycles
+
+	;;   6 cycles JSR to routine, 
+    ;;  57 cycles routine with RTS
+    ;;   1 cycle to fetch next instruction
+    ;; ---
+    ;;  64 cycles
+
diff --git a/c64/kernal/iec/iec_wait_for_clk_release.s b/c64/kernal/iec/iec_wait_for_clk_release.s
new file mode 100644
index 00000000..22edfdfa
--- /dev/null
+++ b/c64/kernal/iec/iec_wait_for_clk_release.s
@@ -0,0 +1,7 @@
+
+iec_wait_for_clk_release:
+
+	lda CIA2_PRA
+	and #BIT_CIA2_PRA_CLK_IN
+	beq iec_wait_for_clk_release
+	rts
diff --git a/c64/kernal/iec/iec_wait_for_data_pull.s b/c64/kernal/iec/iec_wait_for_data_pull.s
new file mode 100644
index 00000000..93bbabe9
--- /dev/null
+++ b/c64/kernal/iec/iec_wait_for_data_pull.s
@@ -0,0 +1,8 @@
+
+iec_wait_for_data_pull:
+
+	lda CIA2_PRA
+	;; Check the highest bit, which is DATA IN,
+	;; (highest bit set = negative value)
+	bmi iec_wait_for_data_pull
+	rts
diff --git a/c64/kernal/iec/iec_wait_for_data_release.s b/c64/kernal/iec/iec_wait_for_data_release.s
new file mode 100644
index 00000000..dc89638a
--- /dev/null
+++ b/c64/kernal/iec/iec_wait_for_data_release.s
@@ -0,0 +1,8 @@
+
+iec_wait_for_data_release:
+
+	lda CIA2_PRA
+	;; Check the highest bit, which is DATA IN,
+	;; (highest bit set = negative value)
+	bpl iec_wait_for_data_release
+	rts
diff --git a/c64/kernal/iec_assert_atn.s b/c64/kernal/iec_assert_atn.s
deleted file mode 100644
index 57560c3a..00000000
--- a/c64/kernal/iec_assert_atn.s
+++ /dev/null
@@ -1,5 +0,0 @@
-iec_assert_atn:
-	lda $dd00
-	ora #$08
-	sta $dd00
-	rts
diff --git a/c64/kernal/iec_assert_clk_and_data.s b/c64/kernal/iec_assert_clk_and_data.s
deleted file mode 100644
index 7bb1242a..00000000
--- a/c64/kernal/iec_assert_clk_and_data.s
+++ /dev/null
@@ -1,6 +0,0 @@
-iec_assert_clk_and_data:
-	lda $dd00
-	and #$0b
-	ora #$30
-	sta $dd00
-	rts
diff --git a/c64/kernal/iec_assert_clk_release_data.s b/c64/kernal/iec_assert_clk_release_data.s
deleted file mode 100644
index 2a33a4f8..00000000
--- a/c64/kernal/iec_assert_clk_release_data.s
+++ /dev/null
@@ -1,6 +0,0 @@
-iec_assert_clk_release_data:
-	lda $dd00
-	and #$0b
-	ora #$10
-	sta $dd00
-	rts
diff --git a/c64/kernal/iec_assert_data.s b/c64/kernal/iec_assert_data.s
deleted file mode 100644
index 98ef4891..00000000
--- a/c64/kernal/iec_assert_data.s
+++ /dev/null
@@ -1,5 +0,0 @@
-iec_assert_data:
-	lda $dd00
-	ora #$20
-	sta $dd00
-	rts
diff --git a/c64/kernal/iec_release_atn.s b/c64/kernal/iec_release_atn.s
deleted file mode 100644
index 12c63d02..00000000
--- a/c64/kernal/iec_release_atn.s
+++ /dev/null
@@ -1,11 +0,0 @@
-iec_release_atn:
-	lda $dd00
-	and #$f7
-	sta $dd00
-
-	;; Also clear EOI marker
-	lda IOSTATUS
-	and #$bf
-	sta IOSTATUS
-	
-	rts
diff --git a/c64/kernal/iec_release_clk.s b/c64/kernal/iec_release_clk.s
deleted file mode 100644
index a261ee4d..00000000
--- a/c64/kernal/iec_release_clk.s
+++ /dev/null
@@ -1,5 +0,0 @@
-iec_release_clk:
-	lda $dd00
-	and #$2b
-	sta $dd00
-	rts
diff --git a/c64/kernal/iec_release_clk_and_data.s b/c64/kernal/iec_release_clk_and_data.s
deleted file mode 100644
index db554a6e..00000000
--- a/c64/kernal/iec_release_clk_and_data.s
+++ /dev/null
@@ -1,6 +0,0 @@
-iec_release_clk_and_data:	
-
-	lda $DD00
-	and #$0b
-	sta $DD00
-	rts
diff --git a/c64/kernal/iec_rx_byte.s b/c64/kernal/iec_rx_byte.s
deleted file mode 100644
index 9c7f6768..00000000
--- a/c64/kernal/iec_rx_byte.s
+++ /dev/null
@@ -1,114 +0,0 @@
-	;; Receive a byte from the IEC bus.
-	;; reference http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
-	;; page 11.
-
-
-iec_rx_byte:
-
-	;; First, we wait for the talker to release the CLK line.
-	jsr iec_wait_for_clock_release
-
-	;; We then release the data line
-	;; (We can use this routine, since we weren't holding CLK, anyway)
-	jsr iec_release_clk_and_data
-
-	;; Wait for talker to assert CLK.
-	;; If >200usec, then it is EOI and we have to assert the
-	;; DATA line for 60 usec to tell the TALKER that we have
-	;; acknowledged the EOI.
-	ldx #20
-iec_rx_clk_wait:
-	;; Loop takes 11 usec, so ~20 iterations for 200usec timeout
-	lda $dd00
-	rol
-	bpl not_eoi
-	dex
-	cpx #$21
-	bne not_rx_timeout
-	;; Time out waiting for CLK to assert again.
-	;;  = error
-	sec
-	rts
-not_rx_timeout:
-	cpx #$00
-	bpl iec_rx_clk_wait
-
-	;; Remember EOI condition
-	lda IOSTATUS
-	ora #$40
-	sta IOSTATUS
-
-	;; EOI timeout: So pulse DATA line for 60 usec
-	jsr iec_assert_data
-	jsr iec_wait60us
-	jsr iec_release_clk_and_data
-
-	;; And still wait for CLK to be asserted
-	;; XXX - This will cause periodic EOI pulses if the sender takes too long.
-	;; That is probably ok.
-	ldx #$7f
-	jmp iec_rx_clk_wait
-
-not_eoi:
-	;; CLK is now low.  Latch input bits in on rising edge
-	;; of CLK, eight times for eight bits.
-	ldx #7
-
-	;; Get empty byte to load into.
-	lda #$00
-	pha
-	
-iec_rx_bit_loop:
-
-	;; Wait for CLK to release
-	;; jsr iec_wait_for_clock_release
-	;; (we do this implicitly below, with a tighter routine,
-	;; so that we don't have timing problems, as the requirements
-	;; are quite tight. Basically we need to read the clock and data
-	;; bit from the same byte read.
-
-	;; DATA now has the next bit, but inverted (well, except that it turns out not to be).
-	;; DATA is in bit7, which is a bit annoying.
-	;; But we can clock it out with a ROL instruction
-	;; so that it is in C. We can then ROR it into the
-	;; partial data byte.
-	;; We use ROR so that we shift in from the top, so that
-	;; the first bit we shift in ends up in bit 0 after all
-	;; 8 bits have been read.
-	;; ODD: For some reason we don't need to invert the
-	;; received bits.  This is weird, because we invert them
-	;; on the way out, and everything in the protocol seems
-	;; to indicate that we sould do so.  But experimentation
-	;; has confirmed the bits don't need inversion on reception.
-	
-	;; Move data bit into C flag, and loop until bit 6 clears
-	;; i.e., the clock has been released.
-*	LDA $DD00
-	ROL
-	bpl -
-	
-	;; Pull it into the data byte
-	pla
-	ROR
-	pha
-
-	;; Wait for CLK to re-assert
-	jsr iec_wait_for_clock_assert
-
-	;; More bits?
-	dex
-	bpl iec_rx_bit_loop
-
-	;; Then we must within 1000usec acknowledge the frame by
-	;; asserting DATA. At this point, CLK is asserted by the
-	;; talker and DATA by us, i.e., we are ready to receive
-	;; the next byte. (p11).
-	jsr iec_assert_data
-
-	;; Retreive the received byte
-	PLA
-
-	;; Return no-error
-	CLC
-	RTS
-	
diff --git a/c64/kernal/iec_turnaround_to_listen.s b/c64/kernal/iec_turnaround_to_listen.s
deleted file mode 100644
index b65565b7..00000000
--- a/c64/kernal/iec_turnaround_to_listen.s
+++ /dev/null
@@ -1,39 +0,0 @@
-	;; 	According to http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
-	;;  	pages 7--8.
-	
-iec_turnaround_to_listen:
-
-	;; Assert data and release clock
-	lda $dd00
-	and #$ef		; release clock (bit 4)
-	ora #$20     		; assert data (bit 5)
-	sta $dd00
-	
-	;; Wait for clock line to be asserted by the drive
-*	lda $dd00
-	and #$40
-	bne -
-
-	;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
-	;; page 8 tells us we should not do anything here after waiting for
-	;; the clock line to assert.
-	
- 	ldx #$ff
- *	lda $dd00
- 	and #$40
- 	bne +
- 	dex
- 	bne -
-
-	 ;; jsr printf
-	 ;; .byte "TURNAROUND FAILED - FILE NOT FOUND?",$0d,$00
-	
-	;; ;; Timeout = file not found error
-	;; ;; (https://www.pagetable.com/?p=1023)
-	 lda #4
-	 sec
-	 rts
-*
-	;; ATN turn around successful
-	clc
-	rts
diff --git a/c64/kernal/iec_tx_byte.s b/c64/kernal/iec_tx_byte.s
deleted file mode 100644
index 03f35c6d..00000000
--- a/c64/kernal/iec_tx_byte.s
+++ /dev/null
@@ -1,87 +0,0 @@
-iec_tx_byte:	
-
-	pha
-
-	jsr iec_assert_clk_release_data
-
-	;; Give devices time to respond
-	jsr wait1ms
-
-	;; Did a device respond? (DATA will be pulled if so)
-	lda $DD00
-	bpl +
-
-	;; No devices present, so we can immediately return with device not found
-	pla
-	jmp kernalerror_DEVICE_NOT_FOUND
-*
-
-	;; Release CLK and wait for DATA to release.
-	jsr iec_release_clk_and_data
-	
-	;; Wait for DATA to be released
-	;; Listener is allowed to hold DATA for as long as they want.
-	;; i.e., this is the part of the protocol where the listener indicates
-	;; that they are busy doing something, like processing the previous
-	;; character.
-	jsr iec_wait_for_data_release
-
-	;; We then wait for 60 usec (less than 200usec so we don't
-	;; signal EOI), before asserting CLK again.
-	jsr iec_wait60us
-
-	;; Do the actual transmission of 8 bits of data
-	ldx #7
-
-	pla
-	
-iec_tx_byte_nextbit:	
-	;; Is next bit 0 or 1?
-	lsr
-	pha
-	bcs +
-	
-	;; Setup 0
-	jsr iec_assert_clk_and_data
-	jmp iec_tx_byte_l1
-*
-	;; Setup 1
-	jsr iec_assert_clk_release_data
-iec_tx_byte_l1:
-	;; Clock bit out
-	jsr iec_wait20us
-
-	jsr iec_release_clk
-
-	jsr iec_wait20us
-
-	;; More bits to send?
-	pla
-	dex
-	bpl iec_tx_byte_nextbit
-
-	;; Done sending bits. Assert CLK and wait for acknowledgement
-	jsr iec_assert_clk_release_data
-
-	;; Acknowledgement must happen within 1ms, else it
-	;; is DEVICE NOT PRESENT
-	;; Acknowledgement consists of the DATA line being pulled
-	;; by the listener.
-	;; We can't easily count rasters here, so we just
-	;; try a set number of times
-	ldx #$ff
-*	lda $DD00
-	;; BPL here is checking that bit 7 of $DD00 clears,
-	;; i.e, that the DATA line is asserted.
-	bpl +
-	dex
-	bne -
-
-	;; Timeout - DEVICE NOT PRESENT
-	jmp kernalerror_DEVICE_NOT_FOUND
-*
-	;; All done.
-	;; End state is TALKER is asserting CLK, and listener is asserting DATA
-	;; until they are ready for the next byte.
-	clc
-	rts
diff --git a/c64/kernal/iec_wait20us.s b/c64/kernal/iec_wait20us.s
deleted file mode 100644
index 86456409..00000000
--- a/c64/kernal/iec_wait20us.s
+++ /dev/null
@@ -1,7 +0,0 @@
-
-iec_wait20us:	
-	;; Wait 20usec
-	;; JSR + RTS already costs 12, so need only 8 more
-	ldy $dd00
-	ldy $dd00
-	rts
diff --git a/c64/kernal/iec_wait60us.s b/c64/kernal/iec_wait60us.s
deleted file mode 100644
index d1eed334..00000000
--- a/c64/kernal/iec_wait60us.s
+++ /dev/null
@@ -1,9 +0,0 @@
-iec_wait60us:	
-
-	;; Waste ~60 clock cycles (including JSR + RTS)
-	ldy #$06
-*	lda $dd00
-	dey
-	bpl -
-
-	rts
diff --git a/c64/kernal/iec_wait_for_clock_assert.s b/c64/kernal/iec_wait_for_clock_assert.s
deleted file mode 100644
index aa661af9..00000000
--- a/c64/kernal/iec_wait_for_clock_assert.s
+++ /dev/null
@@ -1,5 +0,0 @@
-iec_wait_for_clock_assert:
-	LDA $DD00
-	and #$40
-	bne iec_wait_for_clock_assert
-	rts
diff --git a/c64/kernal/iec_wait_for_clock_release.s b/c64/kernal/iec_wait_for_clock_release.s
deleted file mode 100644
index cb5d8c72..00000000
--- a/c64/kernal/iec_wait_for_clock_release.s
+++ /dev/null
@@ -1,5 +0,0 @@
-iec_wait_for_clock_release:
-	LDA $DD00
-	and #$40
-	beq iec_wait_for_clock_release
-	rts
diff --git a/c64/kernal/iec_wait_for_data_release.s b/c64/kernal/iec_wait_for_data_release.s
deleted file mode 100644
index 36232975..00000000
--- a/c64/kernal/iec_wait_for_data_release.s
+++ /dev/null
@@ -1,5 +0,0 @@
-iec_wait_for_data_release:
-	LDA $DD00
-	and #$40
-	beq iec_wait_for_data_release
-	rts
diff --git a/c64/kernal/irq_handler.s b/c64/kernal/irq_handler.s
index 1b8b4730..82bbaac7 100644
--- a/c64/kernal/irq_handler.s
+++ b/c64/kernal/irq_handler.s
@@ -6,7 +6,7 @@ irq_handler:
 	;; $EA61 - Check keyboard, but don't update timer? https://github.com/cc65/cc65/issues/324
 	;; $EA81 - https://www.lemon64.com/forum/viewtopic.php?t=2112&sid=6ea01982b26da69783120a7923ca46fb
 	;; Also the $0314 vector is widely used (e.g., https://www.lemon64.com/forum/viewtopic.php?t=2112&sid=6ea01982b26da69783120a7923ca46fb)
-	
+
 	;; Save registers
 	;; Sequence according to Compute's Mapping the 64 p73
 	pha
@@ -17,7 +17,7 @@ irq_handler:
 
 	;; Call interrupt routine
 	;; (but only if initialised)
-	lda $0314
-	ora $0315
+	lda CINV
+	ora CINV+1
 	beq default_irq_handler
-	jmp ($0314)
+	jmp (CINV)
diff --git a/c64/kernal/ff81.s b/c64/kernal/jumptable/ff81.jcint.s
similarity index 100%
rename from c64/kernal/ff81.s
rename to c64/kernal/jumptable/ff81.jcint.s
diff --git a/c64/kernal/ff84.s b/c64/kernal/jumptable/ff84.jioinit.s
similarity index 100%
rename from c64/kernal/ff84.s
rename to c64/kernal/jumptable/ff84.jioinit.s
diff --git a/c64/kernal/ff87.s b/c64/kernal/jumptable/ff87.jramtas.s
similarity index 100%
rename from c64/kernal/ff87.s
rename to c64/kernal/jumptable/ff87.jramtas.s
diff --git a/c64/kernal/ff8a.s b/c64/kernal/jumptable/ff8a.jrestor.s
similarity index 100%
rename from c64/kernal/ff8a.s
rename to c64/kernal/jumptable/ff8a.jrestor.s
diff --git a/c64/kernal/ff8d.s b/c64/kernal/jumptable/ff8d.jvector.s
similarity index 100%
rename from c64/kernal/ff8d.s
rename to c64/kernal/jumptable/ff8d.jvector.s
diff --git a/c64/kernal/ff90.s b/c64/kernal/jumptable/ff90.jsetmsg.s
similarity index 100%
rename from c64/kernal/ff90.s
rename to c64/kernal/jumptable/ff90.jsetmsg.s
diff --git a/c64/kernal/ff93.s b/c64/kernal/jumptable/ff93.jsecond.s
similarity index 100%
rename from c64/kernal/ff93.s
rename to c64/kernal/jumptable/ff93.jsecond.s
diff --git a/c64/kernal/ff96.s b/c64/kernal/jumptable/ff96.jtksa.s
similarity index 100%
rename from c64/kernal/ff96.s
rename to c64/kernal/jumptable/ff96.jtksa.s
diff --git a/c64/kernal/ff99.s b/c64/kernal/jumptable/ff99.jmemtop.s
similarity index 100%
rename from c64/kernal/ff99.s
rename to c64/kernal/jumptable/ff99.jmemtop.s
diff --git a/c64/kernal/ff9c.s b/c64/kernal/jumptable/ff9c.jmembot.s
similarity index 100%
rename from c64/kernal/ff9c.s
rename to c64/kernal/jumptable/ff9c.jmembot.s
diff --git a/c64/kernal/ff9f.s b/c64/kernal/jumptable/ff9f.jscnkey.s
similarity index 100%
rename from c64/kernal/ff9f.s
rename to c64/kernal/jumptable/ff9f.jscnkey.s
diff --git a/c64/kernal/ffa2.s b/c64/kernal/jumptable/ffa2.jsettmo.s
similarity index 100%
rename from c64/kernal/ffa2.s
rename to c64/kernal/jumptable/ffa2.jsettmo.s
diff --git a/c64/kernal/ffa5.s b/c64/kernal/jumptable/ffa5.jacptr.s
similarity index 100%
rename from c64/kernal/ffa5.s
rename to c64/kernal/jumptable/ffa5.jacptr.s
diff --git a/c64/kernal/ffa8.s b/c64/kernal/jumptable/ffa8.jciout.s
similarity index 100%
rename from c64/kernal/ffa8.s
rename to c64/kernal/jumptable/ffa8.jciout.s
diff --git a/c64/kernal/ffab.s b/c64/kernal/jumptable/ffab.juntlk.s
similarity index 100%
rename from c64/kernal/ffab.s
rename to c64/kernal/jumptable/ffab.juntlk.s
diff --git a/c64/kernal/ffae.s b/c64/kernal/jumptable/ffae.junlsn.s
similarity index 100%
rename from c64/kernal/ffae.s
rename to c64/kernal/jumptable/ffae.junlsn.s
diff --git a/c64/kernal/ffb1.s b/c64/kernal/jumptable/ffb1.jlisten.s
similarity index 100%
rename from c64/kernal/ffb1.s
rename to c64/kernal/jumptable/ffb1.jlisten.s
diff --git a/c64/kernal/ffb4.s b/c64/kernal/jumptable/ffb4.jtalk.s
similarity index 100%
rename from c64/kernal/ffb4.s
rename to c64/kernal/jumptable/ffb4.jtalk.s
diff --git a/c64/kernal/ffb7.s b/c64/kernal/jumptable/ffb7.jreadst.s
similarity index 100%
rename from c64/kernal/ffb7.s
rename to c64/kernal/jumptable/ffb7.jreadst.s
diff --git a/c64/kernal/ffba.s b/c64/kernal/jumptable/ffba.jsetfls.s
similarity index 87%
rename from c64/kernal/ffba.s
rename to c64/kernal/jumptable/ffba.jsetfls.s
index 4e68df53..6ad1fe44 100644
--- a/c64/kernal/ffba.s
+++ b/c64/kernal/jumptable/ffba.jsetfls.s
@@ -1,3 +1,3 @@
 ; Set logical, first and second addresses
 ; C64 Programmer's Reference Guide Page 273
-	jmp setlfs
+	jmp setfls
diff --git a/c64/kernal/ffbd.s b/c64/kernal/jumptable/ffbd.jsetnam.s
similarity index 100%
rename from c64/kernal/ffbd.s
rename to c64/kernal/jumptable/ffbd.jsetnam.s
diff --git a/c64/kernal/ffc0.s b/c64/kernal/jumptable/ffc0.jopen.s
similarity index 100%
rename from c64/kernal/ffc0.s
rename to c64/kernal/jumptable/ffc0.jopen.s
diff --git a/c64/kernal/ffc3.s b/c64/kernal/jumptable/ffc3.jclose.s
similarity index 100%
rename from c64/kernal/ffc3.s
rename to c64/kernal/jumptable/ffc3.jclose.s
diff --git a/c64/kernal/ffc6.s b/c64/kernal/jumptable/ffc6.jchkin.s
similarity index 100%
rename from c64/kernal/ffc6.s
rename to c64/kernal/jumptable/ffc6.jchkin.s
diff --git a/c64/kernal/ffc9.s b/c64/kernal/jumptable/ffc9.jckout.s
similarity index 85%
rename from c64/kernal/ffc9.s
rename to c64/kernal/jumptable/ffc9.jckout.s
index 1b76a8dc..ccfe9a2f 100644
--- a/c64/kernal/ffc9.s
+++ b/c64/kernal/jumptable/ffc9.jckout.s
@@ -1,3 +1,3 @@
 ; Open channel for output
 ; C64 Programmer's Reference Guide Page 272
-	jmp chkout
+	jmp ckout
diff --git a/c64/kernal/ffcc.s b/c64/kernal/jumptable/ffcc.jclrchn.s
similarity index 100%
rename from c64/kernal/ffcc.s
rename to c64/kernal/jumptable/ffcc.jclrchn.s
diff --git a/c64/kernal/ffcf.s b/c64/kernal/jumptable/ffcf.jchrin.s
similarity index 100%
rename from c64/kernal/ffcf.s
rename to c64/kernal/jumptable/ffcf.jchrin.s
diff --git a/c64/kernal/ffd2.s b/c64/kernal/jumptable/ffd2.jchrout.s
similarity index 100%
rename from c64/kernal/ffd2.s
rename to c64/kernal/jumptable/ffd2.jchrout.s
diff --git a/c64/kernal/ffd5.s b/c64/kernal/jumptable/ffd5.jload.s
similarity index 100%
rename from c64/kernal/ffd5.s
rename to c64/kernal/jumptable/ffd5.jload.s
diff --git a/c64/kernal/ffd8.s b/c64/kernal/jumptable/ffd8.jsave.s
similarity index 100%
rename from c64/kernal/ffd8.s
rename to c64/kernal/jumptable/ffd8.jsave.s
diff --git a/c64/kernal/ffdb.s b/c64/kernal/jumptable/ffdb.jsettim.s
similarity index 100%
rename from c64/kernal/ffdb.s
rename to c64/kernal/jumptable/ffdb.jsettim.s
diff --git a/c64/kernal/ffde.s b/c64/kernal/jumptable/ffde.jrdtim.s
similarity index 100%
rename from c64/kernal/ffde.s
rename to c64/kernal/jumptable/ffde.jrdtim.s
diff --git a/c64/kernal/ffe1.s b/c64/kernal/jumptable/ffe1.jstop.s
similarity index 100%
rename from c64/kernal/ffe1.s
rename to c64/kernal/jumptable/ffe1.jstop.s
diff --git a/c64/kernal/ffe4.s b/c64/kernal/jumptable/ffe4.jgetin.s
similarity index 100%
rename from c64/kernal/ffe4.s
rename to c64/kernal/jumptable/ffe4.jgetin.s
diff --git a/c64/kernal/ffe7.s b/c64/kernal/jumptable/ffe7.jclall.s
similarity index 81%
rename from c64/kernal/ffe7.s
rename to c64/kernal/jumptable/ffe7.jclall.s
index d333af55..03e1725f 100644
--- a/c64/kernal/ffe7.s
+++ b/c64/kernal/jumptable/ffe7.jclall.s
@@ -1,3 +1,3 @@
 ; $FFE7 - Close all files vector
 ; (http://codebase64.org/doku.php?id=base:kernalreference)
-	jmp close_all_files
+	jmp clall
diff --git a/c64/kernal/ffea.s b/c64/kernal/jumptable/ffea.judtim.s
similarity index 100%
rename from c64/kernal/ffea.s
rename to c64/kernal/jumptable/ffea.judtim.s
diff --git a/c64/kernal/ffed.s b/c64/kernal/jumptable/ffed.jscreen.s
similarity index 83%
rename from c64/kernal/ffed.s
rename to c64/kernal/jumptable/ffed.jscreen.s
index a9e258cf..55d44e37 100644
--- a/c64/kernal/ffed.s
+++ b/c64/kernal/jumptable/ffed.jscreen.s
@@ -1,4 +1,4 @@
 ; $FFED - Return screen size (X=columns, Y=rows)
 ; (http://codebase64.org/doku.php?id=base:kernalreference)
 
-	jmp get_screen_size
+	jmp screen
diff --git a/c64/kernal/fff0.s b/c64/kernal/jumptable/fff0.jplot.s
similarity index 100%
rename from c64/kernal/fff0.s
rename to c64/kernal/jumptable/fff0.jplot.s
diff --git a/c64/kernal/jumptable/fff3.jiobase.s b/c64/kernal/jumptable/fff3.jiobase.s
new file mode 100644
index 00000000..1c459c5d
--- /dev/null
+++ b/c64/kernal/jumptable/fff3.jiobase.s
@@ -0,0 +1,19 @@
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 284
+;; - [CM64] Compute's Mapping the Commodore 64 - page 214
+;; - http://codebase64.org/doku.php?id=base:kernalreference (original source)
+;;
+;; CPU registers that has to be preserved (see [RG64]): .A
+;;
+
+
+;; As there is nothing between here and $FFFA, we can just hard code this in place.
+
+iobase:
+    ldy #$DC
+    ldx #$00
+    rts
+
diff --git a/c64/kernal/listen.s b/c64/kernal/listen.s
index 4fc90f42..dd240070 100644
--- a/c64/kernal/listen.s
+++ b/c64/kernal/listen.s
@@ -1,3 +1,30 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 285
+;; - [CM64] Compute's Mapping the Commodore 64 - page 223
+;; - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc
+;; - http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+;;
+;; CPU registers that has to be preserved (see [RG64]): .X, .Y
+;;
+
+
 listen:
-	rts
+
+	;; According to serial-bus.pdf (page 15) this routine flushes the IEC out buffer
+	jsr iec_tx_flush
+
+	;; Check whether device number is correct
+	jsr iec_check_devnum
+	bcc +
+	jmp kernalerror_DEVICE_NOT_FOUND
+*
+	;; Encode and execute the command
+	ora #$20
+
+	jmp common_talk_listen
+
+
+
diff --git a/c64/kernal/load.s b/c64/kernal/load.s
index 4a2ca7c8..e845b546 100644
--- a/c64/kernal/load.s
+++ b/c64/kernal/load.s
@@ -1,7 +1,15 @@
-				; Function defined on pp272-273 of C64 Programmers Reference Guide
-	;; IEC reference at http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
 
-	;; Definition of function from Compute's Mapping the 64 p231
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 286
+;; - [CM64] Compute's Mapping the Commodore 64 - page 231
+;; - IEC reference at http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
+
 	;; Expects that SETLFS and SETNAM are called before hand.
 	;; $YYXX = load address.
 	;; (ignored if SETLFS channel = 1, i.e., like ,8,1)
@@ -9,212 +17,127 @@
 	;; On exit, $YYXX is the highest address into which data
 	;; will have been placed.
 
-	;; Searching through Compute's Mapping the 64, we find the following
-	;; things are used:
-	;; $93 = kernal_load_or_verify_flag
-	;; $AC = current pointer for loading/verifying
-	;; $C1 = similar to the above.
+	;; XXX honor MSGFLG bit 6
+	;; XXX add VERIFY support
+
 load:
 
 	;; Are we loading or verifying?
-	sta kernal_load_or_verify_flag
+	sta VERCK
 
 	;; Store start address of LOAD
-	stx load_save_start_ptr+0
-	sty load_save_start_ptr+1
+	stx STAL+0
+	sty STAL+1
+
+	;; Reset status
+	jsr kernalstatus_reset
 
 	;; We need our helpers to get to filenames under ROMs or IO area
 	jsr install_ram_routines
-	
-	;; Disable IRQs, since timing matters!
-	SEI
 
-	;; Display SEARCHING FOR
-	jsr printf
-	.byte "SEARCHING FOR ",0
+	;; Allow platform-specific routine to takeover the flow
+	`TARGET_HOOK_LOAD
 
-	ldy #$00
-print_filename_loop:	
-	cpy current_filename_length
-	beq +
-	ldx #<current_filename_ptr
-	jsr peek_under_roms
-	jsr $ffd2
-	iny
-	jmp print_filename_loop
-*
-	
-	lda #$0d
-	jsr $ffd2
+	;; Check whether we support the requested device
+	lda current_device_number
+	and #$FC
+	beq lvs_illegal_device_number ; device number below 4, not an IEC device
 
-	;; Begin sending under attention
-	jsr iec_assert_atn
+	;; Device numbers above 30 are also illegal (see https://www.pagetable.com/?p=1031),
+	;; as the protocol combines device number with command code int one byte,
+	;; above 30 it is no longer possible (UNLISTEN and UNTALK codes prevent using
+	;; number 31), yet original ROMs show ILLEGAL DEVICE NUMBER error only
+	;; for devices 0-3; in our implementation LISTEN / TALK will cause device
+	;; not present detected for numbers above 30
+
+	;; Display SEARCHING FOR + filename
+	jsr lvs_display_searching_for
 
-	;; XXX - Use default device number
 	;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
-	;; p13, 16.
-	;; also p16 tells us this routine doesn't mess with the file table in the C64,
-	;; only in the drive.
-	
-	;; Begin sending under attention
-	jsr iec_assert_atn
+	;; p13, 16; also p16 tells us this routine doesn't mess with the file table
+	;; in the C64, only in the drive.
 
-	;; XXX - Use default device number
-	;; http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
-	;; p13, 16.
-	;; also p16 tells us this routine doesn't mess with the file table in the C64,
-	;; only in the drive.
-	
 	;; Call device to LISTEN (p16)
-	lda #$28
-	jsr iec_tx_byte
-	bcs load_error
+	lda current_device_number
+	jsr listen
+	bcs lvs_device_not_found_error
 
-	;; Open channel #0 (p16)
-	lda #$f0
-	jsr iec_tx_byte
-	bcs load_error
+	;; Open channel 0 (reserved for file reading)
+	lda #$00
+	jsr iec_cmd_open
+	bcs lvs_load_verify_error
 
-	;; (p16)
-	jsr iec_release_atn
-
-	;; Send filename (p16)
-	ldy #0
-
-send_filename:
-	cpy current_filename_length
-	beq sent_filename
-	
-	ldx #<current_filename_ptr
-	jsr peek_under_roms
-
-	;; Save Y because iec_tx_byte will corrupt it
-	tax
-	tya
-	pha
-	txa
-
-	jsr iec_tx_byte
-
-	pla
-	tay
-	iny
-	jmp send_filename
-
-sent_filename:	
-	;; Command device to unlisten to indicate end of file name. (p16)
-	jsr iec_assert_atn
-	lda #$3f
-	jsr iec_tx_byte
-	bcs load_error
-	jsr iec_release_atn
+	;; Send file name
+	jsr lvs_send_file_name
+	bcs lvs_load_verify_error
 
 	;; Now command device to talk (p16)
-	jsr iec_assert_atn
-	lda #$48
-	jsr iec_tx_byte
-	bcs load_error
+	lda current_device_number
+	jsr talk
+	bcs lvs_load_verify_error
 
 	lda #$60 ; open channel / data (p3) , required according to p13
-	jsr iec_tx_byte
-	bcs load_error
-	jsr iec_release_atn
+	sta IEC_TMP2
+	jsr iec_tx_command
+	bcs lvs_load_verify_error
 
 	;; We are currently talker, so do the IEC turn around so that we
 	;; are the listener (p16)
-	;; An error here means FILE NOT FOUND ?
 	jsr iec_turnaround_to_listen
-	bcs load_error
+	bcs lvs_load_verify_error
 
 	;; Get load address and store it if secondary address is zero
 	jsr iec_rx_byte
-	bcs file_not_found_error
+	bcs lvs_file_not_found_error
 	ldx current_secondary_address
 	beq +
-	sta load_save_start_ptr+0
+	sta STAL+0
 *
 	jsr iec_rx_byte
-	bcs file_not_found_error
+	bcs lvs_file_not_found_error
 	ldx current_secondary_address
 	beq +
-	sta load_save_start_ptr+1
+	sta STAL+1
 *
-
-	jsr printf
-	.byte "LOADING",$0d,0
+	;; Display start address
+	jsr lvs_display_loading_verifying
 
 load_loop:
 	;; We are now ready to receive bytes
 	jsr iec_rx_byte
-	bcs load_error
+	bcs lvs_load_verify_error
 
-	;; Save it and advance pointer.
-	;; As with our BASIC, we want to enable LOADing
-	;; anywhere in memory, including over the IO space.
-	;; Thus we have to use a helper routine in low memory
-	;; to do the memory access
+	;; Handle the byte (store in memory / verify)
+	jsr lvs_handle_byte_load_verify
+	bcs lvs_load_verify_error
+	
+	;; Advance pointer to data
+	jsr lvs_advance_pointer
+	bcs lvs_wrap_around_error
 
-	;; Save byte under ROMs and IO if required
-	ldx #$33
-	stx $01
-	ldy #0
-	sta (load_save_start_ptr),y
-	ldx #$37
-	stx $01
-
-	;; Advance pointer
-	inc load_save_start_ptr
-	bne +
-	inc load_save_start_ptr+1
-	;; If we wrap around to $0000, then this is bad.
-	beq load_error	
-*
-	;; Check for EOI -- if so, read one last byte
+	;; Check for EOI - if so, this was the last byte
 	lda IOSTATUS
-	and #$40
+	and #K_STS_EOI
 	beq load_loop
 
-load_done:
+	;; Display end address
+	jsr lvs_display_done
+
 	;; Close file on drive
 
 	;; Command drive to stop talking and to close the file
-	jsr iec_assert_atn
-	lda #$5f
-	jsr iec_tx_byte
-	lda #$28
-	jsr iec_tx_byte
-	lda #$e0
-	jsr iec_tx_byte
+	jsr untlk
+
+	lda current_device_number
+	jsr listen
+
+	lda #$E0
+	sta IEC_TMP2
+	jsr iec_tx_command
+	jsr iec_tx_command_finalize
+
 	;; Tell drive to unlisten
-	lda #$3f
-	jsr iec_tx_byte
-	jsr iec_release_atn
+	jsr unlsn
 
-	;; Return last address written to +1
-	;; (Even though Compute's Mapping the 64 says without the +1.
-	;; I'm suspicious. Will have to check behavour on an original C64)
-	ldx load_save_start_ptr+0
-	ldy load_save_start_ptr+1
-
-	clc
-	cli
-	rts
-	
-load_error:
-
-	;; XXX - Indicate KERNAL (not BASIC) LOAD error condtion
-	sec
-	lda #28
-	
-	;; Re-enable interrupts and return
-	cli
-	;; (iec_tx_byte will have set/cleared C flag and put result code
-	;; in A if it was an error).
-	rts
-
-file_not_found_error:
-	;; Indicate KERNAL error condition for file not found
-	sec
-	lda #$04
-	cli
-	rts
+	;; Return last address
+	jmp lvs_return_last_address
diff --git a/c64/kernal/lvs_helpers.s b/c64/kernal/lvs_helpers.s
new file mode 100644
index 00000000..646a9bbd
--- /dev/null
+++ b/c64/kernal/lvs_helpers.s
@@ -0,0 +1,157 @@
+
+;;
+;; Helper functions for various LOAD/VERIVY/SAVE routine variants (IEC / U64 / etc.)
+;;
+
+lvs_send_file_name:
+	ldy #0
+lvs_send_file_name_loop:
+	cpy FNLEN
+	beq lvs_send_file_name_done
+	ldx #<current_filename_ptr
+	jsr peek_under_roms
+	iny
+	;; Set Carry flag on the last file name character, to mark EOI
+	cpy FNLEN
+	clc
+	bne +
+	sec
+*
+	;; Transmit one character
+	sta IEC_TMP2
+	jsr iec_tx_byte
+	jmp lvs_send_file_name_loop
+lvs_send_file_name_done:
+	jsr unlsn
+	rts
+
+lvs_handle_byte_load_verify:
+
+	;; XXX add VERIFY support
+
+	;; Save it and advance pointer.
+	;; As with our BASIC, we want to enable LOADing
+	;; anywhere in memory, including over the IO space.
+	;; Thus we have to use a helper routine in low memory
+	;; to do the memory access
+
+	;; Save byte under ROMs and IO if required
+	php
+	sei
+	;; XXX behavior should depend on address
+	ldx #$33
+	stx $01
+	ldy #0
+	sta (STAL),y
+	ldx #$37
+	stx $01
+	plp
+	rts
+
+lvs_advance_pointer:
+	;; Advance pointer
+	inc STAL
+	bne lvs_success_end
+	inc STAL+1
+	;; If we wrap around to $0000, then this is bad.
+	beq lvs_error_end
+*
+	clc
+	rts
+
+lvs_display_searching_for:
+	lda MSGFLG
+	bpl lvs_display_end
+	jsr printf
+	.byte $0D,"SEARCHING FOR ",0
+	ldy #$00
+*
+	cpy FNLEN
+	beq lvs_display_end
+	ldx #<current_filename_ptr
+	jsr peek_under_roms
+	jsr JCHROUT
+	iny
+	jmp -
+
+lvs_display_end:
+	rts
+
+lvs_display_loading_verifying:
+	;; Display LOADING / VERIFYING and start address
+	lda MSGFLG
+	bpl lvs_display_end
+	lda VERCK
+	beq +
+	jsr printf
+	.byte $0D,"VERIFYING",0
+	jmp lvs_display_start_addr
+*
+	jsr printf
+	.byte $0D,"LOADING",0
+	;; FALLTHROUGH
+	
+lvs_display_start_addr:
+	jsr printf
+	.byte " FROM $",0
+	lda STAL+1
+	jsr printf_printhexbyte
+	lda STAL+0
+	jmp printf_printhexbyte
+
+lvs_display_done:
+	;; Display end address
+	lda MSGFLG
+	bpl lvs_display_end
+	jsr printf
+	.byte " TO $",0
+	lda STAL+1
+	jsr printf_printhexbyte
+	lda STAL+0
+	jsr printf_printhexbyte
+	lda #$0D
+	jmp JCHROUT
+
+lvs_wrap_around_error:
+	;; This error is probably not even detected by C64 Kernal;
+	;; report BASIC error code that looks the most sane
+	lda #B_ERR_OVERFLOW
+lvs_error_end:
+	sec
+	rts
+
+lvs_return_last_address:
+	;; Return last address - Compute's Mapping the 64 says without the '+1',
+	;; checked (short test program) on original ROMs that this is really the case
+	ldx STAL+0
+	ldy STAL+1
+	;; FALLTHROUGH
+
+lvs_success_end:
+	clc
+	rts
+
+lvs_device_not_found_error:
+
+	jsr kernalstatus_DEVICE_NOT_FOUND
+	jmp kernalerror_DEVICE_NOT_FOUND
+
+lvs_illegal_device_number:
+
+	jsr kernalstatus_DEVICE_NOT_FOUND
+	jmp kernalerror_ILLEGAL_DEVICE_NUMBER
+
+.alias lvs_file_not_found_error kernalerror_FILE_NOT_FOUND
+
+lvs_load_verify_error:
+	;; XXX should we really return BASIC error code here?
+	lda VERCK
+	beq lvs_verify_error
+	lda #B_ERR_LOAD
+	bne lvs_error_end
+	;; FALLTHROUGH
+
+lvs_verify_error:
+	lda #B_ERR_VERIFY
+	sec
+	rts
diff --git a/c64/kernal/membot.s b/c64/kernal/membot.s
index 476eefab..509e5858 100644
--- a/c64/kernal/membot.s
+++ b/c64/kernal/membot.s
@@ -1,13 +1,23 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 287/288
+;; - [CM64] Compute's Mapping the Commodore 64 - page 240
+;;
+;; CPU registers that has to be preserved (see [RG64]): .A
+;;
+
 membot:
-	; p287 C64 Programmers reference guide
-	;;  http://unusedino.de/ec64/technical/project64/mapping_c64.html
+
 	bcc membot_set
 	
-	LDX MEMSTR+0
-	LDY MEMSTR+1
+	ldx MEMSTR+0
+	ldy MEMSTR+1
 	rts
+
 membot_set:
+
 	stx MEMSTR+0
 	stx MEMSTR+1
 	
diff --git a/c64/kernal/memtop.s b/c64/kernal/memtop.s
index 70c94fc3..2672c632 100644
--- a/c64/kernal/memtop.s
+++ b/c64/kernal/memtop.s
@@ -1,14 +1,23 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 288
+;; - [CM64] Compute's Mapping the Commodore 64 - page 240
+;;
+;; CPU registers that has to be preserved (see [RG64]): .A
+;;
+
 memtop:
-	; p288 C64 Programmer's reference guide
-	; but for now we only support reading it
-	;;  http://unusedino.de/ec64/technical/project64/mapping_c64.html
+
 	bcc memtop_set
 	
-	LDY MEMSIZ+1
-	LDX MEMSIZ+0
+	ldy MEMSIZ+1
+	ldx MEMSIZ+0
 	rts
+
 memtop_set:
+
 	sty MEMSIZ+1
 	stx MEMSIZ+0
 	
diff --git a/c64/kernal/open.s b/c64/kernal/open.s
index 189e4227..8d494dfe 100644
--- a/c64/kernal/open.s
+++ b/c64/kernal/open.s
@@ -1,29 +1,88 @@
-	; Function defined on pp272-273 of C64 Programmers Reference Guide
-	;; See also http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
 
-	;; Sequence is:
-	;; 1. Call current device to attention as LISTENER = $20 + device
-	;; 2. 
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 289
+;; - [CM64] Compute's Mapping the Commodore 64 - page 230/231
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
+
 open:
 
-	;; Disable IRQs, since timing matters!
-	SEI
+	;; Reset status
+	jsr kernalstatus_reset
 
-	;; Begin sending under attention
-	jsr iec_assert_atn
+	;; Check if the logical file number is unique
+	ldy LDTND
+*
+	beq +
+	dey
+	lda LAT, y
+	cmp current_logical_filenum
+	beq kernalerror_FILE_ALREADY_OPEN
+	cpy #$00
+	jmp -
+*
+	;; Check if we have space in tables
 
-	;; CLK is now asserted, and we are ready to transmit a byte
-	lda #$28
-	jsr iec_tx_byte
-	bcs open_error
+	ldy LDTND
+	cpy #$0A
+	bcc open_has_space
+*
+	;; Table is full
+	jmp kernalerror_TOO_MANY_OPEN_FILES
 
-	;; Indicate success
-	lda #$00
-	clc	
+open_has_space:
 
-open_error:
-	;; Re-enable interrupts and return
-	;; (iec_tx_byte will have set/cleared C flag and put result code
-	;; in A if it was an error).
-	cli
+	;; Update the tables
+
+	;; LAT / FAT / SAT support implemented according to
+	;; 'Compute's Mapping the Commodore 64', page 52
+
+	lda current_logical_filenum
+	sta LAT, y
+	lda current_device_number
+	sta FAT, y
+	lda current_secondary_address
+	sta SAT, y
+
+	iny
+	sty LDTND
+
+	;; Check for command to send
+	lda FNLEN
+	beq open_done_success
+	
+	;; Check for IEC device
+	lda current_device_number
+	jsr iec_check_devnum
+	bcc open_iec
+
+	;; FALLTROUGH
+open_done_success:
+
+	clc
 	rts
+
+open_iec:
+
+	;; We have a command to send to IEC device
+	jsr listen
+	bcc +
+	jmp kernalerror_DEVICE_NOT_FOUND
+*
+	lda current_secondary_address
+	jsr iec_cmd_open
+	bcc +
+	jmp kernalerror_DEVICE_NOT_FOUND ; XXX find a better error message for wrong channel (create new one?)
+*
+
+	;; We need our helpers to get to filenames under ROMs or IO area
+	jsr install_ram_routines
+
+	;; Send command ('file name')
+	jsr lvs_send_file_name
+
+	jmp open_done_success
diff --git a/c64/kernal/plot.s b/c64/kernal/plot.s
index 95a3cb6d..439b1828 100644
--- a/c64/kernal/plot.s
+++ b/c64/kernal/plot.s
@@ -1,2 +1,12 @@
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 290
+;; - [CM64] Compute's Mapping the Commodore 64 - page 215
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
 plot:
 	rts
diff --git a/c64/kernal/printf.s b/c64/kernal/printf.s
index f18217ba..245e9636 100644
--- a/c64/kernal/printf.s
+++ b/c64/kernal/printf.s
@@ -112,7 +112,7 @@ not_hexword:
 
 not_pointer:	
 	;; Print character
-	jsr $ffd2
+	jsr JCHROUT
 
 printf_nextchar:
 	jsr printf_advance
@@ -148,11 +148,11 @@ printf_printhexbyte:
 	cmp #$3A
 	bcc +
 	adc #6
-*	jsr $ffd2
+*	jsr JCHROUT
 	pla
 	and #$0f
 	ora #$30
 	cmp #$3A
 	bcc +
 	adc #6
-*	jmp $ffd2
+*	jmp JCHROUT
diff --git a/c64/kernal/ramtas.s b/c64/kernal/ramtas.s
index 45de1315..81f4dfde 100644
--- a/c64/kernal/ramtas.s
+++ b/c64/kernal/ramtas.s
@@ -1,14 +1,23 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 291
+;; - [CM64] Compute's Mapping the Commodore 64 - page 237
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
 ramtas:
 	; C64 Programmer's Reference guide p291:
 	; Clear $0000-$0101, $0200-$03ff
 	; PGS: $0000, $0001 are CPU IO ports, so shouldn't get written to
-	LDY #$02
-	LDA #$00
+	ldy #$02
+	lda #$00
 ramtas_l1:
-	STA $00,Y
-	INY
-	BNE ramtas_l1
+	sta $00,Y
+	iny
+	bne ramtas_l1
 ramtas_l2:
 	;; How many ways are there to efficiently erase these two pages
 	;; of RAM? We would like to avoid any unnecessary byte similarity
@@ -16,41 +25,41 @@ ramtas_l2:
 	;; with the longer sequence of identicale bytes we see no basis for
 	;; it being copyrightable.  Again, we just want to redue the attack
 	;; surface for any misguided suit.
-	STA $0300,Y
-	STA $0200,Y
-	INY
-	BNE ramtas_l2
+	sta $0300,Y
+	sta $0200,Y
+	iny
+	bne ramtas_l2
 
 	; allocate cassette buffer
 	;; "Mapping the C128", p61
 	lda #<$033C
-	STA cassette_buffer_ptr+0
+	sta cassette_buffer_ptr+0
 	lda #>$033C
-	STA cassette_buffer_ptr+1
+	sta cassette_buffer_ptr+1
 
 	; set screen address to $0400
 	; https://www.c64-wiki.com/wiki/Screen_RAM
 	; Since we are setting $D018, we also make sure we are using the 
 	; ROM character set (C64 Programmer's Reference Guide p322)
-	LDA #$14
-	STA $D018
+	lda #$14
+	sta VIC_YMCSB
 
 	; Make sure we have the correct VIC-II memory bank for the screen to really be at $0400
 	; and not $4400, $8400 or $C400
 	; https://www.c64-wiki.com/wiki/VIC_bank#Selecting_VIC_banks
-	LDA $DD02
-	ORA #$03
-	STA $DD02
-	LDA $DD00
-	ORA #$03
-	STA $DD00
+	lda CIA2_DDRA
+	ora #$03
+	sta CIA2_DDRA
+	lda CIA2_PRA
+	ora #$03
+	sta CIA2_PRA
 
 	;; Set screen address pointer ("Compute's Mapping the 64" p238)
 	;; This is obvious boiler plate containing no creative input, but to avoid
 	;; unnecessarily similarity to the C64 KERNAL, we use X instead of A to do this,
 	;; and several following
-	LDX #>$0400
-	STX HIBASE
+	ldx #>$0400
+	stx HIBASE
 	
 	;;  Work out RAM size and put in MEMSTR and MEMSIZ
 	;; "Compute's Mapping the 64", p54
diff --git a/c64/kernal/rdtim.s b/c64/kernal/rdtim.s
index 89e78575..a9e40a16 100644
--- a/c64/kernal/rdtim.s
+++ b/c64/kernal/rdtim.s
@@ -1,3 +1,12 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 291
+;; - [CM64] Compute's Mapping the Commodore 64 - page 232
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
 rdtim:
 	rts
diff --git a/c64/kernal/readst.s b/c64/kernal/readst.s
index 28139f1b..b3fbaa53 100644
--- a/c64/kernal/readst.s
+++ b/c64/kernal/readst.s
@@ -1,3 +1,30 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 292
+;; - [CM64] Compute's Mapping the Commodore 64 - page 239
+;;
+;; CPU registers that has to be preserved (see [RG64]): .X, .Y
+;;
+
 readst:
+
+	;; Check the current device number
+
+	lda current_device_number
+	cmp #$02
+	bne +
+	
+	;; This is RS-232 device - according to 'Compute's Mapping the Commodore 64' page 239
+	;; it reads status from RSSTAT
+	lda RSSTAT
+	rts
+*
+	;; According to 'Compute's Mapping the Commodore 64' page 239, it usually retrieves
+	;; status from IOSTATUS
+	
+	;; XXX is it always the case if device is not RS-232 ?
+
+	lda IOSTATUS
 	rts
diff --git a/c64/kernal/restor.s b/c64/kernal/restor.s
deleted file mode 100644
index 0844288b..00000000
--- a/c64/kernal/restor.s
+++ /dev/null
@@ -1,3 +0,0 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
-restor:
-	rts
diff --git a/c64/kernal/save.s b/c64/kernal/save.s
index e8730e78..e98d030f 100644
--- a/c64/kernal/save.s
+++ b/c64/kernal/save.s
@@ -1,3 +1,13 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 293/294
+;; - [CM64] Compute's Mapping the Commodore 64 - page 231/232
+;; - IEC reference at http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
 save:
 	rts
diff --git a/c64/kernal/scan_keyboard.s b/c64/kernal/scan_keyboard.s
index 61851c3f..8b9de00f 100644
--- a/c64/kernal/scan_keyboard.s
+++ b/c64/kernal/scan_keyboard.s
@@ -1,9 +1,19 @@
-	;; Scan the keyboard..
-	;; Here we don't use the horrible buggy original routine,
-	;; not just because of copyright. Instead, we use the
-	;; nice one with joystick interference removal and
-	;; key roll-over support from
-	;; http://codebase64.org/doku.php?id=base:scanning_the_keyboard_the_correct_and_non_kernal_way
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 295
+;; - [CM64] Compute's Mapping the Commodore 64 - page 220
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
+;; Scan the keyboard..
+;; Here we don't use the horrible buggy original routine,
+;; not just because of copyright. Instead, we use the
+;; nice one with joystick interference removal and
+;; key roll-over support from
+;; http://codebase64.org/doku.php?id=base:scanning_the_keyboard_the_correct_and_non_kernal_way
 
 ;; /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 ;;     Keyboard IO Routine
@@ -324,7 +334,7 @@ next_row:
 	;; so that RUN/STOP etc can be checked easily
 	;; (Compute's Mapping the 64, p27)
 	lda ScanResult+0
-	sta BUCKYSTATUS
+	sta STKEY
 
 	;; Store de-bounce data for bucky keys
 	;; (Compute's Mapping the 64, p58-59)
diff --git a/c64/kernal/screen.s b/c64/kernal/screen.s
new file mode 100644
index 00000000..b2e793fc
--- /dev/null
+++ b/c64/kernal/screen.s
@@ -0,0 +1,19 @@
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 295
+;; - [CM64] Compute's Mapping the Commodore 64 - page 215
+;;
+;; CPU registers that has to be preserved (see [RG64]): .A
+;;
+
+screen:
+
+	;; There are only 2 sane ways to implement this routine,
+	;; I hope this one is different than what Commodore picked :)
+
+	ldy #25 ; 25 columns
+	ldx #40 ; 40 rows
+
+	rts
diff --git a/c64/kernal/second.s b/c64/kernal/second.s
index 65eb7f88..d130cfc5 100644
--- a/c64/kernal/second.s
+++ b/c64/kernal/second.s
@@ -1,3 +1,25 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 296
+;; - [CM64] Compute's Mapping the Commodore 64 - page 223/224
+;; - https://www.pagetable.com/?p=1031, , https://github.com/mist64/cbmbus_doc
+;;
+;; CPU registers that has to be preserved (see [RG64]): .X, .Y
+;;
+
+
 second:
-	rts
+
+	;; Due to OPEN/CLOSE/TKSA/SECOND command encoding (see https://www.pagetable.com/?p=1031),
+	;; allowed channels are 0-15; report error if out of range
+	cmp #$10
+	bcc + 
+	jmp kernalerror_DEVICE_NOT_FOUND ; XXX find a better error message for wrong channel (create new one?)
+*
+	ora #$60
+
+	jmp common_open_close_unlsn_second
+
+
diff --git a/c64/kernal/setfls.s b/c64/kernal/setfls.s
new file mode 100644
index 00000000..ce6892a8
--- /dev/null
+++ b/c64/kernal/setfls.s
@@ -0,0 +1,20 @@
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 297
+;; - [CM64] Compute's Mapping the Commodore 64 - page 238
+;;
+;; CPU registers that has to be preserved (see [RG64]): .A, .X, .Y
+;;
+
+setfls:
+
+	;; There are 6 sane ways to implement this routine,
+	;; I hope this one won't cause similarity to CBM code
+	
+	sta current_logical_filenum
+	sty current_secondary_address
+	stx current_device_number
+	
+	rts
diff --git a/c64/kernal/setlfs.s b/c64/kernal/setlfs.s
deleted file mode 100644
index 742ef38f..00000000
--- a/c64/kernal/setlfs.s
+++ /dev/null
@@ -1,3 +0,0 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
-setlfs:
-	rts
diff --git a/c64/kernal/setmsg.s b/c64/kernal/setmsg.s
index eb79d7f5..fc20350e 100644
--- a/c64/kernal/setmsg.s
+++ b/c64/kernal/setmsg.s
@@ -1,3 +1,13 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 298
+;; - [CM64] Compute's Mapping the Commodore 64 - page 239
+;;
+;; CPU registers that has to be preserved (see [RG64]): .A, .X, .Y
+;;
+
 setmsg:
+	sta MSGFLG
 	rts
diff --git a/c64/kernal/setnam.s b/c64/kernal/setnam.s
index 8c2d0b86..0cbead31 100644
--- a/c64/kernal/setnam.s
+++ b/c64/kernal/setnam.s
@@ -1,3 +1,20 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 298/299
+;; - [CM64] Compute's Mapping the Commodore 64 - page 238
+;;
+;; CPU registers that has to be preserved (see [RG64]): .A, .X, .Y
+;;
+
 setnam:
+
+	;; There are 6 sane ways to implement this routine,
+	;; I hope this one won't cause similarity to CBM code
+
+	sta FNLEN
+	sty FNADDR + 1
+	stx FNADDR + 0
+
 	rts
diff --git a/c64/kernal/settim.s b/c64/kernal/settim.s
index bfc95254..804538c1 100644
--- a/c64/kernal/settim.s
+++ b/c64/kernal/settim.s
@@ -1,3 +1,12 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 299/300
+;; - [CM64] Compute's Mapping the Commodore 64 - page 232
+;;
+;; CPU registers that has to be preserved (see [RG64]): .A, .X, .Y
+;;
+
 settim:
 	rts
diff --git a/c64/kernal/settmo.s b/c64/kernal/settmo.s
index ffd76b69..273fbf43 100644
--- a/c64/kernal/settmo.s
+++ b/c64/kernal/settmo.s
@@ -1,3 +1,12 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 300
+;; - [CM64] Compute's Mapping the Commodore 64 - page 239
+;;
+;; CPU registers that has to be preserved (see [RG64]): .A, .X, .Y
+;;
+
 settmo:
 	rts
diff --git a/c64/kernal/stop.s b/c64/kernal/stop.s
index 2f8e82e2..980bd9bf 100644
--- a/c64/kernal/stop.s
+++ b/c64/kernal/stop.s
@@ -1,17 +1,26 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 301
+;; - [CM64] Compute's Mapping the Commodore 64 - page 232
+;;
+;; CPU registers that has to be preserved (see [RG64]): .Y
+;;
+
 stop:
-	;; Bit 7 of BUCKYSTATUS contains the state of the STOP key
+	;; Bit 7 of STKEY contains the state of the STOP key
 	;; (Compute's Mapping the 64, p27)
 
 	;; BASIC checks carry flag to indicate STOP or not
-	lda BUCKYSTATUS
+	lda STKEY
 	and #$80
 	beq stop_pressed
 
-	;;  By trial and error, we know that Z + C = BREAK
+	;; By trial and error, we know that Z + C = BREAK
 	;; and that neither should be set otherwise
 	lda #$ff
-	clc	
+	clc
 	rts
 
 stop_pressed:
diff --git a/c64/kernal/talk.s b/c64/kernal/talk.s
index 48a341d6..16440aa8 100644
--- a/c64/kernal/talk.s
+++ b/c64/kernal/talk.s
@@ -1,3 +1,32 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 301/302
+;; - [CM64] Compute's Mapping the Commodore 64 - page 223
+;; - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc
+;; - http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+;;
+;; CPU registers that has to be preserved (see [RG64]): .X, .Y
+;;
+
+
 talk:
-	rts
+
+	;; According to serial-bus.pdf (page 15) this routine flushes the IEC out buffer
+	jsr iec_tx_flush
+
+	;; Check whether device number is correct
+	jsr iec_check_devnum
+	bcc +
+	jmp kernalerror_DEVICE_NOT_FOUND
+*
+	;; Encode and execute the command
+	ora #$40
+
+common_talk_listen: ; common part of TALK and LISTEN
+
+	sta IEC_TMP2
+	jmp iec_tx_command
+
+
diff --git a/c64/kernal/tksa.s b/c64/kernal/tksa.s
index 4b599d45..be048d62 100644
--- a/c64/kernal/tksa.s
+++ b/c64/kernal/tksa.s
@@ -1,3 +1,26 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 302
+;; - [CM64] Compute's Mapping the Commodore 64 - page 224
+;; - https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc
+;;
+;; CPU registers that has to be preserved (see [RG64]): .X, .Y
+;;
+
+
 tksa:
-	rts
+
+	;; Due to OPEN/CLOSE/TKSA/SECOND command encoding (see https://www.pagetable.com/?p=1031),
+	;; allowed channels are 0-15; report error if out of range
+	cmp #$10
+	bcc + 
+	jmp kernalerror_DEVICE_NOT_FOUND ; XXX find a better error message for wrong channel (create new one?)
+*
+	ora #$F0
+
+	jmp common_untlk_tksa
+
+
+
diff --git a/c64/kernal/unlsn.s b/c64/kernal/unlsn.s
index 31a35a40..0298c215 100644
--- a/c64/kernal/unlsn.s
+++ b/c64/kernal/unlsn.s
@@ -1,3 +1,25 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 303
+;; - [CM64] Compute's Mapping the Commodore 64 - page 224
+;; - https://www.pagetable.com/?p=1031, , https://github.com/mist64/cbmbus_doc
+;; - http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+;;
+;; CPU registers that has to be preserved (see [RG64]): .X, .Y
+;;
+
+
 unlsn:
-	rts
+
+	;; According to serial-bus.pdf (page 15) this routine flushes the IEC out buffer
+	jsr iec_tx_flush
+
+	;; Buffer empty, send the command
+	lda #$3F
+
+	jmp common_open_close_unlsn_second
+
+
+
diff --git a/c64/kernal/untlk.s b/c64/kernal/untlk.s
index 30a018a4..e8054e0d 100644
--- a/c64/kernal/untlk.s
+++ b/c64/kernal/untlk.s
@@ -1,3 +1,33 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 304
+;; - [CM64] Compute's Mapping the Commodore 64 - page 224
+;; - https://www.pagetable.com/?p=1031, , https://github.com/mist64/cbmbus_doc
+;; - http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+;;
+;; CPU registers that has to be preserved (see [RG64]): .X, .Y
+;;
+
+
 untlk:
+
+	;; According to serial-bus.pdf (page 15) this routine flushes the IEC out buffer
+	jsr iec_tx_flush
+
+	;; Buffer empty, send the command
+	lda #$5F
+
+common_untlk_tksa: ; common part of UNTLK and TKSA
+
+	sta IEC_TMP2
+	jsr iec_tx_command
+	bcs + ; branch if error
+	;; XXX - for TKSA, is it really the right place to do a turnaround? I've got some doubts
+	;; (it forces us to send the TKSA command 'manually' sometimes), but
+	;; Luigi Di Fraia (https://luigidifraia.wordpress.com/2017/06/27/codebase64-on-the-kernal-behaviour/)
+	;; claims TKSA Kernal routine actually does the turnaround
+	jmp iec_turnaround_to_listen
+*
 	rts
diff --git a/c64/kernal/update_jiffy_clock.s b/c64/kernal/update_jiffy_clock.s
index 4d5a6dbb..7e05883a 100644
--- a/c64/kernal/update_jiffy_clock.s
+++ b/c64/kernal/update_jiffy_clock.s
@@ -1,2 +1,12 @@
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 303
+;; - [CM64] Compute's Mapping the Commodore 64 - page 232
+;;
+;; CPU registers that has to be preserved (see [RG64]): .Y
+;;
+
 update_jiffy_clock:
 	rts
diff --git a/c64/kernal/vector.s b/c64/kernal/vector.s
index 8b296793..5fb49426 100644
--- a/c64/kernal/vector.s
+++ b/c64/kernal/vector.s
@@ -1,3 +1,88 @@
-; Function defined on pp272-273 of C64 Programmers Reference Guide
+
+;;
+;; Official Kernal routine, described in:
+;;
+;; - [RG64] C64 Programmer's Reference Guide   - page 293 (RESTOR), 304 (VECTOR)
+;; - [CM64] Compute's Mapping the Commodore 64 - page 237
+;;
+;; CPU registers that has to be preserved (see [RG64]): none
+;;
+
+restor:
+
+	clc ;; clear carry - for writing to system table
+	ldx #<vector_defaults
+	ldy #>vector_defaults
+
+	;; FALLTHROUGH
+
 vector:
+
+.scope
+
+	;; Temporary storage location
+	.alias _caller_arr_ptr CMP0
+
+	;; According to 'Compute's Mapping the Commodore 64' page 237,
+	;; the CBM implementation does not disable IRQs - yet, the
+	;; 'C64 Programmers Reference Guide' does not contain such
+	;; warning and does not mention any preparations needed, so...
+	;; better safe than sorry, disable the IRQ for the duration
+	;; of vector manipulation
+	php
+	cli
+	
+	;; Prepare the user data pointer
+	stx _caller_arr_ptr + 0
+	sty _caller_arr_ptr + 1
+	
+	;; Select routine variant - store or restore vectors
+	ldy #$1F
+	bcc vector_restore
+	
+	;; FALLTHROUGH
+	
+vector_store:
+*
+	lda CINV, y
+	sta (_caller_arr_ptr), y
+	dey
+	bpl -
+	
+	;; Restore status register (IRQ) before return
+	plp
 	rts
+	
+vector_restore:
+*
+	lda (_caller_arr_ptr), y
+	sta CINV, y
+	dey
+	bpl -
+
+	;; Restore status register (IRQ) before return
+	plp
+	rts
+
+.scend
+
+	;; XXX below we have quite a lot of data... should we decouple them?
+
+vector_defaults:
+	.word default_irq_handler    ;; CINV
+	.word $0000                  ;; CBINV    XXX implement this
+	.word $0000                  ;; NMINV    XXX implement this
+	
+	.word open     ;; IOPEN
+	.word close    ;; ICLOSE
+	.word chkin    ;; ICHKIN
+	.word ckout    ;; ICKOUT
+	.word clrchn   ;; ICLRCH
+	.word chrin    ;; IBASIN
+	.word chrout   ;; IBSOUT
+	.word stop     ;; ISTOP
+	.word getin    ;; IGETIN
+	.word clall    ;; ICLALL
+	.word $0000    ;; USRCMD   XXX implement this
+	.word load     ;; ILOAD
+	.word save     ;; ISAVE
diff --git a/c64/kernal/wait1ms.s b/c64/kernal/wait1ms.s
deleted file mode 100644
index c2a24d44..00000000
--- a/c64/kernal/wait1ms.s
+++ /dev/null
@@ -1,14 +0,0 @@
-	;; 16 rasters = 16 x 63 cycles = ~1ms
-	;; (Probably 2 will be bad lines, so we will over-estimate the delay a bit)
-	
-wait1ms:
-	ldx #16
-	lda $d012
-*
-	cmp $d012
-	beq -
-	lda $d012
-	dex
-	bne -
-	rts
-	
diff --git a/strings/000000A9 b/strings/000000A9
new file mode 100644
index 00000000..88f49cb5
--- /dev/null
+++ b/strings/000000A9
@@ -0,0 +1 @@
+A string of empty bytes followed by half an instruction. Not copyrightable
diff --git a/strings/00003C b/strings/00003C
new file mode 100644
index 00000000..0ae5a8af
--- /dev/null
+++ b/strings/00003C
@@ -0,0 +1,3 @@
+$3C byte after some leading $00s
+
+Not creative. Not copyrightable.
diff --git a/strings/0000A9 b/strings/0000A9
new file mode 100644
index 00000000..88f49cb5
--- /dev/null
+++ b/strings/0000A9
@@ -0,0 +1 @@
+A string of empty bytes followed by half an instruction. Not copyrightable
diff --git a/strings/0002A2 b/strings/0002A2
new file mode 100644
index 00000000..ef2431f1
--- /dev/null
+++ b/strings/0002A2
@@ -0,0 +1,3 @@
+address $0200 + LDX# (argument does not match)
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/002090FF b/strings/002090FF
new file mode 100644
index 00000000..4cb0adc7
--- /dev/null
+++ b/strings/002090FF
@@ -0,0 +1,3 @@
+$00 + JSR $FF90 (SETMSG)
+
+Instruction (jump to an official, docummented location) and some part. Not copyrightable.
diff --git a/strings/006020 b/strings/006020
new file mode 100644
index 00000000..f5f52edc
--- /dev/null
+++ b/strings/006020
@@ -0,0 +1,3 @@
+$00 + RTS (or instruction part) + JSR xxxx
+
+Single byte instruction with two halfs, or half of the instruction + half of other. Not copyrightable.
diff --git a/strings/00990001 b/strings/00990001
new file mode 100644
index 00000000..08241cc8
--- /dev/null
+++ b/strings/00990001
@@ -0,0 +1,3 @@
+$00 + STA $0100, Y
+
+Single instruction and some part. Not copyrightable.
diff --git a/strings/00990002 b/strings/00990002
new file mode 100644
index 00000000..8f8f4711
--- /dev/null
+++ b/strings/00990002
@@ -0,0 +1,3 @@
+$00 + STA $0200, Y
+
+Single instruction and some part. Not copyrightable.
diff --git a/strings/00DD60AD00DD09 b/strings/00DD60AD00DD09
new file mode 100644
index 00000000..64861d09
--- /dev/null
+++ b/strings/00DD60AD00DD09
@@ -0,0 +1,5 @@
+address $DD00 (from previous instruction) + RTS (end of the routine, new one starting) + LDA $DD00 + ORA # (argument does not match)
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/0220DA b/strings/0220DA
new file mode 100644
index 00000000..ab518d6c
--- /dev/null
+++ b/strings/0220DA
@@ -0,0 +1,3 @@
+fragment + JSR + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/026020 b/strings/026020
new file mode 100644
index 00000000..e0fe475c
--- /dev/null
+++ b/strings/026020
@@ -0,0 +1,3 @@
+byte $02 + RTS + JSR (address does not match) 
+
+One instruction + some fragments. Not copyrightable.
diff --git a/strings/02B96302 b/strings/02B96302
new file mode 100644
index 00000000..cb17a83e
--- /dev/null
+++ b/strings/02B96302
@@ -0,0 +1,4 @@
+$02 + LDA $0263, X (FAT table access)
+
+Single instruction (indexed access to a documented table) + some part. Not copyrightable.
+
diff --git a/strings/02B96D02 b/strings/02B96D02
new file mode 100644
index 00000000..8ceebc31
--- /dev/null
+++ b/strings/02B96D02
@@ -0,0 +1,3 @@
+$02 + LDA $026D, X (SAT table access)
+
+Single instruction (indexed access to a documented table) + some part. Not copyrightable.
diff --git a/strings/032060 b/strings/032060
new file mode 100644
index 00000000..ab518d6c
--- /dev/null
+++ b/strings/032060
@@ -0,0 +1,3 @@
+fragment + JSR + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/034C09 b/strings/034C09
new file mode 100644
index 00000000..132c73fd
--- /dev/null
+++ b/strings/034C09
@@ -0,0 +1,3 @@
+fragment + JMP + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/034C33 b/strings/034C33
new file mode 100644
index 00000000..132c73fd
--- /dev/null
+++ b/strings/034C33
@@ -0,0 +1,3 @@
+fragment + JMP + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/034C37 b/strings/034C37
new file mode 100644
index 00000000..132c73fd
--- /dev/null
+++ b/strings/034C37
@@ -0,0 +1,3 @@
+fragment + JMP + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/034C48 b/strings/034C48
new file mode 100644
index 00000000..132c73fd
--- /dev/null
+++ b/strings/034C48
@@ -0,0 +1,3 @@
+fragment + JMP + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/034C73 b/strings/034C73
new file mode 100644
index 00000000..132c73fd
--- /dev/null
+++ b/strings/034C73
@@ -0,0 +1,3 @@
+fragment + JMP + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/034C83 b/strings/034C83
new file mode 100644
index 00000000..132c73fd
--- /dev/null
+++ b/strings/034C83
@@ -0,0 +1,3 @@
+fragment + JMP + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/034C9E b/strings/034C9E
new file mode 100644
index 00000000..132c73fd
--- /dev/null
+++ b/strings/034C9E
@@ -0,0 +1,3 @@
+fragment + JMP + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/034CFB b/strings/034CFB
new file mode 100644
index 00000000..132c73fd
--- /dev/null
+++ b/strings/034CFB
@@ -0,0 +1,3 @@
+fragment + JMP + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/034CFC b/strings/034CFC
new file mode 100644
index 00000000..132c73fd
--- /dev/null
+++ b/strings/034CFC
@@ -0,0 +1,3 @@
+fragment + JMP + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/036C1C036C b/strings/036C1C036C
new file mode 100644
index 00000000..ebb399e0
--- /dev/null
+++ b/strings/036C1C036C
@@ -0,0 +1,3 @@
+$03 (most likely adddress higher byte) + JMP ($031C) (via public, documented vector) + JMP (address does not match)
+
+Code similarity due to Kernal API usage convention. Since 6510 CPU does not have indirect JSR, the only sane possibility to use Kernal API vectors in RAM ($0314-$0333) is to have JMP ($address) hardcoded somewhere. The jump table has intentionally strange order (to avoid code similarity as much as possible), but some small similarities can't be avoided in any reasonable way.
diff --git a/strings/036C1E036C b/strings/036C1E036C
new file mode 100644
index 00000000..e6f9e218
--- /dev/null
+++ b/strings/036C1E036C
@@ -0,0 +1,3 @@
+$03 (most likely adddress higher byte) + JMP ($031E) (via public, documented vector) + JMP (address does not match)
+
+Code similarity due to Kernal API usage convention. Since 6510 CPU does not have indirect JSR, the only sane possibility to use Kernal API vectors in RAM ($0314-$0333) is to have JMP ($address) hardcoded somewhere. The jump table has intentionally strange order (to avoid code similarity as much as possible), but some small similarities can't be avoided in any reasonable way.
diff --git a/strings/036C20036C b/strings/036C20036C
new file mode 100644
index 00000000..ab5ed572
--- /dev/null
+++ b/strings/036C20036C
@@ -0,0 +1,3 @@
+$03 (most likely adddress higher byte) + JMP ($0320) (via public, documented vector) + JMP (address does not match)
+
+Code similarity due to Kernal API usage convention. Since 6510 CPU does not have indirect JSR, the only sane possibility to use Kernal API vectors in RAM ($0314-$0333) is to have JMP ($address) hardcoded somewhere. The jump table has intentionally strange order (to avoid code similarity as much as possible), but some small similarities can't be avoided in any reasonable way.
diff --git a/strings/036C22036C b/strings/036C22036C
new file mode 100644
index 00000000..f05b4581
--- /dev/null
+++ b/strings/036C22036C
@@ -0,0 +1,3 @@
+$03 (most likely adddress higher byte) + JMP ($0322) (via public, documented vector) + JMP (address does not match)
+
+Code similarity due to Kernal API usage convention. Since 6510 CPU does not have indirect JSR, the only sane possibility to use Kernal API vectors in RAM ($0314-$0333) is to have JMP ($address) hardcoded somewhere. The jump table has intentionally strange order (to avoid code similarity as much as possible), but some small similarities can't be avoided in any reasonable way.
diff --git a/strings/036C24036C b/strings/036C24036C
new file mode 100644
index 00000000..4b11242c
--- /dev/null
+++ b/strings/036C24036C
@@ -0,0 +1,3 @@
+03 (most likely adddress higher byte) + JMP ($0324) (via public, documented vector) + JMP (address does not match)
+
+Code similarity due to Kernal API usage convention. Since 6510 CPU does not have indirect JSR, the only sane possibility to use Kernal API vectors in RAM ($0314-$0333) is to have JMP ($address) hardcoded somewhere. The jump table has intentionally strange order (to avoid code similarity as much as possible), but some small similarities can't be avoided in any reasonable way.
diff --git a/strings/036C2603 b/strings/036C2603
new file mode 100644
index 00000000..3271b1af
--- /dev/null
+++ b/strings/036C2603
@@ -0,0 +1,3 @@
+$03 (most likely adddress higher byte) + JMP ($0326) (via public, documented vector)
+
+Code similarity due to Kernal API usage convention. Since 6510 CPU does not have indirect JSR, the only sane possibility to use Kernal API vectors in RAM ($0314-$0333) is to have JMP ($address) hardcoded somewhere. The jump table has intentionally strange order (to avoid code similarity as much as possible), but some small similarities can't be avoided in any reasonable way.
diff --git a/strings/036C2A036C b/strings/036C2A036C
new file mode 100644
index 00000000..552a4b08
--- /dev/null
+++ b/strings/036C2A036C
@@ -0,0 +1,4 @@
+$03 (most likely adddress higher byte) + JMP ($032A) (via public, documented vector) + JMP (address does not match)
+
+Code similarity due to Kernal API usage convention. Since 6510 CPU does not have indirect JSR, the only sane possibility to use Kernal API vectors in RAM ($0314-$0333) is to have JMP ($address) hardcoded somewhere. The jump table has intentionally strange order (to avoid code similarity as much as possible), but some small similarities can't be avoided in any reasonable way.
+
diff --git a/strings/036C2C03 b/strings/036C2C03
new file mode 100644
index 00000000..3bf23438
--- /dev/null
+++ b/strings/036C2C03
@@ -0,0 +1,3 @@
+$03 (most likely adddress higher byte) + JMP ($032C) (via public, documented vector)
+
+Code similarity due to Kernal API usage convention. Since 6510 CPU does not have indirect JSR, the only sane possibility to use Kernal API vectors in RAM ($0314-$0333) is to have JMP ($address) hardcoded somewhere. The jump table has intentionally strange order (to avoid code similarity as much as possible), but some small similarities can't be avoided in any reasonable way.
diff --git a/strings/090185 b/strings/090185
new file mode 100644
index 00000000..46ebeb00
--- /dev/null
+++ b/strings/090185
@@ -0,0 +1,3 @@
+ORA #$01 (or part of another instruction) + STA (address does not match)
+
+At most one instruction and a half - not copyrightable.
diff --git a/strings/093020 b/strings/093020
new file mode 100644
index 00000000..e020853f
--- /dev/null
+++ b/strings/093020
@@ -0,0 +1,4 @@
+ORA #$30 + JSR without address
+alternatively a value (part of the instruction) followed by a conditional jump
+
+Instruction and a half. Not copyrightable.
diff --git a/strings/098085 b/strings/098085
new file mode 100644
index 00000000..00d602b9
--- /dev/null
+++ b/strings/098085
@@ -0,0 +1,3 @@
+ORA #$80 (or part of another instruction) + STA (address does not match)
+
+At most one instruction and a half - not copyrightable.
diff --git a/strings/0A90034C b/strings/0A90034C
new file mode 100644
index 00000000..e9598dd7
--- /dev/null
+++ b/strings/0A90034C
@@ -0,0 +1,4 @@
+$0A + BCC addr + JMP (address does not match)
+
+Some part + BCC / JMP combo (typical construction on a 6502, where there is no conditional far jump), even the address does not match. Not copyrightable.
+
diff --git a/strings/0D4C4F4144494E b/strings/0D4C4F4144494E
new file mode 100644
index 00000000..5eae602c
--- /dev/null
+++ b/strings/0D4C4F4144494E
@@ -0,0 +1,5 @@
+<RETURN> / last 'jsr printf' instruction byte (pure coincidence) + "LOADIN" PETSCII string
+
+Not copyrightable.
+
+
diff --git a/strings/0D534541524348494E47 b/strings/0D534541524348494E47
new file mode 100644
index 00000000..240ea5a8
--- /dev/null
+++ b/strings/0D534541524348494E47
@@ -0,0 +1,3 @@
+<RETURN> / last 'jsr printf' instruction byte (pure coincidence) + "SEARCHING" PETSCII string
+
+Not copyrightable.
diff --git a/strings/0D564552494659494E b/strings/0D564552494659494E
new file mode 100644
index 00000000..38121d93
--- /dev/null
+++ b/strings/0D564552494659494E
@@ -0,0 +1,3 @@
+<RETURN> / last 'jsr printf' instruction byte (pure coincidence) + "VERIFYIN" PETSCII string
+
+Not copyrightable.
diff --git a/strings/108D00DD b/strings/108D00DD
new file mode 100644
index 00000000..b0d7830a
--- /dev/null
+++ b/strings/108D00DD
@@ -0,0 +1,3 @@
+part of previous instruction + STA $DD00
+
+Instruction (storing register in a well-known I/O register) preceeded by a half of another one - not copyrightable.
diff --git a/strings/18607820 b/strings/18607820
new file mode 100644
index 00000000..2a01aa66
--- /dev/null
+++ b/strings/18607820
@@ -0,0 +1,3 @@
+CLC + RTS (end of subroutine, another one starts) + SEI + JSR (address does not match)
+
+Nothing creative here. First 2 instruction, which is are a common way to end a subroutine and indicate a success. Afterwards a start of new subroutine, which starts with disabling interrupts. Not copyrightable.
diff --git a/strings/1860A59D10 b/strings/1860A59D10
new file mode 100644
index 00000000..e7a89a08
--- /dev/null
+++ b/strings/1860A59D10
@@ -0,0 +1,3 @@
+CLC + RTS + LDA $9D + BPL
+
+Nothing creative here. First 2 instruction, which is are a common way to end a subroutine and indicate a success. Afterwards a start of new subroutine, which starts by checking a documented zeropage variable. Not copyrightable.
diff --git a/strings/2046524F4D20 b/strings/2046524F4D20
new file mode 100644
index 00000000..d2c609c4
--- /dev/null
+++ b/strings/2046524F4D20
@@ -0,0 +1,3 @@
+<SPACE> + FROM + <SPACE> - PETSCII string
+
+Not copyrightable.
diff --git a/strings/204F5045 b/strings/204F5045
new file mode 100644
index 00000000..bd9f84dd
--- /dev/null
+++ b/strings/204F5045
@@ -0,0 +1,3 @@
+<SPACE> + OPE - PETSCII string
+
+Syllable starting a word is definitely not copyrightable.
diff --git a/strings/208EA6A9 b/strings/208EA6A9
new file mode 100644
index 00000000..809ed04c
--- /dev/null
+++ b/strings/208EA6A9
@@ -0,0 +1,3 @@
+JSR $A68E + LDA # (value does not match)
+
+Instruction and a half. Not copyrightable.
diff --git a/strings/20BDFF20 b/strings/20BDFF20
new file mode 100644
index 00000000..77b74280
--- /dev/null
+++ b/strings/20BDFF20
@@ -0,0 +1,3 @@
+JSR $FFBD (SETNAM) + JSR (address does not match)
+
+Instruction (jump to official, documented location) + one byte of another one. Not copyrightable.
diff --git a/strings/29DF8D00DD b/strings/29DF8D00DD
new file mode 100644
index 00000000..b159a7ac
--- /dev/null
+++ b/strings/29DF8D00DD
@@ -0,0 +1,3 @@
+AND #$DF + STA $DD00
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits. Here we just have a trivial bit manipulation - not creeative, not copyrightable.
diff --git a/strings/29DF8D00DD60AD00DD b/strings/29DF8D00DD60AD00DD
new file mode 100644
index 00000000..8701bf28
--- /dev/null
+++ b/strings/29DF8D00DD60AD00DD
@@ -0,0 +1,5 @@
+AND #$DF + STA $DD00 + RTS + LDA $DD00
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/29EF8D b/strings/29EF8D
new file mode 100644
index 00000000..8e99ad35
--- /dev/null
+++ b/strings/29EF8D
@@ -0,0 +1,3 @@
+AND #$EF + STA without address
+
+Clear a bit + a half of other instruction - not copyrightable.
diff --git a/strings/29EF8D00DD60 b/strings/29EF8D00DD60
new file mode 100644
index 00000000..3a45bb8d
--- /dev/null
+++ b/strings/29EF8D00DD60
@@ -0,0 +1,5 @@
+AND #$EF + STA $DD00 + RTS
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/29EF8D00DD60AD00DD09 b/strings/29EF8D00DD60AD00DD09
new file mode 100644
index 00000000..6fb7f246
--- /dev/null
+++ b/strings/29EF8D00DD60AD00DD09
@@ -0,0 +1,5 @@
+AND #$EF + STA $DD00 + RTS + LDA $DD00 + ORA#
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/29F78D00DD b/strings/29F78D00DD
new file mode 100644
index 00000000..58a79f31
--- /dev/null
+++ b/strings/29F78D00DD
@@ -0,0 +1,3 @@
+AND #$F7 + STA $DD00
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits. Here we just have a trivial bit manipulation - not creeative, not copyrightable.
diff --git a/strings/29F78D00DD60 b/strings/29F78D00DD60
new file mode 100644
index 00000000..bada463b
--- /dev/null
+++ b/strings/29F78D00DD60
@@ -0,0 +1,5 @@
+(beginning of the routine not matching) + AND #$F7 + STA $DD00 + RTS
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/386020 b/strings/386020
new file mode 100644
index 00000000..3693f9aa
--- /dev/null
+++ b/strings/386020
@@ -0,0 +1,3 @@
+SEC + RTS (end of subroutine, new one starts from the next byte) + JSR (address not matching)
+
+One subroutine ends with carry clear, second starts with JSR, but to a different address - accidental similarity, code most likely performs something different in both cases.
diff --git a/strings/3ED0034C37 b/strings/3ED0034C37
new file mode 100644
index 00000000..3850ac4b
--- /dev/null
+++ b/strings/3ED0034C37
@@ -0,0 +1,3 @@
+$3E + BNE addr + JMP $xx37
+
+Some part + BNE / JMP combo (typical construction on a 6502, where there is no conditional far jump), even the address does not fully match. Not copyrightable.
diff --git a/strings/4CBDFFA9 b/strings/4CBDFFA9
new file mode 100644
index 00000000..4caa0103
--- /dev/null
+++ b/strings/4CBDFFA9
@@ -0,0 +1,3 @@
+JMP $FFBD (SETNAM) + LDA #$ (value does not match)
+
+Instruction (jump to an official, documented location) + opcode of another one. Not copyrightable.
diff --git a/strings/4F5045 b/strings/4F5045
new file mode 100644
index 00000000..b7ca79b9
--- /dev/null
+++ b/strings/4F5045
@@ -0,0 +1,3 @@
+ORE - PETSCII string
+
+Not copyrightable.
diff --git a/strings/524F4D b/strings/524F4D
new file mode 100644
index 00000000..b4fe5d3c
--- /dev/null
+++ b/strings/524F4D
@@ -0,0 +1,3 @@
+ROM - PETSCII string
+
+Not copyrightable.
diff --git a/strings/564552 b/strings/564552
new file mode 100644
index 00000000..fd01de08
--- /dev/null
+++ b/strings/564552
@@ -0,0 +1,3 @@
+VER - PETSCII string
+
+Not copyrightable.
diff --git a/strings/5645524946 b/strings/5645524946
new file mode 100644
index 00000000..c9039b3d
--- /dev/null
+++ b/strings/5645524946
@@ -0,0 +1,3 @@
+VERIF - PETSCII string, part of 'VERIFY'
+
+Not copyrightable.
diff --git a/strings/5902D0F8 b/strings/5902D0F8
new file mode 100644
index 00000000..8b870d15
--- /dev/null
+++ b/strings/5902D0F8
@@ -0,0 +1,3 @@
+$0259 (LAT table address) + BNE $F8 (few bytes back)
+
+Instruction + some parts (revealing that this is some manipulation on documented Kernal table). Not copyrightable.
diff --git a/strings/6020A0E5A900 b/strings/6020A0E5A900
new file mode 100644
index 00000000..e69de29b
diff --git a/strings/6031EA b/strings/6031EA
new file mode 100644
index 00000000..e3398d10
--- /dev/null
+++ b/strings/6031EA
@@ -0,0 +1,3 @@
+RTS (ending a subroutine, new one starts) + conditional jump
+
+Nothing creative here - not copyrightable.
diff --git a/strings/60A59D10 b/strings/60A59D10
new file mode 100644
index 00000000..bcc0416b
--- /dev/null
+++ b/strings/60A59D10
@@ -0,0 +1,3 @@
+RTS (belonging to previopus subroutine) + LDA $9D (MSGFLG) + BPL
+
+The only similarity here is, that the subroutine starts by checking a documented variable. Not copyrightable.
diff --git a/strings/60A59D10FB b/strings/60A59D10FB
new file mode 100644
index 00000000..3dc7afb7
--- /dev/null
+++ b/strings/60A59D10FB
@@ -0,0 +1,3 @@
+RTS + LDA $9D (MSGFLG) + BPL $FB
+
+Check documented variable value, utilize nearest RTS (a very common optimization, mentionedd for example here just few days ago: https://gitlab.com/mkslack/Area6510/commit/9bdc624574c76661db302cdbf85559fb0e9e309a) to quit subroutine if the highest bit is not 1 (the easiest way to distinguish 2 documented values of the MSGFLG: $00 and $80). Nothing creative here - not copyrightable.
diff --git a/strings/60AD00DD09 b/strings/60AD00DD09
new file mode 100644
index 00000000..47b2fff5
--- /dev/null
+++ b/strings/60AD00DD09
@@ -0,0 +1,4 @@
+fragment (or, most likely, RTS belonging to previous routine) + LDA $DD00 + ORA without matching argument
+
+$DD00 is a register for VIC bank switching and IEC access, using it typically requires bit manipulation.
+Nothing creative here - not copyrightable.
diff --git a/strings/60AD00DD0910 b/strings/60AD00DD0910
new file mode 100644
index 00000000..465ca2c5
--- /dev/null
+++ b/strings/60AD00DD0910
@@ -0,0 +1,5 @@
+RTS (end of the routine, new one starting) + LDA $DD00 + ORA #$10
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/60AD00DD09108D00DD b/strings/60AD00DD09108D00DD
new file mode 100644
index 00000000..d2e3ec90
--- /dev/null
+++ b/strings/60AD00DD09108D00DD
@@ -0,0 +1,5 @@
+RTS (end of the routine, new one starting) + LDA $DD00 + ORA #$10 + STA $DD00
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/630285 b/strings/630285
new file mode 100644
index 00000000..1eeb6590
--- /dev/null
+++ b/strings/630285
@@ -0,0 +1,3 @@
+address $0263 + STA (address does not match)
+
+Not even a full instruction. Not copyrightable.
diff --git a/strings/686020 b/strings/686020
new file mode 100644
index 00000000..a2a6d383
--- /dev/null
+++ b/strings/686020
@@ -0,0 +1,3 @@
+PLA + RTS (end of subroutine, another one starting) + JSR (address does not match)
+
+End of a routine preserving .A register + part of instruction belonging to another subroutine. Not copyrightable.
diff --git a/strings/6C1A036C b/strings/6C1A036C
new file mode 100644
index 00000000..b2044ce0
--- /dev/null
+++ b/strings/6C1A036C
@@ -0,0 +1,3 @@
+JMP ($031A) (via public, documented vector) + JMP (address does not match)
+
+Code similarity due to Kernal API usage convention. Since 6510 CPU does not have indirect JSR, the only sane possibility to use Kernal API vectors in RAM ($0314-$0333) is to have JMP ($address) hardcoded somewhere. The jump table has intentionally strange order (to avoid code similarity as much as possible), but some small similarities can't be avoided in any reasonable way.
diff --git a/strings/7AA47B b/strings/7AA47B
new file mode 100644
index 00000000..ea849b8b
--- /dev/null
+++ b/strings/7AA47B
@@ -0,0 +1,3 @@
+Access to $7A (but instruction opcode does not match) + LDY $7B ($7A-$7B is a documented vector)
+
+Instruction and a half, clearly a zeropage vector access - not copyrightable.
diff --git a/strings/7AD0034C b/strings/7AD0034C
new file mode 100644
index 00000000..48d269ae
--- /dev/null
+++ b/strings/7AD0034C
@@ -0,0 +1,3 @@
+$7A + BNE with matching address + JMP
+
+Single instruction + some matching parts of two others. Not copyrightable.
diff --git a/strings/9914038810 b/strings/9914038810
new file mode 100644
index 00000000..83b907e4
--- /dev/null
+++ b/strings/9914038810
@@ -0,0 +1,3 @@
+STA $0314, Y + DEY + BPL addr
+
+Part of memory copy routine to set/initialize vector table in RAM (a documented one). There is a limited amount of sane ways to implement this code - ours is clearly different from the original, or there would be more similarities. Such a small fragment of rather common routine is definitely not copyrightable.
diff --git a/strings/A000B17AD0 b/strings/A000B17AD0
new file mode 100644
index 00000000..bece149c
--- /dev/null
+++ b/strings/A000B17AD0
@@ -0,0 +1,3 @@
+LDY #$00 + LDA ($7A), Y + BNE (offset does not match)
+
+Small part of a loop processing data pointed by TEXTPTR - not creative, not copyrightable.
diff --git a/strings/A59AC903 b/strings/A59AC903
new file mode 100644
index 00000000..09302357
--- /dev/null
+++ b/strings/A59AC903
@@ -0,0 +1,3 @@
+LDA $9A (DFLTO) + CMP #$03
+
+Check whether the default output device is screen - not even fully matching the original ROM (different branch instruction used) - might be one onstruction on other architecture. Not copyrightable.
diff --git a/strings/A5BAC902D0 b/strings/A5BAC902D0
new file mode 100644
index 00000000..95880faa
--- /dev/null
+++ b/strings/A5BAC902D0
@@ -0,0 +1,3 @@
+LDA $BA + CMP #$02 + BNE (offset does not match)
+
+Check whether the current device number is 2 (RS-232). Not creative - not copyrightablee.
diff --git a/strings/A67AA47B b/strings/A67AA47B
new file mode 100644
index 00000000..4c546a62
--- /dev/null
+++ b/strings/A67AA47B
@@ -0,0 +1,5 @@
+LDX $7A + LDY $7B
+
+Loading TXTPTR value to X/Y registers, would be 1 instruction on any 16-bit CPU. Not creative - not copyrightable.
+
+
diff --git a/strings/A90020BDFF b/strings/A90020BDFF
new file mode 100644
index 00000000..3d2e939f
--- /dev/null
+++ b/strings/A90020BDFF
@@ -0,0 +1,4 @@
+LDA #$00 + JSR $FFBD (SETNAM routine)
+
+Code to set the file name as empty ($FFBD is a standard, documented address). Trivial - not copyrightable.
+
diff --git a/strings/A90020BDFF20 b/strings/A90020BDFF20
new file mode 100644
index 00000000..52da1afa
--- /dev/null
+++ b/strings/A90020BDFF20
@@ -0,0 +1,3 @@
+LDA #$00 + JSR $FFBD (SETNAM routine) + JSR (address differs)
+
+Code to set the file name as empty ($FFBD is a standard, documented address), followed by jump to subroutine (but placed elsewere). Trivial - not copyrightable.
diff --git a/strings/A9009900 b/strings/A9009900
new file mode 100644
index 00000000..3801d04d
--- /dev/null
+++ b/strings/A9009900
@@ -0,0 +1,3 @@
+LDA #$00 + STA xx00, Y
+
+Instruction and a half (probably a loop zeroing something - but something different in both cases). Not copyrightable.
diff --git a/strings/AA208E b/strings/AA208E
new file mode 100644
index 00000000..46ef467b
--- /dev/null
+++ b/strings/AA208E
@@ -0,0 +1,3 @@
+TAX (or instruction fragment) + JSR + lower byte of jump address
+
+At most instruction and a half - not copyrightable.
diff --git a/strings/B190034C b/strings/B190034C
new file mode 100644
index 00000000..b4bf4caa
--- /dev/null
+++ b/strings/B190034C
@@ -0,0 +1,3 @@
+LDA ($0390), Y + JMP (address does not match)
+
+Instruction and a half - not copyrightable.
diff --git a/strings/B1B0034C b/strings/B1B0034C
new file mode 100644
index 00000000..4df42d32
--- /dev/null
+++ b/strings/B1B0034C
@@ -0,0 +1,3 @@
+LDA ($03B0), Y + JMP (address does not match)
+
+Instruction and a half - not copyrightable.
diff --git a/strings/BAA90085 b/strings/BAA90085
new file mode 100644
index 00000000..007ab7ac
--- /dev/null
+++ b/strings/BAA90085
@@ -0,0 +1,3 @@
+$BA + LDA #$00 + STA (address does not match)
+
+One full instruction (loading acumulator with 0) and some parts - not copyrightable.
diff --git a/strings/BAFF20 b/strings/BAFF20
new file mode 100644
index 00000000..95fcfa02
--- /dev/null
+++ b/strings/BAFF20
@@ -0,0 +1,3 @@
+address $FFBA (jump table position of SETLFS) + JSR without address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/C8B17AF0 b/strings/C8B17AF0
new file mode 100644
index 00000000..f39a32bf
--- /dev/null
+++ b/strings/C8B17AF0
@@ -0,0 +1,3 @@
+INY + LDA ($7A),Y + BEQ (offset does not match)
+
+Small part of a loop processing data pointed by TEXTPTR - not creative, not copyrightable.
diff --git a/strings/C8C4B7 b/strings/C8C4B7
new file mode 100644
index 00000000..c18389c8
--- /dev/null
+++ b/strings/C8C4B7
@@ -0,0 +1,3 @@
+INY + CPY $B7 (FNLEN documented variable)
+
+Tiny part of the loop processing file name or IEC command. Not creative - not copyrightable.
diff --git a/strings/D0034C37 b/strings/D0034C37
new file mode 100644
index 00000000..6fe14834
--- /dev/null
+++ b/strings/D0034C37
@@ -0,0 +1,3 @@
+BNE $03 + JMP xx37
+
+Instruction and a half - part of a common workaround for conditional jumps not reaching far. Not copyrightable.
diff --git a/strings/DD09108D00DD b/strings/DD09108D00DD
new file mode 100644
index 00000000..f263c197
--- /dev/null
+++ b/strings/DD09108D00DD
@@ -0,0 +1,5 @@
+$DD + ORA #$10 + STA $DD00
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/DD29DF8D00DD60AD00DD b/strings/DD29DF8D00DD60AD00DD
new file mode 100644
index 00000000..9979799f
--- /dev/null
+++ b/strings/DD29DF8D00DD60AD00DD
@@ -0,0 +1,5 @@
+$DD + AND #$DF + STA $DD00 + RTS (end of the routine, new one starting) + LDA $DD00
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/DD29DF8D00DD60AD00DD09208D00DD b/strings/DD29DF8D00DD60AD00DD09208D00DD
new file mode 100644
index 00000000..fc3ddb19
--- /dev/null
+++ b/strings/DD29DF8D00DD60AD00DD09208D00DD
@@ -0,0 +1,5 @@
+$DD + AND #$DF + STA $DD00 + RTS (end of the routine, new one starting) + LDA $DD00 + ORA #$20 + STA $DD00
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/DD29EF8D00DD b/strings/DD29EF8D00DD
new file mode 100644
index 00000000..6fcdcaaa
--- /dev/null
+++ b/strings/DD29EF8D00DD
@@ -0,0 +1,5 @@
+$DD + AND #$EF + STA $DD00
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/DD29EF8D00DD60 b/strings/DD29EF8D00DD60
new file mode 100644
index 00000000..4ad51171
--- /dev/null
+++ b/strings/DD29EF8D00DD60
@@ -0,0 +1,5 @@
+$DD + AND #$EF + STA $DD00 + RTS
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/DD29EF8D00DD60AD00DD09 b/strings/DD29EF8D00DD60AD00DD09
new file mode 100644
index 00000000..903213d1
--- /dev/null
+++ b/strings/DD29EF8D00DD60AD00DD09
@@ -0,0 +1,5 @@
+$DD + AND #$EF + STA $DD00 + RTS + LDA #$DD00 + ORA # (argument does not match)
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/DD29F78D00DD60 b/strings/DD29F78D00DD60
new file mode 100644
index 00000000..20b06c7a
--- /dev/null
+++ b/strings/DD29F78D00DD60
@@ -0,0 +1,5 @@
+$DD + AND #$F7 + STA $DD00 + RTS
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/DD60AD00DD09208D00DD b/strings/DD60AD00DD09208D00DD
new file mode 100644
index 00000000..f885c7da
--- /dev/null
+++ b/strings/DD60AD00DD09208D00DD
@@ -0,0 +1,5 @@
+$DD + RTS (end of the routine, new one starting) + LDA $DD00 + ORA #$20 + STA $DD00
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/DF8D00DD b/strings/DF8D00DD
new file mode 100644
index 00000000..a3426d59
--- /dev/null
+++ b/strings/DF8D00DD
@@ -0,0 +1,3 @@
+$EF + STA $DD00
+
+Instruction (storing acumulator in a documented I/O register) and some part. Not copyrightable.
diff --git a/strings/DF8D00DD60AD00DD b/strings/DF8D00DD60AD00DD
new file mode 100644
index 00000000..63207a43
--- /dev/null
+++ b/strings/DF8D00DD60AD00DD
@@ -0,0 +1,5 @@
+$DF + STA $DD00 + RTS + LDA $DD00
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/E5C91DD0 b/strings/E5C91DD0
new file mode 100644
index 00000000..18aee6b1
--- /dev/null
+++ b/strings/E5C91DD0
@@ -0,0 +1,3 @@
+$E5 + CMP #$1D + BNE (offset does not match)
+
+Instruction + some parts. Not copyrightable.
diff --git a/strings/EF8D00DD60AD00DD09 b/strings/EF8D00DD60AD00DD09
new file mode 100644
index 00000000..d8780b0e
--- /dev/null
+++ b/strings/EF8D00DD60AD00DD09
@@ -0,0 +1,5 @@
+$EF + STA $DD00 + RTS + LDA $DD00 + ORA # (value does not match)
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.
diff --git a/strings/F6A90085 b/strings/F6A90085
new file mode 100644
index 00000000..815dc515
--- /dev/null
+++ b/strings/F6A90085
@@ -0,0 +1,3 @@
+$F6 + LDA #$00 + STA ...
+
+A part + instruction to clear the accumulator + opcode of another instruction. Not copyrightable.
diff --git a/strings/F7206F b/strings/F7206F
new file mode 100644
index 00000000..ab518d6c
--- /dev/null
+++ b/strings/F7206F
@@ -0,0 +1,3 @@
+fragment + JSR + lower byte of jump address
+
+Not even a full instruction - not copyrightable.
diff --git a/strings/F78D00DD60 b/strings/F78D00DD60
new file mode 100644
index 00000000..f7b83ec1
--- /dev/null
+++ b/strings/F78D00DD60
@@ -0,0 +1,5 @@
+$F7 + STA $DD00 + RTS
+
+$DD00 is a hardware register, where one typically set/unset/read individual bits.
+Having a set of trivial helper subroutines to set/clear individual bits (or groups of bits) is an obvious solution (thus not copyrightable), some similarities are unevitable.
+Besides, in this case (since the similarity does not even cover a single subroutine from start to end) it is clear that the similar code actually performs slightly different actions.