diff --git a/.gitignore b/.gitignore
index 5fdfc0df..8066747b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,7 +3,6 @@
 
 temp.s
 temp.map
-packed_messages.s
 
 ophis.bin
 build/*
diff --git a/Makefile b/Makefile
index e69e5731..b7b0637e 100644
--- a/Makefile
+++ b/Makefile
@@ -13,6 +13,10 @@ SRC_KERNAL_GENERIC    = $(SRC_KERNAL_COMMON) $(wildcard c64/kernal/,platform_gen
 SRC_KERNAL_MEGA65     = $(SRC_KERNAL_COMMON) $(wildcard c64/kernal/,platform_mega65/*.s)
 SRC_KERNAL_ULTIMATE64 = $(SRC_KERNAL_COMMON) $(wildcard c64/kernal/,platform_ultimate64/*.s)
 
+# List of tools
+
+TOOLS_LIST = build/collect_data build/compress_text build/preprocess build/similarity
+
 # Rules - maintainance
 
 all: build/chargen build/newkern_generic build/newbasic_generic build/newc65 build/newkern_ultimate64 build/newbasic_ultimate64
@@ -21,10 +25,7 @@ clean:
 	@rm -rf build
 	@rm -f temp.s
 	@rm -f temp.map
-	@rm -f c64/basic/packed_messages.s
-
-.PHONY: prep
-prep: Ophis build/collect_data build/compress_text build/preprocess build/similarity
+	@rm -f ophis.bin
 
 Ophis:
 	git submodule init
@@ -59,15 +60,22 @@ build/chargen: build/pngprepare assets/8x8font.png
 
 # Rules - platform 'generic'
 
-build/basic_generic/OUT.BIN: build/preprocess $(SRC_BASIC_GENERIC) c64/basic/packed_messages.s
+build/basic_generic/OUT.BIN: $(TOOLS_LIST) $(SRC_BASIC_GENERIC) build/basic/packed_messages.s
+	@echo
+	@echo ### Building BASIC for generic systems
+	@echo
 	@mkdir -p build/basic_generic
 	@rm -f build/basic_generic/*
 	@for SRC in $(SRC_BASIC_GENERIC); do \
 	    ln -s ../../$$SRC build/basic_generic/$$(basename $$SRC); \
 	done
+	@ln -s ../../build/basic/packed_messages.s build/basic_generic/packed_messages.s
 	build/preprocess -d build/basic_generic -l a000 -h e4d2
 
-build/kernal_generic/OUT.BIN: build/preprocess $(SRC_KERNAL_GENERIC)
+build/kernal_generic/OUT.BIN: $(TOOLS_LIST) $(SRC_KERNAL_GENERIC)
+	@echo
+	@echo ### Building KERNAL for generic systems
+	@echo
 	@mkdir -p build/kernal_generic
 	@rm -f build/kernal_generic/*
 	@for SRC in $(SRC_KERNAL_GENERIC); do \
@@ -86,15 +94,22 @@ build/newbasic_generic: build/newrom_generic Makefile
 
 # Rules - platform 'Mega 65'
 
-build/basic_mega65/OUT.BIN: build/preprocess $(SRC_BASIC_MEGA65) c64/basic/packed_messages.s
+build/basic_mega65/OUT.BIN: $(TOOLS_LIST) $(SRC_BASIC_MEGA65) build/basic/packed_messages.s
+	@echo
+	@echo ### Building BASIC for Mega65
+	@echo
 	@mkdir -p build/basic_mega65
 	@rm -f build/basic_mega65/*
 	@for SRC in $(SRC_BASIC_MEGA65); do \
 	    ln -s ../../$$SRC build/basic_mega65/$$(basename $$SRC); \
 	done
+	@ln -s ../../build/basic/packed_messages.s build/basic_mega65/packed_messages.s
 	build/preprocess -d build/basic_mega65 -l a000 -h e4d2
 
-build/kernal_mega65/OUT.BIN: build/preprocess $(SRC_KERNAL_MEGA65)
+build/kernal_mega65/OUT.BIN: $(TOOLS_LIST) $(SRC_KERNAL_MEGA65)
+	@echo
+	@echo ### Building KERNAL for Mega65
+	@echo
 	@mkdir -p build/kernal_mega65
 	@rm -f build/kernal_mega65/*
 	@for SRC in $(SRC_KERNAL_MEGA65); do \
@@ -119,15 +134,22 @@ build/newc65: build/newkern_mega65 build/newbasic_mega65 build/chargen Makefile
 
 # Rules - platform 'Ultimate 64'
 
-build/basic_ultimate64/OUT.BIN: build/preprocess $(SRC_BASIC_ULTIMATE64) c64/basic/packed_messages.s
+build/basic_ultimate64/OUT.BIN: $(TOOLS_LIST) $(SRC_BASIC_ULTIMATE64) build/basic/packed_messages.s
+	@echo
+	@echo ### Building BASIC for Ultimate 64
+	@echo
 	@mkdir -p build/basic_ultimate64
 	@rm -f build/basic_ultimate64/*
 	@for SRC in $(SRC_BASIC_ULTIMATE64); do \
 	    ln -s ../../$$SRC build/basic_ultimate64/$$(basename $$SRC); \
 	done
+	@ln -s ../../build/basic/packed_messages.s build/basic_ultimate64/packed_messages.s
 	build/preprocess -d build/basic_ultimate64 -l a000 -h e4d2
 
-build/kernal_ultimate64/OUT.BIN: build/preprocess $(SRC_KERNAL_ULTIMATE64)
+build/kernal_ultimate64/OUT.BIN: $(TOOLS_LIST) $(SRC_KERNAL_ULTIMATE64)
+	@echo
+	@echo ### Building KERNAL for Ultimate 64
+	@echo
 	@mkdir -p build/kernal_ultimate64
 	@rm -f build/kernal_ultimate64/*
 	@for SRC in $(SRC_KERNAL_ULTIMATE64); do \
@@ -146,8 +168,9 @@ build/newbasic_ultimate64: build/newrom_ultimate64 Makefile
 
 # Rules - misc
 
-c64/basic/packed_messages.s: Makefile build/compress_text
-	build/compress_text > c64/basic/packed_messages.s
+build/basic/packed_messages.s: Makefile build/compress_text
+	@mkdir -p build/basic
+	build/compress_text > build/basic/packed_messages.s
 
 # Rules - tests
 
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..a024d66f
--- /dev/null
+++ b/c64/aliases/,aliases_ram_lowmem.s
@@ -0,0 +1,33 @@
+;;
+;; Names of ZP and low memory locations (only the implemented ones)
+;; (https://www.c64-wiki.com/wiki/Zeropage)
+;;
+
+	;; $000-$001 - 6502 CPU registers
+
+	;; 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
+
+	;; Kernal vectors - interrupts
+	.alias CINV      $0314
+	.alias CBINV     $0316 
+	.alias NMINV     $0318
+	
+	;; Kernal vectors - routines
+	.alias IOPEN     $031A
+	.alias ICLOSE    $031C
+	.alias ICHKIN    $031E
+	.alias ICKOUT    $0320
+	.alias ICLRCH    $0322
+	.alias IBASIN    $0324
+	.alias IBASOUT   $0326
+	.alias ISTOP     $0328
+	.alias IGETIN    $032A
+	.alias ICLALL    $032C
+	.alias USRCMD    $032E
+	.alias ILOAD     $0330
+	.alias ISAVE     $0331
diff --git a/c64/aliases/.dummy b/c64/aliases/,aliases_rom_basic.s
similarity index 100%
rename from c64/aliases/.dummy
rename to c64/aliases/,aliases_rom_basic.s
diff --git a/c64/aliases/,aliases_rom_kernal.s b/c64/aliases/,aliases_rom_kernal.s
new file mode 100644
index 00000000..bb2bd4e4
--- /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 JCHKOUT   $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 bbee542e..d3b76eab 100644
--- a/c64/basic/,aliases.s
+++ b/c64/basic/,aliases.s
@@ -143,135 +143,6 @@
 	.alias RSSTAT $0297 ; RS-232 status
 	.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
-
-	;; Kernal vectors - interrupts
-	.alias CINV      $0314
-	.alias CBINV     $0316 
-	.alias NMINV     $0318
-	
-	;; Kernal vectors - routines
-	.alias IOPEN     $031A
-	.alias ICLOSE    $031C
-	.alias ICHKIN    $031E
-	.alias ICKOUT    $0320
-	.alias ICLRCH    $0322
-	.alias IBASIN    $0324
-	.alias IBASOUT   $0326
-	.alias ISTOP     $0328
-	.alias IGETIN    $032A
-	.alias ICLALL    $032C
-	.alias USRCMD    $032E
-	.alias ILOAD     $0330
-	.alias ISAVE     $0331
-
-	;; 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 JCHKOUT   $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
-
-	;; 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
-
 	;; 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
 	;; a counter, so that if an NMI occurs, it doesn't crash the machine, but can be captured.
@@ -283,4 +154,3 @@
 	.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/kernal/,aliases.s b/c64/kernal/,aliases.s
index b76ce732..0c30eca1 100644
--- a/c64/kernal/,aliases.s
+++ b/c64/kernal/,aliases.s
@@ -90,128 +90,6 @@
 	.alias RSSTAT $0297 ; RS-232 status
 	.alias pal_or_ntsc $02A6
 
-	;; Kernal vectors - interrupts
-	.alias CINV      $0314
-	.alias CBINV     $0316 
-	.alias NMINV     $0318
-	
-	;; Kernal vectors - routines
-	.alias IOPEN     $031A
-	.alias ICLOSE    $031C
-	.alias ICHKIN    $031E
-	.alias ICKOUT    $0320
-	.alias ICLRCH    $0322
-	.alias IBASIN    $0324
-	.alias IBASOUT   $0326
-	.alias ISTOP     $0328
-	.alias IGETIN    $032A
-	.alias ICLALL    $032C
-	.alias USRCMD    $032E
-	.alias ILOAD     $0330
-	.alias ISAVE     $0331
-
-	;; 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 JCHKOUT   $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
-
-	;; 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
-	
 	;; Under-ROM routines
 	;; (BASIC also includes them. XXX - We should de-duplicate them in a safe manner)
 	.alias missed_nmi_flag         $2A7
@@ -221,12 +99,3 @@
 	.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
 
-	;; CIA#2 - https://www.c64-wiki.com/wiki/CIA#CIA_2
-
-	.alias CI2PRA $DD00 ; VIC bank switching and IEC port
-
-	.alias BIT_CI2PRA_ATN_OUT $08    ; 1 - low (pulled), 0 - high (released)
-	.alias BIT_CI2PRA_CLK_OUT $10    ; 1 - low (pulled), 0 - high (released)
-	.alias BIT_CI2PRA_DAT_OUT $20    ; 1 - low (pulled), 0 - high (released)
-	.alias BIT_CI2PRA_CLK_IN  $40    ; 0 - low (pulled), 1 - high (released)
-	.alias BIT_CI2PRA_DAT_IN  $80    ; 0 - low (pulled), 1 - high (released)
diff --git a/c64/kernal/iec_pull_atn_clk_release_data.s b/c64/kernal/iec_pull_atn_clk_release_data.s
index 7e11d311..7d00da80 100644
--- a/c64/kernal/iec_pull_atn_clk_release_data.s
+++ b/c64/kernal/iec_pull_atn_clk_release_data.s
@@ -5,11 +5,11 @@ iec_pull_atn_clk_release_data:
 	;; 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 CI2PRA
-	ora #BIT_CI2PRA_ATN_OUT          ; pull
-	sta CI2PRA
-	ora #BIT_CI2PRA_CLK_OUT          ; pull
-	sta CI2PRA
-	and #$FF - BIT_CI2PRA_DAT_OUT    ; release
-	sta CI2PRA
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_ATN_OUT          ; pull
+	sta CIA2_PRA
+	ora #BIT_CIA2_PRA_CLK_OUT          ; pull
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_DAT_OUT    ; release
+	sta CIA2_PRA
 	rts
diff --git a/c64/kernal/iec_pull_clk_release_data.s b/c64/kernal/iec_pull_clk_release_data.s
index 613aa4ef..38be0f89 100644
--- a/c64/kernal/iec_pull_clk_release_data.s
+++ b/c64/kernal/iec_pull_clk_release_data.s
@@ -5,9 +5,9 @@ iec_pull_clk_release_data:
 	;; 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 CI2PRA
-	ora #BIT_CI2PRA_CLK_OUT          ; pull
-	sta CI2PRA
-	and #$FF - BIT_CI2PRA_DAT_OUT    ; release
-	sta CI2PRA
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_CLK_OUT          ; pull
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_DAT_OUT    ; release
+	sta CIA2_PRA
 	rts
diff --git a/c64/kernal/iec_pull_data_release_atn_clk.s b/c64/kernal/iec_pull_data_release_atn_clk.s
index 7b2a18d0..14e0e236 100644
--- a/c64/kernal/iec_pull_data_release_atn_clk.s
+++ b/c64/kernal/iec_pull_data_release_atn_clk.s
@@ -5,11 +5,11 @@ iec_pull_data_release_atn_clk:
 	;; 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 CI2PRA
-	ora #BIT_CI2PRA_DAT_OUT         ; pull
-	sta CI2PRA
-	and #$FF - BIT_CI2PRA_CLK_OUT   ; release
-	sta CI2PRA
-	and #$FF - BIT_CI2PRA_ATN_OUT   ; release
-	sta CI2PRA
+	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_release_atn.s b/c64/kernal/iec_release_atn.s
index 194f3856..2aef8984 100644
--- a/c64/kernal/iec_release_atn.s
+++ b/c64/kernal/iec_release_atn.s
@@ -1,8 +1,8 @@
 
 iec_release_atn:
 
-	lda CI2PRA
-	and #$FF - BIT_CI2PRA_ATN_OUT    ; release
-	sta CI2PRA
+	lda CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_ATN_OUT    ; release
+	sta CIA2_PRA
 	rts
 
diff --git a/c64/kernal/iec_release_atn_clk_data.s b/c64/kernal/iec_release_atn_clk_data.s
index 3fccfbcb..904ee13f 100644
--- a/c64/kernal/iec_release_atn_clk_data.s
+++ b/c64/kernal/iec_release_atn_clk_data.s
@@ -5,12 +5,12 @@ iec_release_atn_clk_data:
 	;; 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 CI2PRA
-	and #$FF - BIT_CI2PRA_ATN_OUT    ; release
-	sta CI2PRA
-	and #$FF - BIT_CI2PRA_DAT_OUT    ; release
-	sta CI2PRA
-	and #$FF - BIT_CI2PRA_CLK_OUT    ; release
-	sta CI2PRA
+	lda CIA2_PRA
+	and #$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_release_clk_data.s b/c64/kernal/iec_release_clk_data.s
index e74ff7e4..f48daa6c 100644
--- a/c64/kernal/iec_release_clk_data.s
+++ b/c64/kernal/iec_release_clk_data.s
@@ -5,9 +5,9 @@ iec_release_clk_data:
 	;; 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 CI2PRA
-	and #$FF - BIT_CI2PRA_DAT_OUT    ; release
-	sta CI2PRA
-	and #$FF - BIT_CI2PRA_CLK_OUT    ; release
-	sta CI2PRA
+	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_release_clk_pull_data.s b/c64/kernal/iec_release_clk_pull_data.s
index 1c167a04..9f252ed3 100644
--- a/c64/kernal/iec_release_clk_pull_data.s
+++ b/c64/kernal/iec_release_clk_pull_data.s
@@ -5,9 +5,9 @@ iec_release_clk_pull_data:
 	;; 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 CI2PRA
-	ora #BIT_CI2PRA_DAT_OUT          ; pull
-	sta CI2PRA
-	and #$FF - BIT_CI2PRA_CLK_OUT    ; release
-	sta CI2PRA
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_DAT_OUT          ; pull
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_CLK_OUT    ; release
+	sta CIA2_PRA
 	rts
diff --git a/c64/kernal/iec_rx_byte.s b/c64/kernal/iec_rx_byte.s
index 4a7eb996..9819636c 100644
--- a/c64/kernal/iec_rx_byte.s
+++ b/c64/kernal/iec_rx_byte.s
@@ -24,8 +24,8 @@ iec_rx_byte:
 
 	ldx #$11                ; 2 cycles
 iec_rx_clk_wait1:
-	lda CI2PRA              ; 4 cycles
-	rol                     ; 2 cycles, to put BIT_CI2PRA_CLK_IN as the last bit
+	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
@@ -77,7 +77,7 @@ iec_rx_bit_loop:
 	;; Move data bit into C flag, and loop until bit 6 clears
 	;; i.e., the clock has been released.
 
-*	lda CI2PRA
+*	lda CIA2_PRA
 	rol
 	bpl -
 
@@ -90,8 +90,8 @@ iec_rx_bit_loop:
 	;; consider this a timeout
 	ldy #$19                ; 2 cycles
 iec_rx_clk_wait2:
-	lda CI2PRA              ; 4 cycles
-	rol                     ; 2 cycles, to put BIT_CI2PRA_CLK_IN as the last bit
+	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
diff --git a/c64/kernal/iec_set_idle.s b/c64/kernal/iec_set_idle.s
index dd936926..1604306d 100644
--- a/c64/kernal/iec_set_idle.s
+++ b/c64/kernal/iec_set_idle.s
@@ -1,7 +1,7 @@
 
 iec_set_idle:
-	lda CI2PRA
-	ora #BIT_CI2PRA_CLK_OUT                               ; pull
-	and #$FF - BIT_CI2PRA_DAT_OUT - BIT_CI2PRA_ATN_OUT    ; release
-	sta CI2PRA
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_CLK_OUT                                 ; pull
+	and #$FF - BIT_CIA2_PRA_DAT_OUT - BIT_CIA2_PRA_ATN_OUT    ; release
+	sta CIA2_PRA
 	rts
diff --git a/c64/kernal/iec_turnaround_to_listen.s b/c64/kernal/iec_turnaround_to_listen.s
index b1d0f576..1033b720 100644
--- a/c64/kernal/iec_turnaround_to_listen.s
+++ b/c64/kernal/iec_turnaround_to_listen.s
@@ -14,8 +14,8 @@ iec_turnaround_to_listen:
 	;; Wait for clock line to be pulled by the drive
 	ldx #$FF ; XXX should we really use that high number?
 *
-	lda CI2PRA
-	rol    ; to put BIT_CI2PRA_CLK_IN as the last (sign) bit 
+	lda CIA2_PRA
+	rol    ; to put BIT_CIA2_PRA_CLK_IN as the last (sign) bit 
 	bpl +
 	dex
 	bne -
diff --git a/c64/kernal/iec_tx_byte.s b/c64/kernal/iec_tx_byte.s
index 946c248d..b827d8c2 100644
--- a/c64/kernal/iec_tx_byte.s
+++ b/c64/kernal/iec_tx_byte.s
@@ -21,8 +21,8 @@ iec_tx_byte:
 	;; All done - give device time to tell if they are busy by pulling DATA
 	;; They should do it within 1ms
 	ldx #$FF
-*	lda CI2PRA
-	;; BPL here is checking that bit 7 of $DD00 clears,
+*	lda CIA2_PRA
+	;; BPL here is checking that bit 7 clears,
 	;; i.e, that the DATA line is pulled by drive
 	bpl +
 	dex
diff --git a/c64/kernal/iec_tx_command.s b/c64/kernal/iec_tx_command.s
index 7cde1dce..0e92e2db 100644
--- a/c64/kernal/iec_tx_command.s
+++ b/c64/kernal/iec_tx_command.s
@@ -14,8 +14,8 @@ iec_tx_command:
 	jsr wait1ms
 
 	;; Did at least one device respond by pulling DATA?
-	lda CI2PRA
-	and #BIT_CI2PRA_DAT_IN ; XXX try to optimize this, move to separate routine
+	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
@@ -42,8 +42,8 @@ iec_tx_command:
 	;; 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 wait1ms
-	lda CI2PRA
-	and #BIT_CI2PRA_DAT_IN ; XXX try to optimize this, move to separate routine
+	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
diff --git a/c64/kernal/iec_wait_for_clk_release.s b/c64/kernal/iec_wait_for_clk_release.s
index 6139dd1d..22edfdfa 100644
--- a/c64/kernal/iec_wait_for_clk_release.s
+++ b/c64/kernal/iec_wait_for_clk_release.s
@@ -1,6 +1,7 @@
 
 iec_wait_for_clk_release:
-	lda CI2PRA
-	and #BIT_CI2PRA_CLK_IN
+
+	lda CIA2_PRA
+	and #BIT_CIA2_PRA_CLK_IN
 	beq iec_wait_for_clk_release
 	rts
diff --git a/c64/kernal/iec_wait_for_data_pull.s b/c64/kernal/iec_wait_for_data_pull.s
index d83b57d4..93bbabe9 100644
--- a/c64/kernal/iec_wait_for_data_pull.s
+++ b/c64/kernal/iec_wait_for_data_pull.s
@@ -1,6 +1,7 @@
 
 iec_wait_for_data_pull:
-	lda CI2PRA
+
+	lda CIA2_PRA
 	;; Check the highest bit, which is DATA IN,
 	;; (highest bit set = negative value)
 	bmi iec_wait_for_data_pull
diff --git a/c64/kernal/iec_wait_for_data_release.s b/c64/kernal/iec_wait_for_data_release.s
index e54df9de..dc89638a 100644
--- a/c64/kernal/iec_wait_for_data_release.s
+++ b/c64/kernal/iec_wait_for_data_release.s
@@ -1,6 +1,7 @@
 
 iec_wait_for_data_release:
-	lda CI2PRA
+
+	lda CIA2_PRA
 	;; Check the highest bit, which is DATA IN,
 	;; (highest bit set = negative value)
 	bpl iec_wait_for_data_release
diff --git a/c64/kernal/ramtas.s b/c64/kernal/ramtas.s
index e54f7bd2..81f4dfde 100644
--- a/c64/kernal/ramtas.s
+++ b/c64/kernal/ramtas.s
@@ -12,12 +12,12 @@ 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
@@ -25,41 +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