From 152120a3fe1ee6116bb8dcf761f64d7d2754cf27 Mon Sep 17 00:00:00 2001
From: FeralChild64 <you@example.com>
Date: Wed, 17 Jul 2019 16:56:44 +0200
Subject: [PATCH] more IEC error reporting work

---
 bin/basic                                     | Bin 8192 -> 8192 bytes
 bin/kernal                                    | Bin 8192 -> 8192 bytes
 c64/basic/,aliases.s                          |  63 ++++++++-
 c64/basic/cmd_load.s                          |   5 +-
 .../{set_sane_devnum.s => select_device.s}    |   3 +-
 c64/basic/wedge_dos.s                         |   7 +-
 c64/kernal/,aliases.s                         |  61 +++++++++
 c64/kernal/errors.s                           | 123 +++++++++++-------
 c64/kernal/iec_rx_byte.s                      |  12 +-
 c64/kernal/load.s                             |  78 ++++++-----
 10 files changed, 252 insertions(+), 100 deletions(-)
 rename c64/basic/{set_sane_devnum.s => select_device.s} (87%)

diff --git a/bin/basic b/bin/basic
index ce99e4f6bbd5c6a47185e8e68c13dcab42c02c07..5563b9cd74e92ecafd57e28af98f9bb8953c3bd6 100644
GIT binary patch
delta 648
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zLhXhPAogSvX2tr$8&F~5hB&y$felh%_O2DEYObz!Tz`1OK_CV}YbcGXhDcsL+%h6H
zP+9%vV3rCN76qZzZIjP&=;^Yoe74=^-HMeAtvgpTEMi>1p>Xy81lCojeAcdQ({0gH
z&|0}vyVZ87POBX#{4_b86^vFY?Afr0LE-%W4ZlzFeh_#NFoAWEn9qmxa~YUk_>`=i
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SC}mT4wH6o_o3{zL@B;v*>R93c

delta 687
zcmZp0XmDUzwN7I7MwSOmOnECOKV#BS5?Qs>vekO2RjZA{k_}63S?w+``-rSsz_7?x
zp?1Rt5PPx-vts?;4X7}2LmXUW*9Ivtd)Eq7HCI<VuHU=iAP|F~HIznGLnN;rZW)mp
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zA|NM2;p3`B>|2wjhMyAn31kD&0_H^w5?hl>!>1;_=n(j}G$S>xHDhVU1ty6E1=iJ*
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zx)XWZnSeT9@wPCTuby1Mm(C=ydh$&m1r&7RzYe0L1yn$kqd@8AJpwNLlOG7M0RSBy
BSt$Sj

diff --git a/bin/kernal b/bin/kernal
index d072f2e91771051f6a7b261eb8870f82e374f90a..b992407fc68a9447757675ac94314744bfb3cbbb 100644
GIT binary patch
delta 1327
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delta 1411
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q&oYiiaB3BU41Xe<6*Mxupr}WlVmQpOY-QjNFDG!^80(6(EB^ywzK8Ar

diff --git a/c64/basic/,aliases.s b/c64/basic/,aliases.s
index a9898755..bbee542e 100644
--- a/c64/basic/,aliases.s
+++ b/c64/basic/,aliases.s
@@ -210,7 +210,68 @@
 	.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.
diff --git a/c64/basic/cmd_load.s b/c64/basic/cmd_load.s
index fa5748c6..5eb5b7f0 100644
--- a/c64/basic/cmd_load.s
+++ b/c64/basic/cmd_load.s
@@ -21,8 +21,9 @@ cmd_load:
 	jsr JSETMSG
 	
 	;; XXX handle device number from arguments, if not present, use the call below
-	jsr set_sane_devnum
-	
+	jsr select_device
+	stx current_device_number
+
 	;; Set filename and length
 	lda #$00
 	sta current_filename_length
diff --git a/c64/basic/set_sane_devnum.s b/c64/basic/select_device.s
similarity index 87%
rename from c64/basic/set_sane_devnum.s
rename to c64/basic/select_device.s
index 501bc5d1..48061f8a 100644
--- a/c64/basic/set_sane_devnum.s
+++ b/c64/basic/select_device.s
@@ -1,5 +1,5 @@
 
-set_sane_devnum:
+select_device:
 
 	;; Take last device number, make sure it's a drive
 	;; If not, set to 8 (first drive number)
@@ -12,6 +12,5 @@ set_sane_devnum:
 	bpl +
 	bcs +
 	ldx #$08
-	stx current_device_number
 *
 	rts
diff --git a/c64/basic/wedge_dos.s b/c64/basic/wedge_dos.s
index 167338f7..da0d3788 100644
--- a/c64/basic/wedge_dos.s
+++ b/c64/basic/wedge_dos.s
@@ -6,11 +6,8 @@ wedge_dos:
 	;; Close all the channels, so that wedge has full control
 	jsr wedge_dos_CLALL
 
-	;; Make sure current device number is sane
-	jsr set_sane_devnum
-
-	;; Set remaining file parameters (X already set by set_sane_devnum);
-	;; channel 15 is a typical one for commands
+	;; Set file parameters,  channel 15 is a typical one for commands
+	jsr select_device ; sets X register
 	lda #$0F
 	ldy #$0F
 	jsr JSETFLS
diff --git a/c64/kernal/,aliases.s b/c64/kernal/,aliases.s
index e5616ae3..b76ce732 100644
--- a/c64/kernal/,aliases.s
+++ b/c64/kernal/,aliases.s
@@ -151,6 +151,67 @@
 	.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
diff --git a/c64/kernal/errors.s b/c64/kernal/errors.s
index 33666e62..1f18f5e1 100644
--- a/c64/kernal/errors.s
+++ b/c64/kernal/errors.s
@@ -1,53 +1,88 @@
 
 ;; Kernal error codes are described in 'Commodore 64 Programmer's Reference Guide', page 306
 
-kernalerror_common:
-	sta DFLTN
+kernalerror_ROUTINE_TERMINATED: ; by a STOP key
+	lda #K_ERR_ROUTINE_TERMINATED
 	sec
 	rts
 
-kernalerror_ROUTINE_TERMINATED: ; by a STOP key
-	lda #$00
-	jmp kernalerror_common
-
 kernalerror_TOO_MANY_OPEN_FILES:
-	lda #$01
-	jmp kernalerror_common
-
-kernalerror_FILE_ALREADY_OPEN:
-	lda #$02
-	jmp kernalerror_common
-
-kernalerror_FILE_NOT_OPEN:
-	lda #$03
-	jmp kernalerror_common
-
-kernalerror_FILE_NOT_FOUND:
-	lda #$04
-	jmp kernalerror_common
-
-kernalerror_DEVICE_NOT_FOUND:
-	lda #$05
-	jmp kernalerror_common
-
-kernalerror_FILE_NOT_INPUT:
-	lda #$06
-	jmp kernalerror_common
-
-kernalerror_FILE_NOT_OUTPUT:
-	lda #$07
-	jmp kernalerror_common
-
-kernalerror_FILE_NAME_MISSING:
-	lda #$08
-	jmp kernalerror_common
-	
-kernalerror_ILLEGAL_DEVICE_NUMBER:
-	lda #$09
-	jmp kernalerror_common
-
-kernalerror_TOP_MEM_RS232:
-	lda #$F0
-	sta RSSTAT
+	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/iec_rx_byte.s b/c64/kernal/iec_rx_byte.s
index 943ce880..d91a857d 100644
--- a/c64/kernal/iec_rx_byte.s
+++ b/c64/kernal/iec_rx_byte.s
@@ -28,7 +28,7 @@ iec_rx_clk_wait1:
     
     ;; Timeout - either this is the last byte of stream, or the stream is empty at all.
     ;; Mark end of stream in IOSTATUS
-    jsr iec_rx_set_eoi
+    jsr kernalstatus_EOI
 
 iec_rx_not_empty:
 
@@ -93,7 +93,7 @@ iec_rx_clk_wait2:
     bne iec_rx_clk_wait2    ; 3 cycles if jumped
     
     ;; Timeout
-    jsr iec_rx_set_eoi
+    jsr kernalstatus_EOI
     pla
     sec ; XXX confirm that sec is really a way to report timeout here
     rts
@@ -115,11 +115,3 @@ iec_rx_clk_wait2:
 	clc
 	rts
 
-iec_rx_set_eoi:
-
-	;; Store EOI information in IOSTATUS
-	lda IOSTATUS
-	ora #$40
-	sta IOSTATUS
-
-	rts
diff --git a/c64/kernal/load.s b/c64/kernal/load.s
index bc6b3ac6..d9097d95 100644
--- a/c64/kernal/load.s
+++ b/c64/kernal/load.s
@@ -1,4 +1,4 @@
-				; Function defined on pp272-273 of C64 Programmers Reference Guide
+	; 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
@@ -29,8 +29,7 @@ load:
 	sty load_save_start_ptr+1
 
 	;; Reset status
-	lda #$00
-	sta IOSTATUS
+	jsr kernalstatus_reset
 
 	;; We need our helpers to get to filenames under ROMs or IO area
 	jsr install_ram_routines
@@ -54,16 +53,14 @@ print_filename_loop:
 	iny
 	jmp print_filename_loop
 *
-	;; 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.
+	;; 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 current_device_number
 	jsr listen
-	bcs load_error
+	bcs load_device_not_found_error
 
 	;; Open channel #0 (p16)
 	lda #$00
@@ -105,7 +102,7 @@ sent_filename:
 	;; Command device to unlisten to indicate end of file name. (p16)
 	jsr unlsn
 	bcs load_error
-	jsr iec_set_idle
+	jsr iec_set_idle ;; XXX is it needed?
 
 	;; Now command device to talk (p16)
 	lda current_device_number
@@ -118,20 +115,18 @@ sent_filename:
 
 	;; 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
 
 	;; Get load address and store it if secondary address is zero
-	;; XXX add secondary address check
 	jsr iec_rx_byte
-	bcs file_not_found_error
+	bcs load_file_not_found_error
 	ldx current_secondary_address
 	beq +
 	sta load_save_start_ptr+0
 *
 	jsr iec_rx_byte
-	bcs file_not_found_error
+	bcs load_file_not_found_error
 	ldx current_secondary_address
 	beq +
 	sta load_save_start_ptr+1
@@ -179,11 +174,11 @@ load_loop:
 	bne +
 	inc load_save_start_ptr+1
 	;; If we wrap around to $0000, then this is bad.
-	beq load_error
+	beq load_wrap_around_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:
@@ -221,7 +216,7 @@ load_done:
 	jsr iec_set_idle
 
 	;; Return last address - Compute's Mapping the 64 says without the '+1',
-	;; checked on original ROMs that this is really the case
+	;; checked (short test program) on original ROMs that this is really the case
 	ldx load_save_start_ptr+0
 	ldy load_save_start_ptr+1
 
@@ -229,27 +224,38 @@ load_done:
 	cli
 	rts
 
+load_wrap_around_error:
+
+	;; This error is probably not even detected by C64 Kernal;
+	;; report BASIC error code that looks the most sane
+	cli
+	lda #B_ERR_OVERFLOW
+	sec
+	rts
+	rts
+
+load_device_not_found_error:
+
+	cli
+	jsr kernalstatus_DEVICE_NOT_FOUND
+	jmp kernalerror_DEVICE_NOT_FOUND
+
+load_file_not_found_error:
+
+	cli
+	jmp kernalerror_FILE_NOT_FOUND
+
 load_error:
 
-	;; Advance cursor to next line, if needed
-	lda MSGFLG
-	bpl +
-	lda #$0D
-	jsr JCHROUT
-*
-	;; XXX - Indicate KERNAL (not BASIC) LOAD error condtion
-	sec
-	lda #28
-
-	;; Re-enable interrupts and return
+	;; XXX should we really return BASIC error code here?
 	cli
-	;; (iec_tx_byte will have set/cleared C flag and put result code
-	;; in A if it was an error).
+	lda kernal_load_or_verify_flag
+	beq load_verify_error
+	lda #B_ERR_LOAD
+	bne +
+load_verify_error:
+	lda #B_ERR_VERIFY
+*	
+	sec
 	rts
 
-file_not_found_error:
-	;; Indicate KERNAL error condition for file not found
-	sec
-	lda #$04
-	cli
-	rts