more IEC error reporting work

c64/basic/,aliases.s

@@ -211,6 +211,67 @@
 	.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
+
 	;; 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.

c64/basic/cmd_load.s

@@ -21,7 +21,8 @@ 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

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

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
+	;; Set file parameters,  channel 15 is a typical one for commands
-	jsr set_sane_devnum
+	jsr select_device ; sets X register
-
-	;; Set remaining file parameters (X already set by set_sane_devnum);
-	;; channel 15 is a typical one for commands
 	lda #$0F
 	ldy #$0F
 	jsr JSETFLS

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

c64/kernal/errors.s

@@ -1,53 +1,88 @@
 
 ;; Kernal error codes are described in 'Commodore 64 Programmer's Reference Guide', page 306
 
-kernalerror_common:
+kernalerror_ROUTINE_TERMINATED: ; by a STOP key
-	sta DFLTN
+	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
+	lda #K_ERR_TOO_MANY_OPEN_FILES
-	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
 	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

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

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
+	jsr kernalstatus_reset
-	sta IOSTATUS
 
 	;; 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.
+	;; p13, 16; also p16 tells us this routine doesn't mess with the file table
-	;; also p16 tells us this routine doesn't mess with the file table in the C64,
+	;; in the C64, only in the drive.
-	;; 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
+	;; XXX should we really return BASIC error code here?
-	lda MSGFLG
+	cli
-	bpl +
+	lda kernal_load_or_verify_flag
-	lda #$0D
+	beq load_verify_error
-	jsr JCHROUT
+	lda #B_ERR_LOAD
+	bne +
+load_verify_error:
+	lda #B_ERR_VERIFY
 *	
-	;; 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