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work towards CHKIN, CHKOUT and CLRCHN

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FeralChild64 committed 2019-07-21 18:07:03 +02:00
1 parent c30d4b31c9
commit 273eb3ee6a
7 files changed
+182 -125
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STATUS.md
+4 -4
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@@ -88,11 +88,11 @@ NOTE: Even the 'DONE' routines won't support features described as missing in on
| $FFB7 | READST | DONE | |
| $FFBA | SETFLS | DONE | |
| $FFBD | SETNAM | DONE | |
| $FFC0 | OPEN | NOT DONE | * work in progress |
| $FFC0 | OPEN | DONE | |
| $FFC3 | CLOSE | PARTIAL | * work in progress |
| $FFC6 | CHKIN | NOT DONE | * work in progress |
| $FFC9 | CHKOUT | NOT DONE | * work in progress |
| $FFCC | CLRCHN | NOT DONE | * work in progress |
| $FFC6 | CHKIN | PARTIAL | * work in progress |
| $FFC9 | CHKOUT | PARTIAL | * work in progress |
| $FFCC | CLRCHN | PARTIAL | * work in progress |
| $FFCF | CHRIN | NOT DONE | * work in progress |
| $FFD2 | CHROUT | NOT DONE | * work in progress |
| $FFD5 | LOAD | PARTIAL | no VERIFY support yet |
c64/kernal/chkin.s
-27
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@@ -1,27 +0,0 @@
;;
;; Official Kernal routine, described in:
;;
;; - [RG64] C64 Programmer's Reference Guide - page 275
;; - [CM64] Compute's Mapping the Commodore 64 - page 229
;;
;; CPU registers that has to be preserved (see [RG64]): .Y
;;
chkin:
;; Implemented according to 'C64 Programmers Reference Guide', page 277
;; First retrieve the FAT/LAT/SAT table index (and check if file is open)
; txa
; jsr find_fls
; bcs kernalerror_FILE_NOT_OPEN
;; Now we have table index in Y - check if file is open for reading
;; XXX continue implementation
rts
c64/kernal/chkinout.s
+133
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@@ -0,0 +1,133 @@
;;
;; Official Kernal routines, described in:
;;
;; - [RG64] C64 Programmer's Reference Guide - page 275 (CHKIN) / 276 (CHKOUT)
;; - [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 first
lda FAT,Y
jsr iec_devnum_check
bcs chkin_set_device
jsr talk
bcs chkinout_end ; don't set DFLTN in case of failure
chkin_set_device:
lda FAT,Y
sta DFLTN
clc ; for success
;; FALLTROUGH
;; Common part for booth CHKIN and CHKOUT
chkinout_end:
pla
tay
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:
;; CHKOUT implementation
chkout:
;; 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 first
lda FAT,Y
jsr iec_devnum_check
bcs chkin_set_device
jsr listen
bcs chkinout_end ; don't set DFLTO in case of failure
chkout_set_device:
lda FAT,Y
sta DFLTO
clc ; for success
jmp chkinout_end
c64/kernal/chkout.s
-25
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@@ -1,25 +0,0 @@
;;
;; Official Kernal routine, described in:
;;
;; - [RG64] C64 Programmer's Reference Guide - page 276
;; - [CM64] Compute's Mapping the Commodore 64 - page 229
;;
;; CPU registers that has to be preserved (see [RG64]): .Y
;;
chkout:
;; Implemented according to 'C64 Programmers Reference Guide', page 278
;; First retrieve the FAT/LAT/SAT table index (and check if file is open)
; txa
; jsr find_fls
; bcs kernalerror_FILE_NOT_OPEN
;; Now we have table index in Y - check if file is open for writing
;; XXX continue implementation
rts
c64/kernal/clrchn.s
+23
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@@ -9,4 +9,27 @@
;;
clrchn:
;; Restore input device to default
lda DFLTN
jsr iec_devnum_check
bcs +
;; Previous device was IEC one - send UNTALK first
jsr untlk
*
;; Set input device number to keyboard
lda #$00
sta DFLTN
;; Restore output device to default
lda DFLTO
jsr iec_devnum_check
bcs +
;; Previous device was IEC one - send UNLISTEN first
jsr unlsn
*
;; Set output device number to screen
lda #$03
sta DFLTO
rts
c64/kernal/findfls.s
+3 -2
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@@ -1,5 +1,5 @@
;; Just a helper routine
;; 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
@@ -13,7 +13,7 @@ find_fls:
bmi find_fls_not_found ; no more entries
cmp LAT, y
bne - ; does not match, try the next one
clc
rts
@@ -21,3 +21,4 @@ find_fls_not_found:
sec
rts
c64/kernal/open.s
+19 -67
View File
@@ -8,13 +8,23 @@
;; CPU registers that has to be preserved (see [RG64]): none
;;
;; XXX this is only a test implementation, does not do what the Kernal does!
open:
;; LAT / FAT / SAT support implemented according to
;; 'Compute's Mapping the Commodore 64', page 52
;; Reset status
jsr kernalstatus_reset
;; 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
ldy LDTND
@@ -22,15 +32,16 @@ open:
bcs +
bmi open_has_space
*
;; Table is full - according to https://codebase64.org/doku.php?id=base:kernalreference
;; C flag set means error occured
sec
rts
;; Table is full
jmp kernalerror_TOO_MANY_OPEN_FILES
open_has_space:
;; 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
@@ -40,66 +51,7 @@ open_has_space:
iny
sty LDTND
;; Kernal API is shared between several types of devices - we have
;; to dispatch the call to appropriate subroutine
lda current_device_number
beq open_keyboard
cmp #$01
beq open_tape
cmp #$02
beq open_rs232
cmp #$03
beq open_screen
cmp #$1F
bcs +
bmi open_iec
*
;; Device numbers over 30 are not allowed on IEC bus
;; FALLTHROUGH to error routine
open_keyboard:
open_tape:
open_screen:
;; XXX implement support for these devices
lda #$05 ; device not present
sta IOSTATUS
rts
open_rs232:
;; XXX implement support for RS-232
lda #$FF ; set every single error bit to discourage using RS-232
sta RSSTAT
rts
open_iec:
;; Part implemented according to https://www.pagetable.com/?p=1031, https://github.com/mist64/cbmbus_doc
;; XXX note: this is only a temporary test implementation, real 'open' does not send anything to IEC,
;; see http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
;; Request device to talk
lda current_device_number
jsr talk
bcs open_iec_error
;; Send secondary address
lda current_secondary_address
jsr second
bcs open_iec_error
;; Turnaround
jsr iec_turnaround_to_listen
bcs open_iec_error
;; Indicate success
lda #$00
clc
open_iec_error:
;; Carry flag will be set by low-level routines
rts