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Restructured according to review

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Restructured according to review in pull request #567.

The "inputc" function was moved in slightly modified form
to kbhit.s and replaces the old keyboard scanner.
cgetc() uses the new kbhit() to read a character.
This commit is contained in:
Stephan Mühlstrasser
2019-09-02 20:52:16 +02:00
committed by greg-king5
parent e2007d0743
commit eb2317d014
2 changed files with 198 additions and 236 deletions
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222
libsrc/osic1p/cgetc.s
View File

@@ -2,236 +2,40 @@
; char cgetc (void); ; char cgetc (void);
; ;
.constructor initcgetc
.export _cgetc .export _cgetc
.export inputc
.import cursor .import cursor
.import _kbhit
.include "osic1p.inc" .include "osic1p.inc"
.include "extzp.inc" .include "extzp.inc"
.include "zeropage.inc" .include "zeropage.inc"
; Internal state that needs to be preserved across calls. ; Input routine, show cursor if enabled
; These variables are named after the original memory locations used by the
; 65V PROM MONITOR, until the actual meaning is determined.
.segment "EXTZP" : zeropage
KB0213: .res 1
KB0214: .res 1
KB0215: .res 1
KB0216: .res 1
; Initialize one-character buffer that is filled by kbhit()
.segment "ONCE"
initcgetc:
lda #$00
sta CHARBUF ; No character in buffer initially
sta KB0213 ; Initialize keyboard state
sta KB0214
sta KB0215
sta KB0216
rts
; Input routine from 65V PROM MONITOR, show cursor if enabled
.code .code
_cgetc: _cgetc:
lda CHARBUF ; character in buffer available? ldx CHARBUF ; character in buffer available?
beq nobuffer bne done
tax ; save character in X
lda #$00
sta CHARBUF ; empty buffer
beq restorex ; restore X and return
nobuffer:
lda cursor ; show cursor? lda cursor ; show cursor?
beq nocursor beq nocursor
ldy CURS_X ldy CURS_X
lda (SCREEN_PTR),y ; fetch current character lda (SCREEN_PTR),y ; fetch current character
sta tmp1 ; save it sta tmp1 ; save it
lda #$A1 ; full white square lda #$A1 ; full white square
sta (SCREEN_PTR),y ; store at cursor position sta (SCREEN_PTR),y ; store at cursor position^
nocursor: nocursor:
jsr inputc ; get input character in A jsr _kbhit ; get input character in A
ldx cursor tax ; save A in X, set flags
beq nocursor ; until a key is actually pressed
lda cursor
beq done ; was cursor on? beq done ; was cursor on?
tax ; save A in X
lda tmp1 ; fetch saved character lda tmp1 ; fetch saved character
ldy CURS_X ldy CURS_X
sta (SCREEN_PTR),y ; store at cursor position sta (SCREEN_PTR),y ; store at cursor position
restorex:
txa ; restore saved character from X
done: done:
lda #$00
sta CHARBUF ; empty buffer
txa ; restore saved character from X
ldx #$00 ; high byte of int return value ldx #$00 ; high byte of int return value
rts rts
; Routine to get character from keyboard and return it in A.
; Based on the OSI ROM routine at $FD00 but uses different
; storage locations to avoid corrupting CC65 run-time code.
inputc: txa ; Save X on stack.
pha
tya ; Save Y on stack.
pha
LFD04: lda #$80 ; Bit mask for initial keyboard row
LFD06: jsr LFCBE ; Write keyboard row
jsr LFCC6 ; Read keyboard column
bne LFD13 ; Branch if a key in this column was pressed
lsr a ; Otherwise shift mask to next row
bne LFD06 ; If not done yet, check next row
beq LFD3A ; Branch if last row reached and no key pressed
LFD13: lsr a ; Have a key press. Shift LSB into carry
bcc LFD1F ; Branch if no key pressed in column 0
txa ; Key pressed in row zero. Get the column data
and #$20 ; Mask only the bit for <ESC> as it is the only key in row zero that returns key press
beq LFD3A ; Branch if <ESC> was not the key
lda #$1B ; Set character to <ESC>
bne LFD50 ; Do more processing
LFD1F: jsr LFE86 ; Shift to find bit that is set (in Y)
tya ; Get bit
sta KB0215 ; Save it
asl a ; Multiply by 7 by shifting left three times (X8)...
asl a
asl a
sec ; ...then subtracting one
sbc KB0215
sta KB0215 ; Save value*7 for later lookup in table
txa ; Get the keyboard column
lsr a ; Shift out bit zero (only key there is <SHIFT LOCK>)
asl a ; And shift back
jsr LFE86 ; Shift to find bit that is set (in Y)
beq LFD47 ; Branch if no keys pressed
lda #$00
LFD3A: sta KB0216 ; Save state of <CTRL> and shift keys
LFD3D: sta KB0213
lda #$02 ; Count used for key debouncing
sta KB0214
bne LFD04 ; Go back and scan keyboard again
LFD47: clc
tya ; Get bit number of pressed key
adc KB0215 ; Add previously calculated offset for keyboard row*7
tay
lda LFF3B,y ; Read ASCII code for key from table
LFD50: cmp KB0213 ; Debounce - same as last key scan?
bne LFD3D ; If not, try again
dec KB0214 ; Decrement debounce counter
beq LFD5F ; Branch if done debouncing
jsr LFCDF ; Wait for short delay to debounce keyboard
beq LFD04 ; Go back and scan keyboard.
LFD5F: ldx #$64 ; Was <CONTROL> key down?
cmp KB0216
bne LFD68 ; Branch if not
ldx #$0F
LFD68: stx KB0214
sta KB0216
cmp #$21
bmi LFDD0 ; Done, return key
cmp #$5F
beq LFDD0 ; Done, return key
lda #$01
jsr LFCBE ; Write keyboard row
jsr LFCCF ; Read keyboard column
sta KB0215
and #$01
tax
lda KB0215
and #$06
bne LFDA2
bit KB0213
bvc LFDBB
txa
eor #$01
and #$01
beq LFDBB
lda #$20
bit KB0215
bvc LFDC3
lda #$C0
bne LFDC3
LFDA2: bit KB0213
bvc LFDAA
txa
beq LFDBB
LFDAA: ldy KB0213
cpy #$31
bcc LFDB9
cpy #$3C
bcs LFDB9
lda #$F0
bne LFDBB
LFDB9: lda #$10
LFDBB: bit KB0215
bvc LFDC3
clc
adc #$C0
LFDC3: clc
adc KB0213
and #$7F
bit KB0215
bpl LFDD0
ora #$80
LFDD0: sta KB0215 ; Save pressed key
pla
tay ; Restore saved Y value
pla
tax ; Restore saved Y value
lda KB0215 ; Get pressed key and return in A
rts
; Write keyboard row with value in A.
; Invert the bits before writing.
; Returns original value of A.
LFCBE: eor #$FF
sta KBD
eor #$FF
rts
; Read keyboard column and return in X.
; Sets Z flag if no keys were pressed.
; Saves current value of A.
LFCC6: pha ; Save A
jsr LFCCF ; Read keyboard column
tax ; Save in X
pla ; Restore A
dex ; Decrement and then increment to
inx ; preserve value of X but set flags
rts
; Read keyboard column.
; Invert the bits (pressed key(s) will show up as ones).
LFCCF: lda KBD ; Read keyboard hardware
eor #$FF ; Invert the bits
rts
; Short fixed delay routine.
LFCDF: ldy #$10
LFCE1: ldx #$40
LFCE3: dex
bne LFCE3
dey
bne LFCE1
rts
; Shift A left until we find a 1 in the most significant bit.
; Return the bit number in Y.
LFE86: ldy #$08
LFE88: dey
asl a
bcc LFE88
rts
; Lookup table of keyboard keys for each scan row.
LFF3B: .byte $BD
.byte 'P', ';', '/', ' ', 'Z', 'A', 'Q'
.byte ',', 'M', 'N', 'B', 'V', 'C', 'X'
.byte 'K', 'J', 'H', 'G', 'F', 'D', 'S'
.byte 'I', 'U', 'Y', 'T', 'R', 'E', 'W'
.byte $00, $00, $0D, $0A, 'O', 'L', '.'
.byte $00, '_', '-', ':', '0', '9', '8'
.byte '7', '6', '5', '4', '3', '2', '1'

212
libsrc/osic1p/kbhit.s
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@@ -10,39 +10,197 @@
; in tmp1 and that is set to zero after the first round. ; in tmp1 and that is set to zero after the first round.
; ;
.constructor initkbhit
.export _kbhit .export _kbhit
.import inputc
.include "osic1p.inc" .include "osic1p.inc"
.include "extzp.inc" .include "extzp.inc"
.include "zeropage.inc" .include "zeropage.inc"
_kbhit: ; Internal state that needs to be preserved across calls.
lda #%11011111 ; Mask for only checking the column for the .segment "EXTZP" : zeropage
sta tmp1 ; ESC key in the first keyboard row.
LASTSCAN: .res 1 ; Result of previous keyboard scan
DBNCCNT: .res 1 ; Debounce counter
KBDTMP: .res 1 ; Temporary values
CTRLSHIFT: .res 1 ; State of CTRL and SHIFT keys
; Initialize one-character buffer that is filled by kbhit()
.segment "ONCE"
initkbhit:
lda #$00
sta CHARBUF ; No character in buffer initially
sta LASTSCAN ; Initialize keyboard state
sta DBNCCNT
sta KBDTMP
sta CTRLSHIFT
lda #%11111110 ; Mask for first keyboard row
scan:
sta KBD ; Select keyboard row
tax ; Save A
lda KBD ; Read keyboard columns
ora tmp1 ; Mask out uninteresting keys (only relevant in
; first row)
cmp #$FF ; No keys pressed?
bne keypressed
lda #$00 ; For remaining rows no keys masked
sta tmp1
txa ; Restore A
sec ; Want to shift in ones
rol a ; Rotate row select to next bit position
cmp #$FF ; Done?
bne scan ; If not, continue
lda #$00 ; Return false
tax ; High byte of return is also zero
sta CHARBUF ; No character in buffer
rts rts
keypressed:
jsr inputc ; Get input character in A ; Routine to get character from keyboard and return it in A.
sta CHARBUF ; Save in buffer ; Based on the OSI ROM routine at $FD00 but uses different
; storage locations to avoid corrupting CC65 run-time code.
_kbhit: lda CHARBUF ; Check for previously saved character
beq LFD05
ldx #$00 ; High byte of return is always zero ldx #$00 ; High byte of return is always zero
lda #$01 ; Return true rts ; A contains non-zero character code meaning true
LFD05: lda #$80 ; Bit mask for initial keyboard row
LFD06: jsr LFCBE ; Write keyboard row
jsr LFCC6 ; Read keyboard column
bne LFD13 ; Branch if a key in this column was pressed
lsr a ; Otherwise shift mask to next row
bne LFD06 ; If not done yet, check next row
beq LFD3A ; Branch if last row reached and no key pressed
LFD13: lsr a ; Have a key press. Shift LSB into carry
bcc LFD1F ; Branch if no key pressed in column 0
txa ; Key pressed in row zero. Get the column data
and #$20 ; Mask only the bit for <ESC> as it is the only key in row zero that returns key press
beq LFD3A ; Branch if <ESC> was not the key
lda #$1B ; Set character to <ESC>
bne LFD50 ; Do more processing
LFD1F: jsr LFE86 ; Shift to find bit that is set (in Y)
tya ; Get bit
sta KBDTMP ; Save it
asl a ; Multiply by 7 by shifting left three times (X8)...
asl a
asl a
sec ; ...then subtracting one
sbc KBDTMP
sta KBDTMP ; Save value*7 for later lookup in table
txa ; Get the keyboard column
lsr a ; Shift out bit zero (only key there is <SHIFT LOCK>)
asl a ; And shift back
jsr LFE86 ; Shift to find bit that is set (in Y)
beq LFD47 ; Branch if no keys pressed STM: IS THIS CORRECT?
lda #$00
LFD3A: sta CTRLSHIFT ; Save state of <CTRL> and shift keys
LFD3D: sta LASTSCAN
lda #$02 ; Count used for key debouncing
sta DBNCCNT
ldx #$00 ; High byte of return is always zero
lda #$00 ; Return false
rts rts
LFD47: clc
tya ; Get bit number of pressed key
adc KBDTMP ; Add previously calculated offset for keyboard row*7
tay
lda LFF3B,y ; Read ASCII code for key from table
LFD50: cmp LASTSCAN ; Debounce - same as last key scan?
bne LFD3D ; If not, try again
dec DBNCCNT ; Decrement debounce counter
beq LFD5F ; Branch if done debouncing
jsr LFCDF ; Wait for short delay to debounce keyboard
beq _kbhit ; Go back and scan keyboard.
LFD5F: ldx #$64 ; Was <CONTROL> key down?
cmp CTRLSHIFT
bne LFD68 ; Branch if not
ldx #$0F
LFD68: stx DBNCCNT
sta CTRLSHIFT
cmp #$21
bmi LFDD0 ; Done, return key
cmp #$5F
beq LFDD0 ; Done, return key
lda #$01
jsr LFCBE ; Write keyboard row
jsr LFCCF ; Read keyboard column
sta KBDTMP
and #$01
tax
lda KBDTMP
and #$06
bne LFDA2
bit LASTSCAN
bvc LFDBB
txa
eor #$01
and #$01
beq LFDBB
lda #$20
bit KBDTMP
bvc LFDC3
lda #$C0
bne LFDC3
LFDA2: bit LASTSCAN
bvc LFDAA
txa
beq LFDBB
LFDAA: ldy LASTSCAN
cpy #$31
bcc LFDB9
cpy #$3C
bcs LFDB9
lda #$F0
bne LFDBB
LFDB9: lda #$10
LFDBB: bit KBDTMP
bvc LFDC3
clc
adc #$C0
LFDC3: clc
adc LASTSCAN
and #$7F
bit KBDTMP
bpl LFDD0
ora #$80
LFDD0: sta KBDTMP ; Save pressed key and return in A
sta CHARBUF
rts
; Write keyboard row with value in A.
; Invert the bits before writing.
; Returns original value of A.
LFCBE: eor #$FF
sta KBD
eor #$FF
rts
; Read keyboard column and return in X.
; Sets Z flag if no keys were pressed.
; Saves current value of A.
LFCC6: pha ; Save A
jsr LFCCF ; Read keyboard column
tax ; Save in X
pla ; Restore A
dex ; Decrement and then increment to
inx ; preserve value of X but set flags
rts
; Read keyboard column.
; Invert the bits (pressed key(s) will show up as ones).
LFCCF: lda KBD ; Read keyboard hardware
eor #$FF ; Invert the bits
rts
; Short fixed delay routine.
LFCDF: ldy #$10
LFCE1: ldx #$40
LFCE3: dex
bne LFCE3
dey
bne LFCE1
rts
; Shift A left until we find a 1 in the most significant bit.
; Return the bit number in Y.
LFE86: ldy #$08
LFE88: dey
asl a
bcc LFE88
rts
; Lookup table of keyboard keys for each scan row.
LFF3B: .byte $BD
.byte 'P', ';', '/', ' ', 'Z', 'A', 'Q'
.byte ',', 'M', 'N', 'B', 'V', 'C', 'X'
.byte 'K', 'J', 'H', 'G', 'F', 'D', 'S'
.byte 'I', 'U', 'Y', 'T', 'R', 'E', 'W'
.byte $00, $00, $0D, $0A, 'O', 'L', '.'
.byte $00, '_', '-', ':', '0', '9', '8'
.byte '7', '6', '5', '4', '3', '2', '1'