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fix cpeeks() for C128 VDC

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This commit is contained in:
mrdudz 2017-12-12 17:05:24 +01:00
parent 4da22fc6a0
commit 892732f340
1 changed files with 80 additions and 0 deletions
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80
libsrc/c128/cpeeks.s
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@ -1,5 +1,6 @@
; ;
; 2017-07-05, Greg King ; 2017-07-05, Greg King
; 2017-12-12, Groepaz
; ;
; void cpeeks (char* s, unsigned length); ; void cpeeks (char* s, unsigned length);
; ;
@ -22,6 +23,9 @@ _cpeeks:
eor #>$FFFF eor #>$FFFF
sta ptr3+1 sta ptr3+1
lda MODE
bmi c80
lda SCREEN_PTR lda SCREEN_PTR
ldx SCREEN_PTR+1 ldx SCREEN_PTR+1
sta ptr2 sta ptr2
@ -77,3 +81,79 @@ L3: inc ptr3 ; count length
ldy tmp1 ldy tmp1
sta (ptr1),y sta (ptr1),y
rts rts
;-----------------------------------------------------------
c80:
lda SCREEN_PTR
clc
adc CURS_X
sta ptr2
lda SCREEN_PTR+1
adc #0
sta ptr2+1
jsr popax
sta tmp1 ; (will be a .Y index)
stx ptr1+1
ldx #<$0000
stx ptr1
bze L3a ; branch always
L4a:
lda ptr2
ldy ptr2+1
inc ptr2
bne @s
inc ptr2+1
@s:
; get byte from VDC mem
ldx #VDC_DATA_LO
stx VDC_INDEX
@L0: bit VDC_INDEX
bpl @L0
sta VDC_DATA
dex
stx VDC_INDEX
sty VDC_DATA
ldx #VDC_RAM_RW
stx VDC_INDEX
@L1: bit VDC_INDEX
bpl @L1 ; wait for blanking
lda VDC_DATA
and #<~$80 ; remove reverse bit
; Convert the screen code into a PetSCII code.
; $00 - $1F: +$40
; $20 - $3F
; $40 - $5f: +$20
; $60 - $7F: +$40
cmp #$20
blt @sk1 ;(bcc)
cmp #$40
blt L5a
cmp #$60
blt @sk2 ;(bcc)
clc
@sk1: adc #$20
@sk2: ;clc ; both above cmp and adc clear carry flag
adc #$20
L5a: ldy tmp1
sta (ptr1),y
iny
bnz L1a
inc ptr1+1
L1a: sty tmp1
L3a: inc ptr3 ; count length
bnz L4a
inc ptr3+1
bnz L4a
lda #0 ; terminate the string
ldy tmp1
sta (ptr1),y
rts