mirror of
https://github.com/cc65/cc65.git
synced 2024-12-25 02:29:52 +00:00
71 lines
1.4 KiB
ArmAsm
71 lines
1.4 KiB
ArmAsm
;
|
|
; 2016-02-28, Groepaz
|
|
; 2017-06-26, Greg King
|
|
;
|
|
; char cpeekc (void);
|
|
;
|
|
|
|
.export _cpeekc
|
|
|
|
.import plot, popa
|
|
|
|
.include "zeropage.inc"
|
|
.include "c128.inc"
|
|
|
|
|
|
_cpeekc:
|
|
lda MODE
|
|
bmi @c80
|
|
|
|
ldy CURS_X
|
|
lda (SCREEN_PTR),y ; get char
|
|
|
|
@return:
|
|
and #<~$80 ; remove reverse flag
|
|
|
|
; Convert the screen code into a PetSCII code.
|
|
; $00 - $1F: +$40
|
|
; $20 - $3F
|
|
; $40 - $5f: +$20
|
|
; $60 - $7F: +$40
|
|
|
|
cmp #$20
|
|
bcs @sk1 ;(bge)
|
|
ora #$40
|
|
rts
|
|
|
|
@sk1: cmp #$40
|
|
bcc @end ;(blt)
|
|
cmp #$60
|
|
bcc @sk2 ;(blt)
|
|
;sec
|
|
adc #$20 - $01
|
|
@sk2: ;clc ; both above cmp and adc clear carry flag
|
|
adc #$20
|
|
@end: rts
|
|
|
|
@c80:
|
|
lda SCREEN_PTR
|
|
ldy SCREEN_PTR+1
|
|
clc
|
|
adc CURS_X
|
|
bcc @s
|
|
iny
|
|
|
|
; get byte from VDC mem
|
|
@s: 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
|
|
jmp @return
|