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cc65/libsrc/atari/cgetc.s

72 lines
1.5 KiB
ArmAsm

;
; Christian Groessler, November-2002
;
; get a char from the keyboard
; char cgetc(void)
;
.include "atari.inc"
.export _cgetc,setcursor
.import KEYBDV_handler
.import cursor,mul40
_cgetc:
jsr setcursor
lda #12
sta ICAX1Z ; fix problems with direct call to KEYBDV
.ifndef __ATARIXL__
jsr @1
.else
jsr KEYBDV_handler
.endif
ldx #0
rts
.ifndef __ATARIXL__
@1: lda KEYBDV+5
pha
lda KEYBDV+4
pha
rts
.endif
.proc setcursor
ldy #0
lda OLDCHR
sta (OLDADR),y
lda ROWCRS
jsr mul40
clc
adc SAVMSC ; add start of screen memory
sta OLDADR
txa
adc SAVMSC+1
sta OLDADR+1
lda COLCRS
adc OLDADR
sta OLDADR
bcc nc
inc OLDADR+1
nc: lda (OLDADR),y
sta OLDCHR
ldx cursor ; current cursor setting as requested by the user
beq off
ldx #0
beq cont
off: inx
cont: stx CRSINH ; update system variable
beq turnon
and #$7f ; clear high bit / inverse flag
finish: sta (OLDADR),y ; update on-screen display
rts
turnon: ora #$80 ; set high bit / inverse flag
bne finish
.endproc