mirror of
https://github.com/cc65/cc65.git
synced 2024-12-25 02:29:52 +00:00
285aaf8933
function description for functions that don't take any parameters. git-svn-id: svn://svn.cc65.org/cc65/trunk@5573 b7a2c559-68d2-44c3-8de9-860c34a00d81
63 lines
964 B
ArmAsm
63 lines
964 B
ArmAsm
;
|
|
; Ullrich von Bassewitz, 14.09.2001
|
|
;
|
|
|
|
.export _clrscr
|
|
.import plot
|
|
|
|
.include "cbm510.inc"
|
|
.include "extzp.inc"
|
|
|
|
; ------------------------------------------------------------------------
|
|
; void clrscr (void);
|
|
|
|
.proc _clrscr
|
|
|
|
lda #0
|
|
sta CURS_X
|
|
sta CURS_Y
|
|
jsr plot ; Set cursor to top left corner
|
|
|
|
ldx #$00 ; Count
|
|
jsr clearpage
|
|
jsr clearpage
|
|
jsr clearpage
|
|
ldx #<(40*25) ; Count
|
|
jsr clearpage ; Clear remainder of last page
|
|
jmp plot ; Set screen pointer again
|
|
|
|
.endproc
|
|
|
|
|
|
.proc clearpage
|
|
|
|
txa
|
|
pha ; Save count
|
|
|
|
lda #$20 ; Screencode for blank
|
|
ldy #$00
|
|
@L1: sta (SCREEN_PTR),y
|
|
iny
|
|
dex
|
|
bne @L1
|
|
inc SCREEN_PTR+1
|
|
|
|
pla
|
|
tax ; Reload count
|
|
lda IndReg
|
|
pha
|
|
lda #$0F
|
|
sta IndReg ; Switch to the system bank
|
|
lda CHARCOLOR ; Load color
|
|
ldy #$00
|
|
@L2: sta (CRAM_PTR),y
|
|
iny
|
|
dex
|
|
bne @L2
|
|
inc CRAM_PTR+1
|
|
pla
|
|
sta IndReg ; Restore the old indirect bank
|
|
rts
|
|
|
|
.endproc
|