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cc65/libsrc/pce/clrscr.s

40 lines
836 B
ArmAsm

;
; Clear (erase) the screen.
;
; Support the full 128- x 64-tile background.
;
.export _clrscr
.import plot
.include "pce.inc"
.include "extzp.inc"
_clrscr:
VREG VDC_MAWR, $0000
st0 #VDC_VWR
ldy #$40
rowloop:
ldx #$80
colloop:
st1 #' ' ; low byte of char. index
st2 #$02 ; background color, high nybble of char. index
dex
bne colloop
dey
bne rowloop
; Go to the home position.
stz CURS_X
stz CURS_Y
jmp plot
;-------------------------------------------------------------------------------
; force the init constructor to be imported
.import initconio
conio_init = initconio