dos33fsprogs/demos/lovebyte2021/tiny_pastel/tiny_pastel.s
2021-03-14 20:49:24 -04:00

31 lines
685 B
ArmAsm

; Tiny Pastel
; draw some scrolling pastel blocks in 16 bytes
; by Vince `deater` Weaver <vince@deater.net>, --- dSr ---
; zero page locations
; ROM calls
SETCOL = $F864 ; COLOR=A
PRHEX = $FDE3 ; print hex digit
COUT = $FDED ; output A to screen
SETGR = $FB40 ; set lo-res graphics and clear screen
.zeropage
tiny_xdraw:
bit $C050 ; switch to lo-res graphics
tiny_loop:
txa
eor $00,X ; get value from zero page
jsr SETCOL ; set bottom nibble to top
jsr COUT ; print to text screen (which is same
; as lo-res graphics screen) with scroll
inx
jmp tiny_loop ; could use bvc to save a byte
; but we can be sure here and we have
; a byte to spare