mirror of
https://github.com/deater/dos33fsprogs.git
synced 2025-01-03 18:29:53 +00:00
46 lines
731 B
ArmAsm
46 lines
731 B
ArmAsm
; 16B looks like columns
|
|
|
|
; zero page locations
|
|
HGR_SHAPE = $1A
|
|
HGR_SHAPE2 = $1B
|
|
GBASL = $26
|
|
GBASH = $27
|
|
|
|
; ROM calls
|
|
HGR2 = $F3D8
|
|
HGR = $F3E2
|
|
HPOSN = $F411
|
|
XDRAW0 = $F65D
|
|
XDRAW1 = $F661
|
|
|
|
|
|
|
|
tiny_xdraw:
|
|
|
|
; loads at E7 (HGR_SCALE) which is $20 (jsr instruction)
|
|
|
|
jsr HGR2 ; Hi-res, full screen ; 3
|
|
; Y=0, A=0 after this call
|
|
|
|
; we really have to call this, otherwise it won't run
|
|
; on some real hardware
|
|
|
|
|
|
jsr HPOSN ; set screen position to X= (y,x) Y=(a)
|
|
; saves X,Y,A to zero page
|
|
; after Y= orig X/7
|
|
; A and X are ??
|
|
tiny_loop:
|
|
|
|
ldy #$e3
|
|
inx ; X is 1
|
|
|
|
lda #2 ; ROT=2
|
|
jsr XDRAW0 ; XDRAW 1 AT X,Y
|
|
; Both A and X are 0 at exit
|
|
; Z flag set on exit
|
|
; Y varies
|
|
|
|
beq tiny_loop ; bra
|
|
|