dos33fsprogs/graphics/hgr/shape_table/cats16.s
2023-01-28 19:24:17 -05:00

79 lines
1.3 KiB
ArmAsm

; 16B eventually looks like cats
; smalla artifact at start, can get rid of for 17B
; zero page locations
HGR_SHAPE = $1A
HGR_SHAPE2 = $1B
HGR_BITS = $1C
GBASL = $26
GBASH = $27
A5H = $45
XREG = $46
YREG = $47
; C0-CF should be clear
; D0-DF?? D0-D5 = HGR scratch?
HGR_DX = $D0 ; HGLIN
HGR_DX2 = $D1 ; HGLIN
HGR_DY = $D2 ; HGLIN
HGR_QUADRANT = $D3
HGR_E = $D4
HGR_E2 = $D5
HGR_X = $E0
HGR_X2 = $E1
HGR_Y = $E2
HGR_COLOR = $E4
HGR_HORIZ = $E5
HGR_SCALE = $E7
HGR_SHAPE_TABLE = $E8
HGR_SHAPE_TABLE2= $E9
HGR_COLLISIONS = $EA
HGR_ROTATION = $F9
FRAME = $FC
XPOS = $FD
YPOS = $FF
; ROM calls
HGR2 = $F3D8
HGR = $F3E2
HPOSN = $F411
XDRAW0 = $F65D
XDRAW1 = $F661
HPLOT0 = $F457
cats:
; $E7 is scale, so $20 (from jsr)
jsr HGR2 ; Hi-res, full screen ; 3
; Y=0, A=0 after this call
; A and Y are 0 here.
; X is left behind by the boot process?
; we really have to call this, otherwise it won't run
; on some real hardware
jsr HPLOT0 ; 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:
; use the actual load to avoid artifact at beginning
tay
; ldy #$00 ; uses the text window
ldx #$21
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