50 lines
674 B
ArmAsm
50 lines
674 B
ArmAsm
GBASL = $26
|
|
GBASH = $27
|
|
HGRPAGE = $E6
|
|
|
|
PAGE0 = $C054
|
|
PAGE1 = $C055
|
|
|
|
HGR = $F3E2
|
|
HGR2 = $F3D8
|
|
HCLR = $F3F2
|
|
HPOSN = $F411
|
|
WAIT = $FCA8 ;; delay 1/2(26+27A+5A^2) us
|
|
|
|
stars:
|
|
jsr HGR
|
|
jsr HGR2
|
|
; lda #0
|
|
; sta ybase
|
|
lda #$20
|
|
sta HGRPAGE
|
|
|
|
move_stars:
|
|
lda HGRPAGE
|
|
cmp #$20
|
|
beq show_page1
|
|
show_page2:
|
|
bit PAGE1
|
|
lsr HGRPAGE
|
|
bne doit
|
|
|
|
show_page1:
|
|
bit PAGE0
|
|
asl HGRPAGE
|
|
|
|
doit:
|
|
jsr HCLR
|
|
|
|
; FORI=1TO10
|
|
; A=X(I)
|
|
; B=Y(I)
|
|
; C=Z(I)*.1
|
|
; X(I)=A+(A-140)*C
|
|
; Y(I)=B+(B-96)*C
|
|
; Z(I)=Z(I)+.1
|
|
; IFX(I)<0ORX(I)>279ORY(I)<0ORY(I)>191THENX(I)=RND(1)*280:Y(I)=RND(1)*192:Z(I)=0:GOTO7
|
|
;HPLOTA,BTOX(I),Y(I)
|
|
;NEXTI
|
|
|
|
jmp move_stars
|