Asagida denemek, gelistirmek ya da hakkinda yorum yapmak isteyenler icin rutini veriyorum. Butun yorumlariniza acigim. Ozellikle skate ve nightlord'dan siki bir elestiri bekliyorum.
; x = xl
; a = 0.bit => xh
; y = y
plot
sty plmem
sta plmem+1
lda $8b
pha
lda $8c
pha
tya
clc
ror
clc
ror
clc
ror
tay
lda rowscrh,y
sta $8b ;rowbasi high byte
lda rowscrl,y
sta $8c ;rowbasi low byte
lda plmem
and #$07
clc
adc $8c
sta $8c
txa
and #$F8
adc $8c
sta $8c
bcc j2
inc $8b
j2 lda plmem+1
beq j1
inc $8b
j1
lda $8b
sta chg1+2
sta chg1+5
lda $8c
sta chg1+1
sta chg1+4
txa
and #$07
beq xzero
tax
lda #$80
lp1 ror
dex
bne lp1
jmp chg1
xzero lda #$80
chg1 ora $0000
sta $0000
pla
sta $8c
pla
sta $8b
rts
plmem
!byte $00,$00
rowscrh !byte $20,$21,$22,$23,$25,$26,$27,$28,$2a,$2b,$2c,$2d,$2f,$30,$31,$32,$34,$35,$36,$37,$39,$3a,$3b,$3c,$3e,$3f
rowscrl !byte $00,$40,$80,$c0,$00,$40,$80,$c0,$00,$40,$80,$c0,$00,$40,$80,$c0,$00,$40,$80,$c0,$00,$40,$80,$c0,$00,$40