X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=hacks%2Fimages%2Fm6502%2Fstarfield2d.asm;fp=hacks%2Fimages%2Fm6502%2Fstarfield2d.asm;h=4c26efe4a91ceb7c5dfac4ad1146b96b8e95d823;hb=7b34ef992563d7bcbb64cc5597dc45fa24470b05;hp=0000000000000000000000000000000000000000;hpb=c1b9b55ad8d59dc05ef55e316aebf5863e7dfa56;p=xscreensaver diff --git a/hacks/images/m6502/starfield2d.asm b/hacks/images/m6502/starfield2d.asm new file mode 100644 index 00000000..4c26efe4 --- /dev/null +++ b/hacks/images/m6502/starfield2d.asm @@ -0,0 +1,50 @@ +; 2d starfield +; Submitted by Anonymous + +i:ldx #$7 +g:lda $fe + and #3 + adc #1 + sta $0,x + lda $fe + and #$1f + sta $20,x + dex + bpl g +f: + lda #$ff + sta $10 + delay: + nop + dec $10 + bne delay + + lda #$00 + sta $80 + lda #$02 + sta $81 + ldx #$7 +l:lda $20,x + pha + clc + sbc $00,x + and #$1f + sta $20,x + lda $20,x + tay + lda #1 + sta ($80),y + pla + tay + lda #0 + sta ($80),y + lda $80 + clc + adc #$80 + bne n + inc $81 +n:sta $80 + dex + bpl l + jmp f +