/gist:01bda1a9dd58c219002ddd6e18b36c3f
Created Aug 13, 2019
32 byte X
| ov = $90 ; == $40, initial value for the overflow counter | |
| ct = $D5 ; == $4F / 79, number of passes. Decrementing, finished at -1 | |
| sp = $D1 ; == $07C0, pointer to the bottom line (only set after scolling) | |
| * = $0304 - (end - scroll) | |
| scroll: jsr $E8EA | |
| loop: ldy ct | |
| lda #$A0 | |
| sta $D020, y | |
| sta (sp), y | |
| sta $07C0 - $B, x | |
| inc $D6 | |
| adc ov | |
| sta ov | |
| dec ct | |
| bmi * | |
| bcc loop - 1 | |
| jmp scroll | |
| end: |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment