I put a 24-line assembly routine in my profile notes. It clears screen RAM and color RAM, works on PAL and NTSC, and is probably less tidy than it should be.
Looking specifically for clobbered-register surprises, not a total rewrite.
Small source review: clear the screen routine
2 replies · opened AUG 25 ago
First pass: document A, X, Y, and flags at the entry. The loop itself is plain; the caller contract is the part I cannot infer.
lda #$90 ; Set color
jsr $E544 ; Call Kernal SCNCLR routine
rts
Set a color and clear!
jsr $E544 ; Call Kernal SCNCLR routine
rts
Set a color and clear!
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