pettil
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chitselb
6502 Forth-83 dialect for the Commodore PET 2001
This suggestion shaves four bytes and makes @+ faster, but adds seven ticks to your C@+ ... worth it? ``` #if 0 name=C@+ stack=( addr -- addr+1 c ) tags=nucleus,memory,primitive...
If we're only concerned about the Z flag, we could shave two bytes and a few cycles here, right?: ``` peq lda stackh,x ; [4] eor tos+1 ; [3] bne...
If I understand correctly what's going on, we should be able to save a byte and a couple of cycles here: ``` paday sec ; A+1 = offset to be...
It looks like you're spending five bytes of tricky code to share four bytes of common code. Why not just keep it simple (unless I'm missing something) and give each...
Charlie, are we allowed to trick stackh into holding the full address temporarily to save six bytes? ``` toggle lda stackl,x sta stackh-1,x lda (stackh-1,x) eor tos sta (stackh-1,x) jmp...
Can we improve **enter** a tiny bit by taking advantage of the likelihood that our **IP** won't wrap past $FFFF? ``` enter: ; pull temp from R:, push pip+2 to...
Could we save about five cycles with no size penalty by eliminating the JSR? ``` tuck dex lda #>(next-1) pha lda #
This project looks like fun (when I was a kid the PET2001 machine behind the show window of the downtown business machine shop was totally out of reach, and those...
Does this more straight-forward approach seem more efficient? ``` dodoes: jsr slip stx z tsx lda $0103,x clc adc #1 sta tos lda $0104,x adc #0 sta tos+1 lda pip...
