Subject: Re: [stella] 6 digit score display and other ramblings|
From: emooney@xxxxxxxxxxxxxxxx (Erik Mooney)
Date: Mon, 16 Mar 1998 04:09:53 GMT
>> The standard routine (don't think there IS any other, since the standard >> does it with no cycles to spare) uses the 12 bytes for the pointers plus >> one for temp storage. You can store the score data any way you like and >> set up the pointers during vblank. I'd probably recommend 3 bytes of BCD. > >Hmm, I'm still doing a wsync on each line... perhaps I should transfer >the source/binary over (a bit of a hassle, since it's on the 64) and >let you folks have a look. The standard does a wsync on each line too, but it uses every one of the other 71 available cycles. If we could get a look at your source, it'd be great. > It uses indirect indexed addressing, so it has to use LDA for the loads... >> for temp storage, STA zeropage / LDA zeropage is the same speed as >> TAX/TXS/TSX, with the added flexibility of letting the load be into any of >> the registers. > >No - tax/txs/tsx etc only take 2 cycles, while LD?/ST? zero page take 3. >This is why I used the stack pointer as the extra - saved one cycle... 3 instructions * 2 cycles = 2 instructions * 3 cycles, last I checked :) If you're somehow doing a LDX instead of LDA, the stack-pointer method is faster. >> Well, there's the old movable-sprite deal, if you haven't done that yet. > >You mean just a sprite moving around under joystick control? Yes, that >was my first program. I think it was for everyone, except me... I moved from "How to Draw a Playfield" straight into the early stages of INV, spending quite a while on playfield kernel before adding the players. >> multiple-sprite package. Or you could try to make your score routine into >> a movable 48-pixel sprite... if you can do that, we'll be groveling at your >> feet :) > >:) 48-pixel sprite, that can be positioned anywhere? :) I'll have to >try ;) If you can, we'll love you for life :) (Did anyone even get a 32-pixel movable sprite to work? With color changes? Using wsyncs?) -- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/stella.html Don't post pirate BINs to Stellalist. Be a programmer, not a pirate. Write the best game, win framed autographs of famous Atari alumni!!