Subject: Re: [stella] Positioning two objects From: "Andrew Davie" <adavie@xxxxxxxxxxxxxxxxx> Date: Fri, 15 May 1998 13:55:02 +1000 |
Nice idea, Erik. How about using a single zero page routine which, for delays, farms it out to an external routine (JSR delayn). The self modification would be to WHICH routine. Have a whole bunch of routines delay1 delay2 delay3 delay4 which simply delay that many cycles. OK, you add on 12 for the JSR/RTS, or you could REALLY hardwire it and have it JMP delayn and JMP back, for 8 cycles total. The point is, you would only have the single scanline routine, it would be quite short, and could fit in zero page. The self-modification part would simply be the low byte (if we organised it properly) of the routine to which we're vectoring. I haven't figured the feasibility in entirety, but seems eminently possible to me. Cheers A >Make sense? Might it work? You'd need enough RAM to hold the generated >kernel for every time you want to position two objects together, probably >about 30 bytes per pair, which kills any chance of zeropage. But SC or >megacart RAM could hold the 300-450 bytes for this. And three objects on a >line can't be done if they're all in the same position, but if they can be >forced far enough apart, it could be done. -- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/stella.html
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