Subject: Re: [stella] Thin Red Line bugs From: Thomas Jentzsch <tjentzsch@xxxxxx> Date: Sun, 18 Aug 2002 20:14:00 +0200 |
Rodrigo wrote > althought I think #$40 or #$42 is more appropriate) Yup, red is $4x. > STA ENAM0 ; Btw, is it ok to enable an object even before the > ; 1st Vsync? Should be no problem. And the object is invisible as long as VBLANK is active. > LDA #2 > STA VBLANK > STA VSYNC > STA WSYNC > STA WSYNC > STA WSYNC > LDA #0 > STA VSYNC That code might not work on a real VCS, because it might doing lesss than 3 VSYNCed lines, if the first WSYNC is happening a bit late in that line. > LDX #37 ; Set the loop counter: 37 vertical blank lines >VBlankLoop > DEX ; DEX is the 1st statement of the loop, so loop counter > STA WSYNC ; ranges from 36 to 0, which i think is a good > BNE VBlankLoop ; convention. Btw, is it? Sure. Or you can loop down to -1, which is sometimes easier to code (e.g. for table access). > Btw, Im aware that a HMOVE must >; be *immediatly* after a WSYNC, but... being just a single BNE > apart could be considered "immediatly after" ? IIRC no, that already will change the positioning. There are some tricks you can do with HMOVE (search the archives for "weird;HMOVE"), but as a beginner you should always position it *directly* after a WSYNC. Have fun! Thomas ---------------------------------------------------------------------------------------------- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
[stella] More CC info, Glenn Saunders | Thread | Re: [stella] Thin Red Line bugs, KirkIsrael |
Re: [stella] PCAE has 263 Scanlines, Paul Slocum | Date | Re: [stella] PCAE has 263 Scanlines, Thomas Jentzsch |
Month |