Subject: Re: [stella] Gravity Ball v015 - Thanks! From: R Mundschau <rmundsc@xxxxxxxxx> Date: Wed, 04 Jun 2003 11:23:57 -0500 |
> From: "Dennis Debro" <ddebro@xxxxxxxxxxxxx> > Reply-To: stella@xxxxxxxxxxx > Date: Wed, 4 Jun 2003 06:30:10 -0400 > To: <stella@xxxxxxxxxxx> > Subject: RE: [stella] Gravity Ball v015 - Thanks! > > Hi Rob, > > I've got one more (sorry I didn't see this before). You're doing 30 scan > lines for overscan. Then before doing vertical sync you do one more > WSYNC. This gives you 263 scan lines. This is okay as most TVs should > show this fine. > > I'd suggest your vertical sync to be... > > LDX #44 > LDA #02 > STA WSYNC ; sync with end of last line of overscan from previous > frame. > STA VSYNC ; Enable vsync (happens at the beginning of the scan line) > LSR ; a now 0 saves a byte too--right Thomas ;) > STA WSYNC ; vsync for 2 scanlines > STA WSYNC > STA WSYNC > STA VSYNC ; end VSYNC (happens at the beginning of the scan line) > STX TIM64T > > Then in overscan, reduce the scan line loop to 29. > > Having VSYNC happen at the beginning of the scan line will guarantee > that even the sensitive 2600 (mainly jr's) will play the game fine. I > think Eric Ball did some research on this a while back. It's just one of > those "safe" things to do :) Thanks for the tip! One of the lingering questions I have had about the TIA is when do I need to set VSYNC to have it count for a whole scanline. Then, when to turn it off so as to get exactly 3 lines of VSYNC and not 2 or 4. I will use your code suggestion. Thanks Rob ---------------------------------------------------------------------------------------------- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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