Cybernoid Posted March 18, 2004 Share Posted March 18, 2004 Hmmm, I have a couple of questions for the gurus regarding PM graphics and priority. While, messing with PM graphics and an emulator, I have noticed that if I disable the PM graphics DMA and write directly to the Graphics registers (0xd00d-0xd011) AND turn priority off (0xd01b = 0), then a few weird things happen. In Antic E mode, Players 2 and 3 and all Missile colors are ORed with the Playfield colors. Player 0 and 1 seem to be on top (higher priority) of some of the Playfield colors, but not all of them. So Player 0 and 1 colors are ORed with some Playfield colors, but I haven't figured out which ones yet. I haven't noticed this Playfield/PM color ORing with the DMA turned on. I was wondering if anyone out there has messed with this and knows exactly what happens in this priority-0 mode. Does anyone know how Player/Playfield colors are ORed? Thanks, Chris Quote Link to comment Share on other sites More sharing options...
Cybernoid Posted March 18, 2004 Author Share Posted March 18, 2004 Also, the reason why I am asking is I am working on a 8bit application and a game in my spare time, and it looks like in Antic E mode, you can have: 4 colors (one for each playfield) plus 5 colors (one for each player/missile) But, for each line, if you can OR each player with each playfield color, you can have a total of 20 colors per line, but dependent on player position. Is this right? Thanks, Chris Quote Link to comment Share on other sites More sharing options...
emkay Posted March 18, 2004 Share Posted March 18, 2004 But, for each line, if you can OR each player with each playfield color, you can have a total of 20 colors per line, but dependent on player position. Is this right? It would be nice if it is so... but You have only 2 players(plus missiles) that are usable with 2 playfield colors for this. Quote Link to comment Share on other sites More sharing options...
Bryan Posted March 18, 2004 Share Posted March 18, 2004 I haven't noticed this Playfield/PM color ORing with the DMA turned on. http://www.atariage.com/forums/viewtopic.p...r=asc&start=110 Here's a message I posted on this. I believe it happens whether DMA is on or off. -Bry Quote Link to comment Share on other sites More sharing options...
Cybernoid Posted March 18, 2004 Author Share Posted March 18, 2004 Ah, thanks. I seem to be getting different results with DMA off versus DMA on, but that could just be my stupidity in doing something wrong. Oh well, thanks for all the information! I think I will mess with this a little more anyway...It does make some interest effects. Cheers, Chris Quote Link to comment Share on other sites More sharing options...
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