Heaven/TQA Posted June 4, 2014 Share Posted June 4, 2014 when I am reading the docs correctly it is possible to have code running in RAM bank #0 at $4000 while ANTIC displays gfx at BASE RAM at $4000? and can I even put display lists there? (as ANTIC runs here as co-processor)? GTIA sprites would be not as GTIA has not such kind of logic and control register $d301? right? Quote Link to comment Share on other sites More sharing options...
Bryan Posted June 4, 2014 Share Posted June 4, 2014 All DMA is done by Antic so PMG's are no different than playfield. Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted June 4, 2014 Author Share Posted June 4, 2014 now that's get more and more interesting... ANTIC can be set to read from BANK or BASE, same with CPU... and more interesting if I can put even PMG in banks... Quote Link to comment Share on other sites More sharing options...
Creature XL Posted June 5, 2014 Share Posted June 5, 2014 You should be aware that not all RAM expansions support this. Quote Link to comment Share on other sites More sharing options...
Bryan Posted June 5, 2014 Share Posted June 5, 2014 You should be aware that not all RAM expansions support this. Do any of them support it? Quote Link to comment Share on other sites More sharing options...
Creature XL Posted June 5, 2014 Share Posted June 5, 2014 Do any of them support it? I think so. At least the Compy-Shop expansion I have AFAIK. haven't tested it. It's a pitty that no all support it. When you think about it, it's a bit like the C64's VIC-II can access a 16Kb area anywhere in its 64K. Guess that could solve some memory problems we face on the 8-Bit. for example PMG (>1k) char-screen (1k) each charset (1k). When using hi-res screen (8k) and double buffering for free. You do not even have to change the rendering routine because it always writes in teh $4000-$7fff area However, I think when using SW sprites its not that cool. But haven't thought about that. i hope Heaven has more (cooler) ideas Quote Link to comment Share on other sites More sharing options...
Bryan Posted June 5, 2014 Share Posted June 5, 2014 The A8 would benefit from a better banking scheme. Too late I guess. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted June 5, 2014 Share Posted June 5, 2014 (edited) The A8 would benefit from a better banking scheme. Too late I guess. True on both counts. It would be nice to keep frame buffers in extended RAM, but the completely inflexible Antic/CPU banking system makes it impossible in most situations. And once you get past half a meg that functionality's gone anyway. Even the fact the banking window is fixed at $4000-$7FFF is limiting. Edited June 5, 2014 by flashjazzcat 1 Quote Link to comment Share on other sites More sharing options...
+bob1200xl Posted June 6, 2014 Share Posted June 6, 2014 Would linear memory in a 65816 be more useful? You can even access upper memory banks when you are in 6502 mode. How modular is most code? Would it be a major task to convert some of the routines to linear memory access? Bob Quote Link to comment Share on other sites More sharing options...
Kylev Posted June 6, 2014 Share Posted June 6, 2014 The Newell 256k upgrade supported the separate access for ANTIC and the CPU. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted June 6, 2014 Share Posted June 6, 2014 (edited) Would linear memory in a 65816 be more useful? You can even access upper memory banks when you are in 6502 mode. How modular is most code? Would it be a major task to convert some of the routines to linear memory access? Is this meant for me? Yeah - linear memory access would be very convenient, as would be four times the stock CPU speed. But what I'm writing needs to work with non-specialised hardware (i.e. stock machines with at least 128K, or most people's base configuration). Edited June 6, 2014 by flashjazzcat Quote Link to comment Share on other sites More sharing options...
+bob1200xl Posted June 6, 2014 Share Posted June 6, 2014 FJC: The question is: how difficult is it to add linear support? Not for every routine, but some of the mandatory ones. At some point in the code does a tiny kernel actually do the access - one that most everyone uses? Bob Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted June 6, 2014 Share Posted June 6, 2014 The banks can be "unrolled" relatively easily, so I suppose at length something could be done to take advantage of linear RAM. The cartridge code depends on direct access to extended RAM... hence the cartridge. Quote Link to comment Share on other sites More sharing options...
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