CPUWIZ Posted December 31, 2013 Share Posted December 31, 2013 And with this, the year is over. Here is a quick and dirty demo, that shows a 256K bankswitched ROM (14 banks @ $8000, last bank @ $C000), with dual banked RAM @ $4000 (2 x 16K). I attached some screenshots of the rough outline of the code, that demo's this. Also a picture of the configured board, to make this work. Happy New Year! 8 Quote Link to comment Share on other sites More sharing options...
jetset Posted December 31, 2013 Share Posted December 31, 2013 I'd like to buy one of these games on cart if they become available. What is it? 1 Quote Link to comment Share on other sites More sharing options...
Trebor Posted December 31, 2013 Share Posted December 31, 2013 Happy New Year! Happy New Year, indeed, and a very heartfelt thank you! Working on these (Mega)cart boards for the hardware end, Curt finishing up the XM work, Bob going to town on the software end with Astro Blaster already out the gate and no doubt other developers working on games, we have very much to look forward to and be happy about in the 7800 community in 2014. It is all greatly appreciated. 3 Quote Link to comment Share on other sites More sharing options...
Trebor Posted December 31, 2013 Share Posted December 31, 2013 What is it? The hope and potential of developing and distribute some of the greatest games to ever grace the 7800. 1 Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted January 1, 2014 Author Share Posted January 1, 2014 The hope and potential of developing and distribute some of the greatest games to ever grace the 7800. Yes, more people other than Bob should go for it. If anyone is serious about developing even a tech-demo for this new board, send me a PM and I'll supply you with a test board. I just programmed a 64K EPROM, with the first byte of each 16K bank, set to $AA through $DD. Programmed dual bankswitch PLD code for it and mostly finished putting together my development board (jumper, switch etc.). Every 128 frames, the secondary bank number increments and wraps after 3, the first byte of the secondary bank is read and displayed next to the current bank number of the main EPROM (256K in this case). Take that, emulators! P.S. The VersaBoard will be able to do 256K + Bankswitched RAM (2 x 16K) + POKEY, at the same time. 4 Quote Link to comment Share on other sites More sharing options...
+Allan Posted January 1, 2014 Share Posted January 1, 2014 Wow. That's fantastic. Speaking of RAM... could the 7800 address 64K RAM if Atari had wanted to add more way back 1984? I know the 2600 has the 6507 which can only address 128 bytes of RAM but the 7800 has the same CPU as the 8-bit computers. Allan Quote Link to comment Share on other sites More sharing options...
jaybird3rd Posted January 1, 2014 Share Posted January 1, 2014 Take that, emulators! Yes! Isn't it great when you get the original hardware to do something totally new, something that you know the emulators won't catch up with anytime soon? That really adds new life to these old systems, even more so than writing new software (although that's certainly important). Congratulations on implementing the bankswitched RAM in particular: I know that was a tough one, and as I've said before, it always bugged me that Atari's old boards only used 16K out of a 32K SRAM. 2014 is shaping up to be a good year for the 7800! Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted January 1, 2014 Author Share Posted January 1, 2014 Wow. That's fantastic. Speaking of RAM... could the 7800 address 64K RAM if Atari had wanted to add more way back 1984? I know the 2600 has the 6507 which can only address 128 bytes of RAM but the 7800 has the same CPU as the 8-bit computers. Allan Technically, the 6502 can address 64K, but that leaves no room for anything. Could you bankswitch more RAM, probably? In a linear fashion, Atari could have made a 16K ROM game with 32K RAM. Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted January 1, 2014 Author Share Posted January 1, 2014 Yes! Isn't it great when you get the original hardware to do something totally new, something that you know the emulators won't catch up with anytime soon? That really adds new life to these old systems, even more so than writing new software (although that's certainly important). Congratulations on implementing the bankswitched RAM in particular: I know that was a tough one, and as I've said before, it always bugged me that Atari's old boards only used 16K out of a 32K SRAM. 2014 is shaping up to be a good year for the 7800! Thanks Jay, I appreciate it. Sorry about bugging you with the RAM crap. LOL 1 Quote Link to comment Share on other sites More sharing options...
jaybird3rd Posted January 1, 2014 Share Posted January 1, 2014 Thanks Jay, I appreciate it. Sorry about bugging you with the RAM crap. LOL No problem! I just hope I was helpful in some way. I'm looking forward to trying the new boards! 1 Quote Link to comment Share on other sites More sharing options...
jetset Posted January 1, 2014 Share Posted January 1, 2014 I often wonder if some of you guys are geniuses with the shit you do. Or am I just a tech-dimwit? Don't answer that. Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted January 1, 2014 Author Share Posted January 1, 2014 No problem! I just hope I was helpful in some way. I'm looking forward to trying the new boards! You did nudge me to try the EPROM instead, which was useful. Me using the broken RAM chip to test bankswitching, was my 2013 #1 FAIL. Hmm, well, maybe the broken 1MB support on the MGP was. LOL I'll send you one of each, when the new one comes in. 1 Quote Link to comment Share on other sites More sharing options...
Lynxpro Posted January 1, 2014 Share Posted January 1, 2014 Hmmm...what's the next challenge? Adding more than 32K RAM to a 5200 cartridge? Quote Link to comment Share on other sites More sharing options...
The Usotsuki Posted January 1, 2014 Share Posted January 1, 2014 16K ROM and 32K RAM would be excellent for my purposes, actually xD The BASIC I use takes about 10K ROM plus system support code. with a little trimming, it might be possible to fit a small operating system, or a bootstrap and hooks, in 16K, and still have plenty of RAM for loadable code. If the ROM itself had support to do OS functions over something like the XM's SIO...even just load/save/bload/bsave, with a separate program for other OS functionality...and contiguous RAM is important, which the XM doesn't provide a lot of. Quote Link to comment Share on other sites More sharing options...
Jaynz Posted January 1, 2014 Share Posted January 1, 2014 Oh, oh! SID chip! SID chip! 1 Quote Link to comment Share on other sites More sharing options...
PacManPlus Posted January 1, 2014 Share Posted January 1, 2014 Awesome, awesome, awesome! Looking forward to getting my hands on these 6 Quote Link to comment Share on other sites More sharing options...
bennybingo Posted January 1, 2014 Share Posted January 1, 2014 Awesome, awesome, awesome! Looking forward to getting my hands on these So are we! (Of course, I meant to say that we all are looking forward to YOU getting YOUR hands on these! ) 2 Quote Link to comment Share on other sites More sharing options...
Lynxpro Posted January 1, 2014 Share Posted January 1, 2014 Oh, oh! SID chip! SID chip! An Amiga Paula chip would be more appropriate since Atari Inc paid for its development. I could imagine Atari Inc later using both the Paula and AMY chips in later 7800 games... Quote Link to comment Share on other sites More sharing options...
YANDMAN Posted January 1, 2014 Share Posted January 1, 2014 Is this the bit where one of the many talented programmers in the midst makes a Zelda esque game for our beloved system is it is it 1 Quote Link to comment Share on other sites More sharing options...
Jaynz Posted January 1, 2014 Share Posted January 1, 2014 Lynxpro, I know.. I just love the SID chip. 1 Quote Link to comment Share on other sites More sharing options...
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