Atari 2600 FPGA Progress...

ehenciak · February 5, 2005

Well, it's starting to look good!

Here are virtual screenshots of Pitfall and Video Pinball converted from TIFF to JPG using Gimp. Big thanks to Eric Crabill for his slick TIFF file generator. I'll be releasing a VHDL version of the TIFF file generator with Eric's permission once I know it's 100% as good as Eric's. It's close enough for now ! Both of these are the second or third frame of video.

I still have to add the missile and audio logic, but that's kitten play at this point after fighting the ball and player logic (well, audio will be a little tricky to get 100% right).

I need to make the design synchronous again since I ripped apart a few things debugging the player logic (no big deal...I have most of it done already). I was so suprised to see that a write to the player 1 graphics register causes the current Player 0 register to be stored in the "old" register. Vice-versa for Player 0 writes. I had it where player 0 writes sends the current player 0 sprite to the "old" register. What's sad is that I looked at the schematics for hours and simply didn't notice this since I'm a moron. Moreover, I knew I read this before, but I guess my friggin memory is going.

For what it's worth, when running Cosmic Ark, I see player 0's missile clock enable stay high for the starfield effect (hmotion "feature"...once I get the missile in there, I really hope I see the star effect in my screenshots.

At any rate, I'll do a webpage for this design once I get it 99% done (nothing is ever finished). It shouldn't be too long now. As always, this design WILL BE OPENSOURCED. You'd have to be either a criminal or selfish buffoon not to given all the hard work by others who make stuff like this possible (i.e. TIA schematics, the AWESOME z26 and Stella emulators for sanity checks, people on this list, Kevin Horton's Bankswitching document, piles of free documentation, free T65 core, MikeJ's debugging of T65 for Asteroids Dlx on a chip (now almost 100% accurate....I need to add the "forbidden opcodes" still)). Nothing like this would be possible without the above unless you have a ton of free time, a microprobing station, ability to use the force, or have some kind of spiritual communication path directly to Jay Miner.

I plan on making an affordable "kit" out of this when all is said and done. Like most collectors, I usually buy my stuff cheap at thrift stores. While I won't be able to make a kit for $1, I should be able to make it rather attractive price-wise ! Part of the fun of Atari game collecting is finding that Crazy Climber or Quadrun for $1 in a junk pile (I'm still waiting for that day) ! I don't want to make something that your average Joe like myself cannot justify spending a lot of cash on. I'd also like to see more people get hooked on FPGA design as well. It's friggin fun!

A long-term project of mine is making an opensourced library of hardware models of all Atari chips for synthesis. Maria's next once TIA's beaten.... ...more on that later. There are so many virtual Atari systems that could be designed !

This has been the best month ever coding this thing up . I've never had so much fun! I now see 100% why emulator authors spend hours on this type of stuff....it's an engineering high I cannot explain ! I know it's just Atari, but it's so much damn fun!

Again, all of this work will be opensourced. Even the kit will be opensourced (schematics, etc.) If you are currently working on an Atari VHDL model, please email me ! I'd release mine now, but I'd like to have a fully debugged version available since I am not too quick on answering emails unless it's the weekend....school and work interfere way too much with fun stuff like this!

Oh well, I need sleep...this is too much !

Ed

PS All the black regions of the screenshots are the overscan, vblank, etc. regions of the screen. Once this thing is driving a television, you will only see the visible portions of the screen !

Atari-Jess · February 5, 2005

Good to hear progress is going well!

*is excited about it*

I can't wait till its finished!

Flipper · March 19, 2005

I plan on making an affordable "kit" out of this when all is said and done. Like most collectors, I usually buy my stuff cheap at thrift stores. While I won't be able to make a kit for $1, I should be able to make it rather attractive price-wise ! Part of the fun of Atari game collecting is finding that Crazy Climber or Quadrun for $1 in a junk pile (I'm still waiting for that day) ! I don't want to make something that your average Joe like myself cannot justify spending a lot of cash on. I'd also like to see more people get hooked on FPGA design as well. It's friggin fun!

Oh, I agree. Being able to design "hardware" while still staying at the conceptual level rather than having to worry about "How much noise is on all these wires?" Or, "Why is it just sitting there letting out blue smoke." However, looking around the appropriate websites, it seems all the FPGAs are surface mount only. Or 1.8v. Or something else that doesn't work well for hooking an FPGA to a old console.

Are there any docs on prototyping in the modern world, pretty much dominated by companies who roll PCBs for each try because it's the only way to make your design work?