Thursday, January 22, 2009

Prototype Success!

It works!
If only I knew more 1992 pop culture trivia! Maybe then I could actually enjoy playing this game.

You can see a picture of my setup here. It's the cannibalized Pinocchio cart. I desoldered the mask rom ic, and replaced it with a socket. The socket has some wires that connect to a ribbon cable, which connects to the DE2 board. The DE2 board maps the on-board SRAM to the rom socket on the cart. The board loads the ROM data from the SD card into the SRAM when it turns on. Then, when you turn on the SNES, it can play the game that was loaded from the SD card.

There's so much stuff I want to add! I think now that I've proven it can work, I'll start working on making a pcb and building a self contained version. Then i can start adding cool features like support for as many games as you can fit on the sd card, special chip emulation, and who knows what else...


  1. Awesome. Let me know when I can come play Killer Instinct on it.

  2. nice work, i'm personally opting for the FPGA spartan 3an..

    nice board.. en pretty ok with the price.. (even has a mini sd addon ;))
    i would also like to recommend you to look at some emulators..

    they usually have great code where to look for what kind of Sram they use.. CRC check etc etC..

    and ofcourse the nice things like fx emulating..

  3. @Icekiller i haven't done anything with the savegames or special chips yet, but I have glanced over emulator source thinking about this stuff.

    you will notice that pinocchio (the cart i used) is a hirom game, and that jeopardy is a lorom game, so i do have some grasp on the mapping.

    i'm delaying a lot of the more advanced stuff while i work on my new pcb for this project.

    as far as the altera vs xilinx choice, for me, i'm just using what was available in my lab. it has an sd card slot already on the board as well, which is nice.

  4. @scottjg don't know if you can see my mail.. but drop me a line..

    i'll give you some info on how to also be able to use this stuff to make it for nintendo64 ;)

  5. @IceKiller i can't see e-mails on blogspot but feel free to e-mail me: scottsnes at

  6. Looking forward to your progress on this. Especially the talk about the possibility to upload via USB makes me all tingly.

    I currently test my code by uploading it to Tototec's card. And while it is a fine card, unplugging the cart from the SNES, putting it in the programmer and program it via Parallell cable and then reinsering it in the SNES is getting old.

  7. Very cool!
    Is it able to run "Super fx" games ok? (like star fox or stunt-race fx)
    It seems we share a likeing for messing with old systems. :)

  8. Yet another comment from me :)
    Is it possible to post some sort of tutorial for this? (even if its vague as hell :P )
    I would love to try this out. Also, still wondering about SuperFX games.

  9. hmm no superfx support yet. it could be added though, if i could figure out how to code it on the fpga. i don't think it's too farfetched, i just need time to do it.

    in terms of a tutorial? i'm not sure it would be useful. the de2 board is like 250$, and the sram (512kb) isn't even big enough to play most games. it would make more sense to buy a flash cart from tototek?

  10. 250$! YIKES!
    Maybe ill stick with emulation for a bit :)

  11. I notice that you're using the DE2, which has a Cyclone II FPGA, which uses 3.3V IO, but you have no voltage translators in between the board and the SNES. Can the SNES actually use 3.3V logic? I recently tried building a cartridge reader with my DE1, but I couldn't get any ROM readbacks to work, and I'm currently attributing it to the SNES needing 5V logic. If you found a way around this, let me know! :)