Hi, Do you patch the original game and make a repro? It depends from a lot thing: - If you use an original super nintendo PCB game as donor (Hi-Rom + 64k Sram + battery, original game uses a SHVC-1J3M) you won't be able to use a 27C322 as is. If I'm correct, this Eeprom is a "Word-wide" (2Mb*16bit) and cannot be configure as a "Byte-wide" (4Mb*8bit). In order to decode the 16bit addresses, you'll need two 74LS245 and a 74LS139 and use them as a decoder. If you want to use an original PCB, the best solution is to used a 29F032B TSOP on a TSOP40-DIP36 adapter. But this chip is getting rare this day and quite expensive. Also, your conversion have to stay under 4mb. If your file is bigger it's still possible but it's getting a bit more complex. - The best solution for whatever your needs are is to check on http://www.retrostage.net/, the guy is making new SNES PCB and you can use new parts and 27C322. He also did a PCB for games up to 12Mb (like Star Ocean uncompressed, or Crimson Echoes, Tales of Phantasia, Dragon Quest 3, etc.). Cheers,
Purely out of curiosity: what do you intend to do in your conversion? (Is it a mod of Chrono Trigger, a different game entirely, etc.?)
Well I own a jap version and I want to convert it to English. I am trying to find a wiring diagram for the 28c322 but the only one I could find is this one http://sega4ever.power-heberg.com/t...es/sh%E9ma%2027c322%20%20in%20Snes%20cart.png But I see that pin 22 on the 27c422 wich is vcc is not connected. Any suggestions?
Just to nitpick your link, it states: Yes, a 8mb chip only comes in 8mb. The 801 in the name is basically saying its 8mb. There are 4mb versions with same pinout (with obviously 1 less address line) for example, the 27c4001 (which only comes in 4mb! ;-)) Also, in your eprom stacking part of the guide, if you are going to stack more than 1 chip, you might as well use a 27C160 as you are soldering a bunch of wires anyway, may as well use a chip that is 16mb and only need 2 of them. Or you could just the tsop to dip36 adapter we are already talking about in this thread - 32mb chip and only need one of them, no multiplexer required.
OK, thanks for the info. I am not an expert on these matters but I wrote a guide that describes how I managed to get it to work. To be honest, I wasn't even aware of the 16Mb package so maybe I'll update my guide in the future Does the 27c160 have the same pinout at the 801? I haven't seen anyone else mention the 16Mb chip on other forums.
No, it doesnt have the same pinout as the 27C801, which is why I only suggested it if you are stacking more than 1 chip (i.e. 3+ chips by putting more chips at the top of the cart and running wires to it). If you only need 16mb for your rom, stacking the 27C801 is the best way. If you need 32mb and dont want to use the tsop adapter, id probably just put 2x 27c160 at the top of the cart and run wires. Only need 2 chips this way. But using the TSOP adapter is probably the best way, gives you 32mb and only one chip and is directly compatible pinout to the original maskrom (so no wires at all)
OK cool, that's interesting I'll have to give it a go one afternoon And yes, I agree the TSOP is the best method for sure, it's just not so beginner-friendly with the surface-mount soldering and stuff. It's also on my list of to-do's though. Thanks for your help
You can buy them already mounted to the pcb, you can also get an adapter that will program it with a tl866 while it's mounted to the pcb. It's the best way to do it really.
But that takes all the fun out, surely? /s I'll keep an eye out for those, that would make some of my repro's a bit less work!
Okay guys I've hit a snag my chrono trigger has a current pcb that the one on ones central it has this one http://www.snescentral.com/pcbboards.php?chip=SHVC-BJ3M-20 Instead of this one http://www.snescentral.com/pcbboards.php?chip=SHVC-1J3M-20 The board I have has two mask roms I only have a single 27c322. Do I wire it two the first mask rom and ignore the second? I already have the 74245 and the 74139 ic
Oops sorry for the typo the PCB on my chrono trigger is different from the one on snes central mine has two mask roms, the one on snes central has only one. My question is can I use a single 27c322?Wire it to the first mask ROM and ignore the second one? I have seen people do it with tsop but don't know if it can be done with 27c322.
