What kind of eproms do snes games use?

What kind of eproms do snes games use?
by endrien on 2009-10-03 (#51023)

What kind do they generally use? Is it just one chip you can solder in and it will work(Besides the games like starfox etc)?
Would I be able to program snes roms using this?
http://www.progshop.com/shop/programmer ... ammer.html
Edit: it says it supports EPROM (27, 27C, 87, ...)

by MottZilla on 2009-10-03 (#51025)

The SNES MaskROMs do not have a standard pinout. You can't just replace the chip and solder an EPROM in its place. You must rewire the board or rewrire the legs of the EPROM that don't match the SNES maskrom pinout. The largest 32pin EPROM suitable for the task is the 27C801 which is 1 MegaByte of storage. With relatively little rewiring you can solder it into the PCB's ROM socket. However for anything larger than that you have to start adding logic chips to decode things.

So before making any SNES cartridge changes you should ask yourself what your purpose is exactly. If you just want to play some of your ROMs on a real SNES, there are much better ways of doing that than building cartridges. Forinstance you can get a reprogrammable cartridge called a Flash Cartridge. There are two main ones for SNES now, the SuperFlash by Tototek ( http://www.tototek.com ) and the SNESFlash (I'm assuming) by MashMods ( http://www.mash-mods.com/products/snes ).

If you prefer something different you could always get a Backup Device/Cartridge Copier which is a large device that sits ontop of your SNES cartridge port and has a Floppy Disk drive and possibly a communications port on it to allow loading ROM images into memory in the device that allows you to play the ROM images on your console.

Costs will vary but the key thing is that if you just want to play alot of games you can make one investment to play any number of games you wish opposed to if you want to put EPROMs in cartridges, the costs will very quickly be much more than if you'd gone with a flash cartridge or other device. But in the end it's a matter of personal preference.

by endrien on 2009-10-04 (#51036)

How is this guy managing to pull this off?
http://www.youtube.com/watch?v=NokPAngb4EM

by koitsu on 2009-10-04 (#51040)

He re-wired the traces on the cart, as he stated in the video description here:

Quote:
Mask ROM chip was removed, and pinout slightly re-wired for compatibility with 27C080 8-Mbit EPROM chips. The 32-pin ZIF socket makes changing EPROMs easy.

How nice that he didn't disclose that in the video itself, resulting in mislead people such as yourself. But then again, given that his username is "Hentai" spelled backwards, why am I not surprised...

by endrien on 2009-10-04 (#51041)

koitsu wrote:
He re-wired the traces on the cart, as he stated in the video description here:

Quote:
Mask ROM chip was removed, and pinout slightly re-wired for compatibility with 27C080 8-Mbit EPROM chips. The 32-pin ZIF socket makes changing EPROMs easy.

How nice that he didn't disclose that in the video itself, resulting in mislead people such as yourself. But then again, given that his username is "Hentai" spelled backwards, why am I not surprised...

Is there any guide somewhere on how to make a snes cart work with eprom chips such as the 27C080
Where can I buy 27C080 eproms?

by MottZilla on 2009-10-04 (#51046)

You never did say what you are wanting to do. If you want to just play the games on your SNES, stay away from EPROMs. It's ALOT of work, it's expensive, and if you don't know what you are doing it's going to be alot worse. Instead, buy a Flash Cartridge which is a reprogrammable cartridge that is easy to use. Buy one here: http://www.tototek.com/store/index.php? ... ucts_id=39 or here: http://www.mash-mods.com/

Unless you only plan to play a very small number of games like 2 or 3 games, you'll spend way more with EPROMs than if you buy a Flash Cartridge.

by endrien on 2009-10-04 (#51052)

I just like messing around with electronics etc and it would be fun to make a few games, Why would it be extremely expensive for more then 2/3?

by tepples on 2009-10-04 (#51057)

For one thing, the manual labor of rewiring. Is your time worth $120, the price of a mash-mods flash card?

On the other hand, once you finish your games and you try to sell reproductions (like Frog Feast), the balance tilts back in favor of busting open old EA Sports carts for their PCBs and CICs if nothing else.

by MottZilla on 2009-10-04 (#51061)

If you buy a Flash Cartridge you will spend around $100 approximately. However if you build a cartridge with an EPROM, the first big expense is the EPROM programmer which depending on which one you get the costs can vary greatly. You might be able to get a fairly basic one for around $40 or so or a nicer one being maybe around $100, all the way to the really nice ones which could be $400 maybe even more.

Next, the typical EPROM people use for SNES games is the 8 megabit (1 megabyte) 8bit eprom. If a game is larger than that you have to use more eproms. That would be fine except that these chips are not super cheap. And I don't believe they are even manufactured anymore as they are obsolete components. But lets say you can get them for about $5 each. That's not too bad for smaller games. But many games are fairly large and will take 3 or 4 chips. So suddenly you could be spending $20 just on eproms for one game. You also need to provide yourself a sacrifice game to remove it's original rom from. Then you have misc costs of wire, solder, soldering tools.

So while if you are really efficient and only want to play a few games you might spend less than you would with a Flash Cartridge, you are still going to be putting alot of work into the few you do versus next to no effort with a Flash Cartridge. I'm just trying to make the point clear that if you want to play the games on your SNES, it really is a poor choice compared to a professional Flash Cartridge.

tepples wrote:
For one thing, the manual labor of rewiring. Is your time worth $120, the price of a mash-mods flash card?

On the other hand, once you finish your games and you try to sell reproductions (like Frog Feast), the balance tilts back in favor of busting open old EA Sports carts for their PCBs and CICs if nothing else.

I guess that depends on what "your games" means. I don't think he's planning on developing any SNES games so selling any cartridges would be naughty.