Need to dump some protos...

[Nicola]

Hi!
Is it possible to dump protos (with EPROM) using backup units like this one for gb?

http://www.easybuy2000.com/store/nintendo%20accessories/emerger.shtml#features

I need to dump protos for genesis, nes and gb but I don't want to risk using an EPROM programmer without any knowledge

[DogP]

Hmm... it looks like you could probably dump your gameboy ones with that... it may be possible to stick the other carts' EPROMs in the GB cart and dump them, but only if they're the same type of chips (or same/close pinouts). I'd personally recommend using an EPROM reader though (assuming all the EPROMs are removable), since there's no extra circuitry involved in dumping a chip the way it's supposed to be done. It's also cheaper, and really, they're not difficult to use. If you need someone to dump them, I can do that for you, as long as all of the EPROMs are removable. And I dunno if you have checked yet, but some/all of the protos might have already been dumped, so you might not need to dump them.

DogP

[Nicola]

Thanks a lot! I must learn how to use an EPROM reader.

I have a genesis proto with EPROM soldered...
How may I dump it?

[DogP]

Hmm... if you have a proto with a soldered EPROM, that's a little more difficult. What you'd need to do with that is to get the pinout ( http://www.gamesx.com/cartouts/gennycart.htm ), and make an adapter to go from the edge of the cart to a the same pinout that can plug into an EPROM reader (it's kinda a pain). That is, assuming that there's no extra chips involved like an MMC chip or other memory controllers. For the Genesis one, I'd personally try to find someone with a genesis cart dumper already built, unless you're good at this kinda thing.

Or... you can desolder the EPROM, dump it, then solder it back in, or the smart way, solder a socket and just put the chip in that, although I REALLY doubt you'd want to do that :P .

DogP

[Nicola]

Thanks!

[ragtime_tgs]

genesis has a 16bit data bus on the cartridge interface.
most cheap eprom programmers can only handle 8bit without some selfmade interface.
afaik most genesis protos use 2 normal 8bit eproms,one for d0-d7 and one
for d8-d15,both eproms accessed at the same time form a 16bit data bus.
that means the rom image is interleaved,all the odd bytes are on one eprom,and all even bytes are on the other one.
the easiest way is to dump them one after another and then find a program that can merge interleaved split files.

[slapdash]

There used to be these things called "chip clips", IIRC, which are made to clip onto the top of chips of certain sizes. I don't recall their exact purpose, so you might need to do some customization, but the idea is you could just clip this onto the chip and read from there without desoldering.

[DogP]

genesis has a 16bit data bus on the cartridge interface.
most cheap eprom programmers can only handle 8bit without some selfmade interface.
afaik most genesis protos use 2 normal 8bit eproms,one for d0-d7 and one
for d8-d15,both eproms accessed at the same time form a 16bit data bus.
that means the rom image is interleaved,all the odd bytes are on one eprom,and all even bytes are on the other one.
the easiest way is to dump them one after another and then find a program that can merge interleaved split files.

Yup... that's exactly how you do it... just dump D0-D7, then dump D8-D15. I've written a program to combine the even/odd bytes, and also split a ROM into even/odd bytes to be burned to the cart. The app is at http://dogp.home.comcast.net/CPP/bintool.zip .

And the problem with dumping a chip while it's in circuit is that you have to make sure that nothing else will interfere with the reading. Like if you have SRAM on the cart, you have to make sure that the SRAM is disabled so it won't try outputting it's data to the line at the same time, along with just normal electrical interference that other devices might cause.

DogP