Checksums for EPROMs?

OldFoo · Post by **OldFoo** » Thu Aug 14, 2008 1:55 am

Does anyone have the checksums for the various NAOMI related EPROMs?

I'm looking for the checksums for the various BIOS chips as well as the EPROMs that are on each cartridge since these are items that are socketed and can be quickly verified on an EPROM programmer.

Thanks!

RJ

OldFoo · Post by **OldFoo** » Thu Aug 14, 2008 6:43 pm

If you have a programmer, you don't necessarily need the checksums. Download the dumped roms on the main website and use them to make a comparison and verify what you have. If there's a match, then the test will pass. Of course, this is assuming that you are referring to the BIOS roms on the system mobos.

OldFoo · Post by **OldFoo** » Thu Aug 14, 2008 8:53 pm

He is also talking about eproms on the carts themselves. This would be a great addition to the site, if we had a database of good checksums, and I am sure most people wouldnt mind running thru the test with their carts.

Channel - I am sure you are looking for a good resource for all or most carts, but if there is one or two you needed right away maybe post the names of those carts and someone could help out quickly in the meantime.

OldFoo · Post by **OldFoo** » Thu Aug 14, 2008 9:06 pm

i see that as a waste of time, as when you perform a cart check in the serice menu, what naomi does is a checksum test against the checksums of the ics stored in the cart, so you can be sure if your cart is ok or not

Alex

OldFoo · Post by **OldFoo** » Thu Aug 14, 2008 11:42 pm

Alveida wrote:I see that as a waste of time, as when you perform a cart check in the serice menu, what naomi does is a checksum test against the checksums of the ics stored in the cart, so you can be sure if your cart is ok or not

Alex

Here's a question about your statement:

A checksum will change if any part of the stored information is altered in any way. If you look at DOA2 and DOA2 Millenium, the hard coded information on the surface mount ROMs have not changed, but the BIOS is changed/updated to allow the new features. Why is it that this change does not cause an issue? Or, perhaps the checksum fails, but continues to run anyway since it is not system critical. :smt017

OldFoo · Post by **OldFoo** » Fri Aug 15, 2008 12:09 am

I have a cart that mulitple systems won't recognize. I figure if there's a list of checksums for the socketed EPROM on the cart then that's one quick thing to check off the list of items to look at.

Marvel vs. Capcom 2 is the cart I'm looking at. I thought I had it fixed but then it stopped working. System calls it an unknown cart. Doesn't appear to be a solder problem on the FPGA as I've reflowed those.

Does anyone have the checksum on that one?

OldFoo · Post by **OldFoo** » Fri Aug 15, 2008 12:11 am

I'd contact Ken @ irepairsega.com He could answer your question str8 off :smt020

OldFoo · Post by **OldFoo** » Fri Aug 15, 2008 4:51 am

joshua3dg wrote:
Alveida wrote:I see that as a waste of time, as when you perform a cart check in the serice menu, what naomi does is a checksum test against the checksums of the ics stored in the cart, so you can be sure if your cart is ok or not

Alex
Here's a question about your statement:

A checksum will change if any part of the stored information is altered in any way. If you look at DOA2 and DOA2 Millenium, the hard coded information on the surface mount ROMs have not changed, but the BIOS is changed/updated to allow the new features. Why is it that this change does not cause an issue? Or, perhaps the checksum fails, but continues to run anyway since it is not system critical. :smt017

If the BIOS on the Cart has the checksum, then it won't matter when the BIOS is changed, as the checksum will change along with it. If the checksum was stored on a chip on the cart (not BIOS) then I agree the checksum would be different.

I'm no expert on Naomi carts (or EPROMS in general) so I may be off the mark, but that would explain it.

OldFoo · Post by **OldFoo** » Fri Aug 15, 2008 7:23 am

dj_johnnyg wrote:
joshua3dg wrote:
Alveida wrote:I see that as a waste of time, as when you perform a cart check in the serice menu, what naomi does is a checksum test against the checksums of the ics stored in the cart, so you can be sure if your cart is ok or not

Alex
Here's a question about your statement:

A checksum will change if any part of the stored information is altered in any way. If you look at DOA2 and DOA2 Millenium, the hard coded information on the surface mount ROMs have not changed, but the BIOS is changed/updated to allow the new features. Why is it that this change does not cause an issue? Or, perhaps the checksum fails, but continues to run anyway since it is not system critical. :smt017

If the BIOS on the Cart has the checksum, then it won't matter when the BIOS is changed, as the checksum will change along with it. If the checksum was stored on a chip on the cart (not BIOS) then I agree the checksum would be different.

I'm no expert on Naomi carts (or EPROMS in general) so I may be off the mark, but that would explain it.

i wouldng explain it better ...

thats just how it works

OldFoo · Post by **OldFoo** » Mon Aug 18, 2008 4:30 pm

I really like the idea of also adding cartridge bios eprom dumps to this website to help people with possibly bad cartridge eproms.

As I do have an eprom programmer I'm happy to dump and contribute all the ones I have (below), and help out anyone else out who needs theirs dumped too.

Capcom vs SNK

Airline Pilots

Crazy Taxi

Death Crimson OX

F355 Challenge

house of the dead 2

zombie revenge

Wild riders (Naomi2)

RGP how about it? How can we coordinate this?