[GUIDE] Make a Reprogrammable Genesis Cart

[SUPERABOBO]

Nothing to worry about. All of the cart technologies are the same from cart to cart. As Zorlon said, all of the region checking will occur in your console itself.

Great stuff. That also makes hunting for donor carts much easier too

Do Genesis roms not have any headers that need removing before programming like SNES roms?
Does it matter what format the file is in? Is .Bin fine?

Thanks again for your help.

[Jazzmarazz]

Great stuff. That also makes hunting for donor carts much easier too

Do Genesis roms not have any headers that need removing before programming like SNES roms?
Does it matter what format the file is in? Is .Bin fine?

Thanks again for your help.

No stripping required. The Genesis actually requires the "header" to be present since it checks for the SEGA string.
Just be careful with MD/SM/BIN converters. They make modifications specially for emulators and could render the ROM file unplayable on real hardware. I prefer BIN format.

[SUPERABOBO]

No stripping required. The Genesis actually requires the "header" to be present since it checks for the SEGA string.
Just be careful with MD/SM/BIN converters. They make modifications specially for emulators and could render the ROM file unplayable on real hardware. I prefer BIN format.

Ah nice, Good to know.

Is it best pad out a rom to fill out the Eprom?

Looking at Panorama Cotton which is 2.5MB, should I pad it to 4MB to fill a 27C322, or does it not matter?

[Jazzmarazz]

Ah nice, Good to know.

Is it best pad out a rom to fill out the Eprom?

Looking at Panorama Cotton which is 2.5MB, should I pad it to 4MB to fill a 27C322, or does it not matter?

Short answer, no; only if you want to.
Long answer, : the Genesis, unlike the gameboy, does not read every byte to create a checksum of sorts. Granted you have all of the addressing pins on your Eprom connected to an output, those bytes will never be accessed, so the data is unimportant.

[SUPERABOBO]

Short answer, no; only if you want to.
Long answer, : the Genesis, unlike the gameboy, does not read every byte to create a checksum of sorts. Granted you have all of the addressing pins on your Eprom connected to an output, those bytes will never be accessed, so the data is unimportant.

Well thats a switch. I'm that used to padding roms for NES and SNES I thought Gen games would need padding also.

Thanks for your help, dude.

Having some problems programming 27c322 chips. 27c160 programmed no problem, the 322's seem to program ok yet gives me an error when they try to verify. But yet looking at the data buffer it seems like they programmed ok? Really strange.

Everything is setup correctly, dip settings, jumpers, the lot. Only thing I can think of is that maybe it's the AC adaptor, just checked it and it's 9V. Using the same software as you btw.

[Jazzmarazz]

Well thats a switch. I'm that used to padding roms for NES and SNES I thought Gen games would need padding also.

Thanks for your help, dude.

Having some problems programming 27c322 chips. 27c160 programmed no problem, the 322's seem to program ok yet gives me an error when they try to verify. But yet looking at the data buffer it seems like they programmed ok? Really strange.

Everything is setup correctly, dip settings, jumpers, the lot. Only thing I can think of is that maybe it's the AC adaptor, just checked it and it's 9V. Using the same software as you btw.

Im sure you did everything correctly, the problem is the programmer itself. I for example, never got a 322 programmed successfully. The Willem does a few things well, and other things terribly. If you plan to do this much more often, I suggest buying a different programmer. GQ programmer or Willem "True-USB" are apparently much better than the Parallel programmers. I wish I could sell mine and buy a more expensive one.

hIt seems like half of my 1MByte 16-bit eproms burn correctly and 0% of the larger ones program successfully. When programming 8-bit eproms, all work perfectly well. It is just that your programmer is cheap. :/

[SUPERABOBO]

Im sure you did everything correctly, the problem is the programmer itself. I for example, never got a 322 programmed successfully. The Willem does a few things well, and other things terribly. If you plan to do this much more often, I suggest buying a different programmer. GQ programmer or Willem "True-USB" are apparently much better than the Parallel programmers. I wish I could sell mine and buy a more expensive one.

hIt seems like half of my 1MByte 16-bit eproms burn correctly and 0% of the larger ones program successfully. When programming 8-bit eproms, all work perfectly well. It is just that your programmer is cheap. :/

Yep, the programmer is complete junk and so is the software.
I bought the Willem as it was the only programmer I could find that had a 16-bit 42dip adaptor. I usually use my Genius G540 for programming NES and SNES eproms, it has never never failed me once, but sadly it doesn't support 16-bit 42dip Eproms. After hours of messing I managed to get only a few 27c322's programmed with the Willem. The settings are all correct yet it seems total hit or miss if it programs or not. I have not had any problems with 27c160 eproms so far.

The verify step after programming is also completely useless. A chip will fail to verify, remove it and pop it back in and it will suddenly verify without any errors.

The GQ's are very expensive but seem like they are worth looking into as the Sivava Willems are complete junk.