I've attached an image of a Sega Saturn cartridge PCB. I ordered a set of these and will dump the ROMs when they arrive, but in the meantime would like to figure out what they are for.
The carts have one DIP 512Kx8 flash memory chip. This seems like an unusual choice considering all Sega Saturn cartridges I've looked at use QFP or SOIC mask ROMs exclusively. None of the flash chips have a Sega standard part number printed on the top or on the label, so maybe it's for 3rd party use?
I'd guess it's a data only cartridge. Given the small size, perhaps for an earlier Saturn game like Ultraman? Or did that game use a 1MB/2MB ROM cart?
EDIT:
I bet the test pads set the 8-bit cartridge ID number, which is gated by the 74LS244 onto the data bus when the ID area is read. The 74LS00 probably does the decoding between the ROM area and ID area. Well, 4 bits but I think all the ID's are spread across bits in a byte like $5A and $58.
The carts have one DIP 512Kx8 flash memory chip. This seems like an unusual choice considering all Sega Saturn cartridges I've looked at use QFP or SOIC mask ROMs exclusively. None of the flash chips have a Sega standard part number printed on the top or on the label, so maybe it's for 3rd party use?
I'd guess it's a data only cartridge. Given the small size, perhaps for an earlier Saturn game like Ultraman? Or did that game use a 1MB/2MB ROM cart?
EDIT:
I bet the test pads set the 8-bit cartridge ID number, which is gated by the 74LS244 onto the data bus when the ID area is read. The 74LS00 probably does the decoding between the ROM area and ID area. Well, 4 bits but I think all the ID's are spread across bits in a byte like $5A and $58.