I have a rather strange 32-pin 128KB EEPROM that strangely seems to already conform to the pinout of a 28-pin NES MaskROM. It contains an unreleased prototype that I would like to put into a cartridge to make it work. FWIW, it has already been dumped, but I want to get the original chip running in a donor board.
Once again, this particular EEPROM (Toshiba TC571001D-15) is NOT the standard pinout. In fact, the datasheet implies that it was designed for 28-pin MaskROM compatibility even though it's a 32-pin chip:http://www.datasheets360.com/pdf/1585995656965978174
The final retail game is 28-pin 128KB so I checked the pinout against the 28-pin 128KB PRG chip here:http://nesdev.com/NES%20ROM%20Pinouts.txt
It matches up except that Vcc is labeled NC on the Toshiba chip. Expecting to find a 28-pin chip in my donor cartridge (same PCB), I found a 32-pin chip instead. Because my chip is already 32-pin, I compared this pinout as well. I see that pins 30, 31, and 32 are all tied to +5v on this donor board, which corresponds to NC, PGM, and VCC on my chip. Good: I won't have to jumper NC to Vcc, but will it cause a problem to have PGM connected to +5v? Also, the second /CE on the PCB will be connected to OE on this chip and the PCB's A17 will be connected to the chip's Vpp.
Being an unreleased prototype, I don't want to solder directly or bend legs so I thought I'd check and see if this pinout might just work anyway. I'm prepared to use 28-pin sockets, cut a hole, and just jumper VCC if I have to.