MCUmall EPROM BIOS Chip Burner Forum
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oahu99

USA
1 Posts

Posted - 03/22/2016 :  10:24:17  Show Profile  Reply with Quote
Hello, I am working on testing a few memory chips I pulled from an NES game. The two chips were a 32K and a 128K EPROM. I have the CRC32 for the chips so I know what should be on them. I was able to read the 32K chip because its pinout is identical to a 27c256, and the checksum matched. For the 128K eprom, its pin out is not identical to another existing eprom. I think I may need to create a custom device for it to read correctly. Can anybody give me a hand?

Here's the pinout of the mask rom, it's 128Kbytes
---_---
PRG A15 - |01 28| - +5V
PRG A12 - |02 27| - PRG A14
PRG A7 - |03 26| - PRG A13
PRG A6 - |04 25| - PRG A8
PRG A5 - |05 24| - PRG A9
PRG A4 - |06 23| - PRG A11
PRG A3 - |07 22| - PRG A16
PRG A2 - |08 21| - PRG A10
PRG A1 - |09 20| - PRG /CE
PRG A0 - |10 19| - PRG D7
PRG D0 - |11 18| - PRG D6
PRG D1 - |12 17| - PRG D5
PRG D2 - |13 16| - PRG D4
GND - |14 15| - PRG D3
-------
Reply #1

ZLM

2923 Posts

Posted - 03/22/2016 :  11:52:01  Show Profile  Reply with Quote
It seems only A16 is difference. Your should be able to red the chip second half content twice.

You can disconnect the chip pin A16 and connect that pin to the pin just above the A15 of programmer IZF.

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