Read a 32K Game Boy cartridge

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arpruss
Posts: 83
Joined: Sat Dec 21, 2019 10:06 pm

Read a 32K Game Boy cartridge

Post by arpruss »

I found a Tetris Game Boy cartridge PCB on the street. After some false starts (either due to a faulty GPIO or a faulty breadboard connection), it turns out to be super-easy to read a 32K cart with a black or blue pill. Cartridge pinout is here: https://dhole.github.io/post/gameboy_cartridge_emu_1/

For this cart, CLK, WR, RESET and AUDIO were not connected to anything, so I ignored them. Since it's only 32K, you can ground A15. Since you're not writing data or switching banks, you can ground RD. Ground GND. Then connect D0-D7 to some pins on the pill, ideally 5V-tolerant ones (so you can run at 5V if necessary). Connect VCC to 3.3V, but if that fails, go for 5V (3.3V worked fro me). Here is a little sketch that reads the data. I then just copied the data from the Arduino serial monitor into the input of a Python script that turned it into binary.

I didn't have any a cartridge connector, so I just stuffed jumpers into plated through holes on the PCB, and used test clips for two lines (VCC and RD) that didn't have through holes. It's a mess, but the checksum checks out and the game works in an emulator. This was quick and dirty. (If one really wanted to do a nice job, one could use the USB Composite library to emulate a small flash drive and make the cartridge appear ike a file on it.)

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ag123
Posts: 1655
Joined: Thu Dec 19, 2019 5:30 am
Answers: 24

Re: Read a 32K Game Boy cartridge

Post by ag123 »

+1 nice, but i think there are some connectors which may fit the row of pins, i'd guess the old pc ISA type connector may help there
there are probably some better solutions
arpruss
Posts: 83
Joined: Sat Dec 21, 2019 10:06 pm

Re: Read a 32K Game Boy cartridge

Post by arpruss »

But I had no such connectors at home that I could find, unless I were to desolder them from an old PC which is still in occasional use. :-)
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