gameboy homebrew cartridge writer

Last update: Thu Jun 5 22:25:41 2025

So I made a semi-failed Gameboy homebrew cartridge (the modest) that doesn't work as a GB cartridge but works fine as an EEPROM writer. But you need a program on your computer to talk to the board, and send/receive data. This present program.

Presentation

Principle

Just a simple python Serial client that talks at 57.6kbps to the Gameboy homebrew cartridge microcontroller. Wrote it to work with 32kB ROM only, so if you wnat to make it bigger, edit the code. It can download a 32kB ROM in like 20 sec, but writing is longer at about 5 minutes for 32kB.
My suggestion is to write, then download what you wrote and compare to be safe.

Points of interrest

Not much, a simple serial client. I like the progression indicator with the print("\r") trick and the remaining time calculation. Nothing much otherwise.

Implementation

Source code

Runs on Python 3, you'll need to pip3 install pyserial for it to work.

Script is on my GitHub: https://github.com/AlanFromJapan/alanarduinotools/tree/master/Python/GBCartridgeClient
EEPROM programmer at work

All content on this site is shared under the MIT licence (do what u want, don't sue me, hat tip appreciated)
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