Gameboy Development Forum

However, I am searching for a BIOS programmer to analyze the data of the Game Boy CPU chip.

AntonioND wrote:

Using a generic programmer won't work.

The data bus of the chip is only enabled when accessing external addresses, not when reading the boot ROM.

The only way to dump the ROM that is easy enough for one person is to glitch the clock of the CPU, hope that the CPU lands in some code in your cartridge that saves the ROM to SRAM or something, and then read it from the computer.

Seriously, you are thinking about this in a completely wrong way. The boot ROM is protected. Nintendo doesn't want you to read it. There is no easy way to read it. You need to trick the CPU so that you can read it.

Have you actually read https://www.its.caltech.edu/~costis/sgb_hack/ and understood what it says? If not, give up. The trick is to glitch the CPU so that it skips the instruction that disables the boot ROM, or so that it jumps to some random address and hopefully reaches your code by pure chance.

I understood what I have read so far, but I think that the simplest method of dumping the Game Boy boot ROM is using one wire to hit the Game Boy CPU clock pin. Using the GB-BRK stuff with a bunch of the wires may take a long time to dump the Game Boy boot ROM.