[nitro2k01] got his hands on a Game Fighter, a clone of the original Game Boy. While there’s a ton of information about the boot ROM and operation of the original Game Boy, not much is known about these clones. [nitro2k01] wanted to learn more, so he used a clock-glitching technique to dump the device’s ROM and made some interesting discoveries about its copyright protection and boot process along the way.
Reading the contents of the Game Boy ROM is a bit challenging. The ROM is readable while booting, but afterwards the address space of the ROM is remapped for interrupt vectors and other uses. There are a couple of methods to get around this, but the simplest method involves glitching the crystal by grounding one of its leads. This causes the CPU to jump to random locations in memory. Eventually the CPU will jump to a location where the boot ROM is accessible (if you’re lucky!).
Although [nitro2k01]’s clone can run the same games as the Game Boy, it has a different boot ROM and also has some significant hardware differences. [nitro2k01] managed to use a modified version of the crystal-grounding technique to glitch his clock and dump the clone’s boot ROM. He found that the clone uses an unusual variation on the Game Boy’s copyright-checking technique, along with some other oddities. [nitro2k01] also posted a disassembly of the boot ROM, which he explains in detail.
Thanks for the tip, [Ove].
Welcome to the DCEmu Homebrew and Gaming Network. This Network of sites is owned and ran by fans of all games consoles, we post news on all the consoles we cover about hardware aspects, gaming and Homebrew. Homebrew and Emulation are software thats made using free and legal tools to play on games consoles. This Network is the only worldwide network of sites where coders can upload and post comments they deserve for all their hardwork. We have a Network that currently supports PSVita, WiiU, Nintendo Wii, Xbox360, PS3, PS2,PS1, Snes, N64, Gameboy, Nes, Xbox, Gamecube, Nintendo DS, PSP, GBA, Dreamcast, Sega Saturn,3DS, DSi, Switch, PS4, Pandora, xboxone, GP2X, iPhone, Windows Phone, iPad, Android and also Mobile Phone Emulation. When new consoles appear we will expand to cover those consoles. We also cover Theme Park News and news and reviews of Beer, cider, lager, wines and spirits.
news of their own releases and get the credit and
Please help DCEmu become stronger by posting on the forums every day and make our community larger.