An incomplete, buggy and suboptimal GameBoy emulator written in Go purely for fun. It displays pixels, makes noises and can export GIFs. Hopefully it can prove remotely informative!
All code available here is raw, broken, doesn't follow any specific kind of workflow and isn't guaranteed to work in any way or form.
It might contain blatant errors, awkward workarounds and the occasional profanity in comments or commit messages. Golang at least guarantees that the formatting is somewhat consistent.
Those are the main reasons why this code used to be self-hosted for so long.
The easiest way to run Goholint for now is probably to use go get.
go get github.com/lazy-stripes/goholint
$GOPATH/bin/goholint -help
The emulator ships without any kind of ROM for hopefully obvious reasons. If
you want a scrolling logo, the emulator needs a boot ROM it will attempt to
read from bin/boot/dmg_rom.bin or whatever path you specify with -boot.
(Note: if you don't want to hunt down the GameBoy's boot ROM, simply start the
emulator with the ‑fastboot parameter to bypass it entirely. It doesn't work
as well as using the boot ROM yet, alas.)
With that taken care of, go run main.go ‑rom <path> should be enough to see
an SDL window potentially displaying some interesting things, or more likely a
blank screen, if it doesn't crash first.
(As of 2020, Tetris and Dr. Mario are kind of playable!)
The following controls are set by default:
| Action | Key |
|---|---|
| A Button | S |
| B Button | D |
| Select Button | Backspace |
| Start Button | Return |
| Joypad Up | Arrow Up |
| Joypad Down | Arrow Down |
| Joypad Left | Arrow Left |
| Joypad Right | Arrow Right |
| Screenshot | F12 |
(It's sort of okay on QWERTY and AZERTY keyboards alike but does make Metroid II awkward to play.)
You can customize controls using a configuration file, either via the -config
flag or by creating a .goholint.ini file in your home folder.
See options/config.ini for details.
UI font is Press Start 2P Font by codeman38
The present project only exists thanks to Tomek Rękawek and his fascinating blog article about how relatively easy it was to start implementing a GB emulator. His own emulator, coffee-gb, was a great help and inspiration in the making of this.
I otherwise officially blame @dmuth for retweeting the aforementioned blog post.
Also @balinares for motivating me to make this public. Love you guys! ♥