A GameBoy Advance emulator written in TypeScript that runs in the browser.
ts-gba uses tsc and esbuild to compile and bundle the TypeScript source into a single JavaScript file. This file is referenced by the index.html file to call emulator functions from within the HTML UI.
> git clone git@github.com:SkylerRankin/ts-gba.git
> cd ts-gba
> npm install
> npm test
> npm run build_web
> ls dist
dist
├── index.html
└── tsgba.js
To run the emulator, open or host file at ts-gba/dist/index.html. From there, upload a ROM and optionally a BIOS file and/or save file. Press Start to begin the game, and press Pause under the CPU tab to use debugging tools.
The project currently implements enough of the GBA features to play Gen 3 Pokemon games (see Emerald and Fire Red in screenshots). Game saves can be downloaded/uploaded as files or saved/loaded from local storage.
Next Steps:
- Improve framerate
- Support GPIO devices (RTC is used for clock stuff in Pokemon, but not necessary to run game)
- Support other cartridge save types (currently only 128KB flash memory)
- Implement audio
- Graphical bugs (e.g. occasional sprite priority issues)
This project includes a few basic debugging tools, listed below.
- CPU register, CPSR, and SPSR viewer
- Instruction disassembly with steps and breakpoints
- Byte level memory viewer
- Status of all the interrupt configurations
- Display control status
- View of tiles in VRAM, divided into character-blocks, with palette and bit-depth controls
- Background and object palette color viewer
Examples of debugger running in game:
The following resources were essential in making this project possible.
- GBATEK: The comprehensive GBA technical reference. Pretty much all concepts and hardware details needed to understand the GBA are documented here.
- The official ARM Architecture Reference Manual: Contains everything needed to implement the ARMv4T instruction set.
- Tonc: A detailed series covering the most important aspects of GBA game programming. The demos provided were essential in being able to test GBA features in small, isolated pieces of code.
- No$ GBA: An excellent GBA emulator that provides lots of debugging UI. The ability to step through instructions in No$ and compare the state to my emulator was critical in debugging and saved hours of time.