jsGB: A Gameboy emulator in JavaScript

jsGB is an interpretive emulator of the Gameboy, designed to be run from within a web browser. Yes, it's written in JavaScript.

Current progress

ROM loading

At present, the test run can load a ROM given a known path to the server. This is done by fancy AJAX, and thus it should be possible to display a dialog of available ROM files, or allow for upload of ROM files. That's for later, of course.

CPU

All instructions in place; all the common ones are tested working. One known issue is that half-carry isn't calculated.

GPU

Background: Palette in place, Y-scroll and X-scroll tested working. The BIOS "Nintendo" logo appears. Windows: missing.

Sound

I've no idea how this can be done from JavaScript; this is unlikely to be implemented.

Test Results

The emulator currently works in the following browsers:

• Firefox 3.6 (slightly slow, as to be expected)
• Opera 10 (quick)

Screenshots

Tetris

Acknowledgements

The following people have helped contribute to this project:

• Pan/ATX, nocash and others: Pandocs specification document
• Sean Young (CS dept, Vrije University): Z80 opcode map and specification document
• Mostek: Z80 timing specs
• Pat Fagan: Diff sheet between Z80 and Gameboy Z80 CPUs
• Kevin Mantey (Physics dept, UIUC): First microscopic dump of the Gameboy BIOS
• Arvidsson/Eklund/Murphy: ExCanvas for IE
• Andy Na: XHR binary file reader

Imran Nazar <tf@imrannazar.com>, May 2009 - Aug 2010