jsSMS JavaScript Sega Master System & Game Gear dynamic recompiling emulator
To get some technical insights, watch the video of the talk about JSSMS I gave at Reject.js 2013.
There are also the slides in HTML.
Controllers
| Button | Player 1 | Player 2 |
|---|---|---|
| Left | Left | Num-4 |
| Right | Right | Num-6 |
| Up | Up | Num-8 |
| Down | Down | Num-2 |
| Fire 1 | X | Num-7 |
| Fire 2 | Z | Num-9 |
| Start | Enter | Num-1 |