Apsd has just released a Chip8 Emulator.  He started this emulator a couple months ago, and got busy with infrared releases, forgetting about this emulator.  Well, he has finally released it, and here is what he had to say:

Almost two months ago, before I got busy with the infrared stuff, I wanted to write a first emulator and got advice from ector to start with Chip8 interpreter... About three days after I wrote a working version on my computer, I ported it to the PSP and ever since it has been sitting here...

I've finally gathered up this post to release this beta version of the emulator. I call it beta for three reasons, the first is that there is a bug I need to weed out that causes it to improperly play tetris, the second is that the key arrangement is currently not optimized, the third is that the sound code for the single "beep" (which can be varied in length throughout the games) isn't implemented. (the Chip8 interpreter has 16 keys, so all convenient keys on the PSP are used (Circle, Triangle, Cross, Square, Up, Down, Left, Right, Analog stick up, down, left, right, and a few others... two keys are disabled in this version).

I've packaged the interpreter with just about every Chip8 game (they're public domain) I could find.

I'll release the source once I clean it up.

Expect SCHIP8 (SuperChip8- a few new instructions, extended screen) support in about two releases- these games are slightly more interesting.

Read the readme for more information, and check wikipedia if you want to learn more about CHIP-8.

Don't expect these "games" to be breathtaking. [S]CHIP-8 was a very simple interpreter.