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Welcome to the EmulAtar home page. 
EmulAtar is (going to be) an Atari 2600 emulator for Linux. It was made just for the hell of it by me, Phillip Powers. Right now, it is in very early (Alpha? :) stage of development. So don't download this thinking you're gonna be able to play River-Raid! I only get to work on this thing about an hour a night, and it's usually LATE at night when I should be sound asleep! This project was made purely as an educational experience for myself. I have always been interested in the technical aspects of emulation (as opposed to the piracy aspect) and have always been a fan of the Atari2600.  I have had an incredible surge of energy for coding lately, and am anticipating a release rather soon :)


The emulation has been progressing nicely. I have become quite adept at disassembling ROMS and seeing where bugs in the emulator are. There are quite a few games that are "viewable" and "movable" and have great interaction. As to "playable" games, I'm not quite sure. Tetris (demo) seems to work wonderfully. Pacman is great! Defender is great! There are, of course, many others. However, until missile gfx, ball gfx, and collision detection has been implemented I will not dubb _ANY_ game "playable."  Here's more...

Basically, there are three (3) main points to any VCS emulator. (Technically)
These are:

  1. 6502 Emulation. (Main CPU)
  2. 6532 Emulation. (Switches/Timer/Ram)
  3. TIA Emulation. (Gfx/Sound)
Number 1, the 6502 processor, has been pretty well implemented. That's not to say it's 100% complete. Actually 6507 emulation would be more accurate in describing what is emulated. My 6502 core does not contain any support for interrupts, therefore not a true 6502. There are some bugs in it, I know. For example, BCD subtraction isn't working correctly. I'm not 100% sure on BCD addition, either. I think that there could almost be a number 4 up there: Memory Emulation. However, I think this ties in too much with the 6502 to give it its own category.

Number 2, the 6532, is pretty much completely emulated. The timer has been implemented and I am pretty sure it works correctly. It seems to on all the Atari demos I have gotten to work thus far. IO ports have been partially emulated. Basically, there is support for player0 joysticks and fire buttons. No support for player1 joystick or paddles have been implemented yet.

Number 3, the TIA, is a nastly little chip! Emulating it is actually proving to be quite a task, since this is where all the action for the Atari occurs. I mean, come on! MANUALLY drawing out the frame for EVERY frame!! Playfield emulation is great. Player graphics are pretty good. Missile and ball graphics are there. There are some issues here, however. IE, Not all games work! :)


Please feel free to send any suggestions, flames, marriage proposals,
improvements, patches, etc. to THE NAKEDMAN.