Atari 2600 Game Development

gjb6676 writes "An article over at ExtremeTech is covering recent game development projects on the Atari 2600. The amount of cartridge space they have to work with is a sobering thought: 'A two-word file in Word 2002, for example, requires 20 Kbytes. "That's 20 Kbytes, five times the amount of (ROM) space developers had to work with in the 2600.'"

Comments

The Good Old Days

[FormerComposer]

Working on the Tandy Color Computer was similar. I programmed Super BustOut for the initial release of the machine. 4K Rom, 1K Ram (1/2 of which was the screen.) You had to squeeze every byte out of the 6809's instruction set (one of the greatest processor designs ever!) But we ended up with a great game ... like Breakout but with
* 2D paddle motion
* horizontal or vertical brick orientation
* gravity in some modes
* "English" on the paddle/ball interactions
* single or dual player in competitive or cooperative simultaneous play
* sound effects (CPU generated)
* etc. etc.

Just before release, with 9 free bytes left, a bug was found. The initial fix would break the ROM barrier by 13 bytes. Yet another pass through the code doing the 4th or 5th optimization -- finally got it in and ended up with 11 free bytes.

Amazing what is possible in ASM but, boy, it was many 20 hour days!

So I understand those 'smallest executable' contests, but how much functionality does the executable really have? Or how much of the Word document is really information?

Ah, memories

[mr_death]

I was the co-developer on the Atari 2600 versions of Jungle Hunt and Pole Position.

Yes, there were two players (8 pixel sprites) and two missiles (1, 2, 4, or 8 pixels wide, if memory serves.) And the "easy" way to set up a display line was to write the bitmap and position of the players and missiles during vblank.

However, there was an underhanded way of getting more than two players on a line, if they were separated by enough space (~12 pixels, if memory serves.) While the line is drawn, you keep track of where the "currently drawn pixel" is. When that location is just past the end of a player, you reposition the player to ~12 pixels ahead of the current position, and rewrite the bitmap. We (General Computer Company, a captive developer for Atari) could get up to 6 players on a line, if they were separated by enough distance.

Yes, I am dating myself ... but oh, what memories.