If you’ve spent some time playing games on the Atari 2600, there’s a very good chance you’ve gone through a few rounds of combat. The two-player battle game not only comes with the console but is actually one of the more technically impressive titles for the system, offering nearly 30 variations on the core head-to-head gameplay formula. head.
But unfortunately, none of the modes include single player. That is, until [Nick Bild] is in the case. While some concessions had to be made, he succeeded where the original developers failed, and added a computer-controlled enemy to combat. What’s more, the game still runs on stock 2600 hardware – no emulator tricks needed. True enthusiasts may be surprised by the snippets of source code he provides, but the rest of us can just watch the video below the break and be amazed at the success.
If you have never worked with such a limited system, this may not seem like a big deal. but [Nick] good job of explaining not only what he did, but why it was so hard to pull off in the first place. For example, the console does not have a video buffer, so everything must be done during VBLANK where the game does not need to draw the screen. Unfortunately that didn’t give him enough free cycles, so he had to split his code to run on three frames instead of just one. That means the game’s original logic is now only running at 27 frames out of 30 per second, but he says you can’t really tell in practice.
As such, some cuts must be made. He had to remove the strangely complex machine sounds to free up some resources, and had to bump the 2 KB cartridge up to 4 KB to hold the new code and data. The 2600 can handle larger cartridges by switching the bank though, so this shouldn’t be a problem.
Because of its age and limited capabilities compared to more modern consoles, you might think that the Atari 2600 is little more than a footnote in gaming history. But there is a devoted group of people who enjoy squeezing everything they can out of 45-year-old system hardware that lead to labors of love like this.