Doom64

The middle game of the id trilogy for the Commodore 64.

I had already written Doom for the VIC-20 a long time ago, which used a sector based approach with off axis walls, but it had no floor or ceiling heights so it looked a lot more like Wolfenstein to the untrained eye.

So I thought I could spend my cycles on height changes instead of off axis walls. I thought I'd also add light changes, which meant updating a text screen with dither patterns. A 40x25 screen isn't very high res, so texture mapping would look appalling, so I dropped that, which also gives me a bit more memory for lookup tables, mip maps for enemies, music, and so on.

Maps are hand edited on a grid, adjusting light levels and heights using an instant preview window.

Weapons are all sprite based, taking the shareware sprites and scaling, tweaking, and palettizing them.

Sounds are taken from the original PC speaker effects and decimating them. I did this for the VIC port, and it works the same here.