Doom (Commodore SuperCPU)


Title screen in 16-color mode.

Doom for the Commodore SuperCPU is a direct port of the Linux Doom source code to the Commodore 64 and Commodore 128 computer systems with the SuperCPU upgrade, which consists of a 65c816 clocked at 20 MHz with an accompanying 16 MB RAM upgrade. It was developed by Commodore hacker AmiDog as a test application for his MIPS Recompiler, a program which allows dynamic binary translation of MIPS programs to the 65c816.


The game is a straight port with virtually no optimization aside from translation of several core routines for fixed point math, column, and span drawing into assembly code. Due to the lack of compromises made for the primitive target architecture (the CPU is a faster cousin of the Super Nintendo's Ricoh 5A22 processor, for reference), the game runs at a virtually unplayable single-digit frame rate. Since the project's purpose was primarily to allow tuning the MIPS Recompiler, the author did not aim to improve this any further.

Support is provided for two different video modes, including 16 color mode. There is no audio support.

The shareware IWAD is baked into the RAM Expansion Unit (REU) used to load the game.


External links[edit]

Source code genealogy
Based on
Linux Doom v1.10
Doom for Commodore SuperCPU Closed source