Usage of the Super CPU and games that supported it

[Frozone212]

Is there any way to program the Super CPU addon for the c64 and what games made use of it?

[carlsson]

1. Yes, at least in assembler as it uses a 65816 CPU. I didn't look it up in detail.

2. Here is a list of known games: http://supercpu.cbm8bit.com/games.php

 

Edit: Actually the entire site is dedicated to the SuperCPU so you'll find more information there.

http://supercpu.cbm8bit.com/index.htm

Edited January 22, 2022 by carlsson

[bjonte]

Game support for SuperCPU isn’t common. Most won’t work in a way that makes sense if they work at all. The reason is that they haven’t been written in a way that takes varying CPU speed into account.

Making games for the SuperCPU falls into two categories - making for the SuperCPU or making it work on the SuperCPU. Making it work is a lot easier. You just need to make sure to disable the turbo speed whenever you need the speed of the CPU to be deterministic and that no illegal opcodes are used. Any cycle exact code, like turbo loading from disk or raster effects can be affected. You also need to make sure it is timed against something deterministic, like the screen update or timers.

Making it specifically for the SuperCPU is a bit more work since you need to program it in 65816 assembler to get most out of it (but you don’t need to). Using the 65816 unlocks the use of extra RAM, if you have access to it. The downside is that this processor has a significant pitfall with its 8 or 16 bit mode that will likely cause you a lot of surprising crashes on the road ahead. I’ll also warn you that if you make a game for the SuperCPU you will undoubtly be criticized with arguments like ”this can be done without SuperCPU”.

Making productivity applications is a lot easier. Everything will just be faster and depending on the model you can make small adjustments to gain a lot of speed (telling it where the VIC chip is looking basically). You don’t need to program the 65816 for the super speed.