> It's a lot of effort for a couple of dozen pixels.

Sometimes, "because it's possible" is all you need ;-)

But now, more seriously, it'd be fun to try to port it to different 6502-based computers. I've been looking for a good excuse to get myself an Apple III or a BBC Master and this seems like a great one. Not all of them will be able to have preemptive multitasking (interrupts aren't always convenient), but it'd still be fun.

Imagine that - in 2023 we could have software that runs unmodified on more than one 6502-based computer...