I'd be impressed with someone using one of those to make memes, honestly.
You should save as jpg instead. It must take forever to write those pngs to an IMSAI.
The C64 kills it on graphics and sound, but probably not disk access. The C64 used the main CPU to control the drive instead of a separate controller.
The SID chip is still impressive. I wish computers still came with some kind of multi-channel PSG.
Amiga derivatives are still being produced, but the state of things is bad enough that you end up paying $1000 for an underpowered FPGA simulation.