Worth noting that this is not “software emulation” like how you might run Mini vMac on a modern computer. It was all accomplished with an old retail app called Amx, “the Macintosh emulator for your Amiga.” The hacker explains: Instead, it’s a weird Frankenstein project, in which a vintage Mac’s ROM chips have been connected to an Amiga’s Motorola 68000 processor, which was the same CPU in the Macs back then. So what we’re looking at here isn’t really emulation. Nor could you see a vintage Mac emulate a vintage PC at full speed: it just doesn’t have the bandwidth to “pretend” to be another system.
You could never, say, use an Xbox One to emulate a Wii U at full speed. At the same time, though, this means you can only emulate systems older than current hardware.