I saw that someone already mentioned, but only in passing, the DEC Rainbow 100. It was a great machine for its time, with Z80/8088 CPUs allowing it to run both

I saw that someone already mentioned, but only in passing, the DEC Rainbow 100. It was a great machine for its time, with Z80/8088 CPUs allowing it to run both 8 and 16-bit software. But they had a special (even proprietary) floppy disk format. You couldn't format your own floppies. You couldn't even purchase any floppy brand. You had to order from DEC at $5 apiece, and you got a paltry 400K 5.25" floppy that you couldn't even format. This was corrected later but then the damage was done and the Rainbow never took off. https://en.wikipedia.org/wiki/Rainbow_100 https://en.wikipedia.org/wiki/Rainbow_100