Kaypro came with 5.25 IIRC... around the same time frame as the Osborne and the Commodore VIC-20, TI 99/4A, Timex Sinclair 1000, etc.
I don't recall any home PCs that had 8 inch drives as standard or integrated peripherals. Even the big silver expansion box for the TI, was 5.25 inch (lot of summer vacation money spent on that, before discovering the C-64 and switching
). Not to say no one made one or jury rigged it. The last 8 inch disk I used was ~'87, I repaired an old VAX - fun, but kinda a pointless enterprise since it was so freak'n loud, I barely played with the thing after I got it running!
Ironically, given your post, I salvaged the huge (noisy) dot matrix printer that came with it and emulated a plotter for very long printouts. Jury rigged it to what I called Trash-80s - a Radio Shack computer I can't even recall the name of right now (TRS-80 Model 3/4 comes to mind?) and wrote an emulator in assembly for several physics class programs (wave reflection, curve fitting, etc.) I had written. Also recall making an ASCII mandelbrot set 'banner' that was like 40 feet long. (And ASCII ⌧ - hey, I was a teenager!)
Of course, was kidding about the Kaypro.
Though it is possible - old systems lasted a long time, especially without a HD to fail and with well made caps and transformers. Yes, there are (well, were, last I checked) lots of CP/M Z80 and 80xx emulators... as long as nothing BIOS specific was used, a lot of stuff should still function.