Tanenbaum has said, "MINIX 1 and MINIX 3 are related in the same way as Windows 3.1 and Windows XP are: same first name"
Minix 1.5 came out for 68k Atari, Apple, Amiga as well as SPARC and x86. Minix 2 was only x86, SPARC and someone else wrote Minix 2 for VMD. Minix 2 supported X Windows, Minix 1 didn't.
The two installation floppies ROOT.MNX and USR.MNX, can be combined on a 1.2 Mb or 1.44 Mb diskette. MINIX.MNX is about 52 MB.
I remember the first time I met someone installing linux. It was Yggdrasill ('96?) and it was on something like 12 floppies. I thought that ridiculous. I waited until Debian 2.0 on CD, which was the very first bootable linux CD.