-Several MSX-DOS versions
-Several MS-DOS Versions (3.0, 4.01, 5.0, 6.0, 6.2, 6.22)
-Other DOS versions (PC-DOS, DRDOS, FreeDOS
)
-MacOS (don't remember the version, long time ago at uni)
-GEM for PC
-Almost all Windows Versions, starting from 3.0, except Vista. Me was only tested very briefly
)
-Several Novell Netware Versions (4.11, 5.1, 6, 6.5)
-Unix (used it a lot when studying at the University)
-Linux Distros (minix, suse, Fedora, Knoppix, Damn small Linux)