[hakfoo]

3.3 seemed to be a common base for a long time, and a lot of people skipped 4.0. The big feature it brought to market was support for >32Mb disc partitions, but at the cost of using enough conventional memory that you needed bootdiscs to turn off "superfluous" stuff like mouse drivers to play some games.

5.0 brought the ability to load a bunch of stuff high, so you could finally have your cake and eat it too.

[pjmlp]

During those days, I used to carry around a 1.44 floppy with MS-DOS 3.3, Turbo Pascal and a few other utilities.