Last version of DOS to support Jr?

[OldComputerGuy]

So what is the last version of DOS to run on a Jr? I had heard it was 4.01, but not entirely sure about that.

[Brutman]

IBM DOS 3.3 is the last version of DOS officially supported on the PCjr. 4.01 might work, but it had a bad enough reputation where I don't even want to bother with it. DOS 5.02 and DOS 6 can be patched to work on a 256K machine - see previous forum postings for the procedure.

[Percussionista]

I was able to run DOS 5 on mine, with 640k no problem, though no real reason to do so

[Brutman]

A big reason to run DOS 5 is large partition support ... with DOS 5 you can go over 32MB per partition. That's useful for those of us using hard drives on the Jr.

[Percussionista]

Aha! Well, I never got beyond floppies. I forget that many folks turned their Jr's into "real" computers. Pretty cool!