On Tuesday, October 18, 2011 12:33:32 PM UTC-4, Leon wrote:

snip

Really, I thought that IBM was only coming with the MS version.

You could buy PC-DOS or MS-DOS. PC-DOS came in a gray binder that said "IBM" on the cover, MS-DOS came in a green binder that said "Microsoft" on the cover. The only functional difference was that the one that said "Microsoft" on the cover included a BASIC interpreter that would run on a machine without ROM-BASIC while the one in the IBM version required ROM-BASIC.

IBM never bundled the green binders with their own machines, but you could buy the grey binder version without a machine.

I do recall buying a different OS back then that was about $25 IIRC.

Which OS? IIRC, PC/DOS was about $50.

I really cannot remember for sure but .... DR DOS may be??? I guessing
here. I did not use it past trying it out.

http://en.wikipedia.org/wiki/DR-DOS