MS-DOS 2.11

Fred Cisin cisin at
Wed Jul 29 14:35:36 CDT 2020

On Wed, 29 Jul 2020, Robert Feldman via cctalk wrote:
> I already have the Otrona MS-DOS 2.11 disks from Don Maslin's archive, 
> but (as I forgot to mention), I do not have a modern computer with a 
> 360KB floppy drive. I have an old Dell Precision T3400, but its BIOS 
> will only allow 1.2MB 5.25 floppies.
> The version from the Maslin Archive and both my original Otrona MS-DOS 
> 2.11d disks (from 1983) and the MS-DOS-2.11 2.11e disks that I 
> downloaded from FAUG after Otrona went out of business do not include 
> Assign or Subst. However, the 2.11e disk includes support for a hard 
> drive, so I believe that it can handle a C: drive.
> I received a copy of Assign from MS-DOS 2.1 from another list member, so 
> I have asked him if he can copy it to a floppy that I can send him.
> Bob

MS-DOS 2.11 was one of the ones HEAVILY customized by OEMs (likewise 
2.11 sometimes had significant alterations, such as new drive types 
(such as OEMs that used 3.5" drives; PC-DOS didn't support 3.5" until 
PC-DOS 3.20), different videos, etc.  Accordingly, SEVERAL programs, such 
as MODE.COM, FORMAT.COM were different from one OEM to another. 
ASSIGN.COM might not be the same in some other OEM's 2.11.

BTW, A "1.2MB" drive is fully capable of reading/writing the Otrona disks 
Otrona CP/M had 10 sectors per track.  If I recall correctly (unrefreshed 
dynamic wetware), the sectors were numbered 0 through 9.
They had both 40 track per side and 80 track per side 400K/800K formats.
Including an 80 track per side low density MS-DOS.
The usual caveats about [re]writing "360K" in a "1.2M" drive apply.
Start with a bulk erased disk.

Otrona achieved news when IBM objected to their commercial.
Otrona showed a Charlie Chaplin look-alike trying to carry a PC down 
steps.  IBM asserted that THEY owned Charlie Chaplin.  So, the ad 
only aired half a dozen times.
Discussed in July 1983 PC Magazine p331.
Does anybody have a copy of that ad?

Grumpy Ol' Fred     		cisin at

More information about the cctalk mailing list