MS-DOS 2.11

Fred Cisin cisin at
Thu Jul 30 15:44:54 CDT 2020

> <snip>
>> BTW, A "1.2MB" drive is fully capable of reading/writing the Otrona disks
> <snip>

On Thu, 30 Jul 2020, Robert Feldman via cctalk wrote:
> I have legal copies of several format translation programs, including 
> Media Master and Convert, but they are 16-bit MS-DOS programs and will 
> not run on my Windows 10 Pro computer. I have Windows XP and MS-DOS 6.22 
> running in VMs under VirtualBox, but I cannot get the VMs to recognize 
> my 1.2 MB drive (a Mitsumi D509V3) as a 1.2 MB drive -- the VMs seem to 
> think it is a 3.5" 1.44MB drive, so the drive is not readable in the VM 
> and the translation programs run but don't work. Also, the BIOS does not 
> have support for any 5.25" floppy capacity other than 1.2MB. If I try to 
> read 360KB floppies, I get a failure message with the comment that the 
> floppies are most likely unformatted.

That is tragic.
Hence the need for the word "MOST".
In addition to suitable software, the hardware needs to support a 300K 
bits per second data transfer rate with a "1.2M" 360RPM drive,  OR a 250K 
data transfer rate with a 300RPM drive.

I'm sad that they would build a machine that can't even read traditional 
distribution floppies (360K, but also 160K/180K/320K).

If we were sufficiently insane, it would seem to be possible to use its 
500K data transfer rate with a drive modified to run at 600 RPM. 
(similarly to some early Sony 3.5" drives)

> It looks like I will have to break down and get a real 386 or 486 PC so 
> I can use a real 360KB floppy drive and run MS-DOS directly.

Sadly, yes.
If the machine will at least handle "720K" 3.5" (which is a 250K data 
transfer rate), then it could still be used, IFF the "1.2M" is 
300RPM/360RPM switchable.

But, one unit of classic hardware, or slightly less brain-dead "modern", 
or even a flux transition reader, would solve it.  And, permit access to 
many hundreds of other disk formats.

Grumpy Ol' Fred     		cisin at

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