2.4 Megabyte Floppies

[Patrick Finnegan]

On Friday 08 September 2006 13:42, Chuck Guzis wrote:
> On 9/8/2006 at 10:01 AM Mr Ian Primus wrote:
> >I've seen them used in IBM terminal controllers as
> >microcode floppies. The drives for said terminal
> >controllers are easy to find - I have many. Disks are
> >scarcer. I don't know if the IBM 2.4 meg disk is the
> >same as the ones used by the Kaypro. I also don't know
> >much about how the format works.
>
> I think we're talking about two different technologies here.  IBM
> used a drive made by YE data that, while 80 cylinder, packed the data
> much more densely on each track.  The Drivetec variety used dual
> positioners in connection with a servo track to get 160 cylinders (at
> 600 RPM).
>
> In either case, floppies for them are pretty rare.
>
> However, I wonder what would happen if one formatted the IBM variety
> using a 3.5' 2.88MB-capable PC controller.

FWIW, I tried hooking one of these up to a catweasel 3 in a PC, and 
while it could read "1.2MB" floppies just fine, I couldn't get Tim 
Mann's catweasel utilities to recognize any MFM or other encoding on 
the data stream that the catweasel card was reading off the 2.4MB disks 
I've got (which are IBM 3174 microcode disks).

Pat
-- 
Purdue University Research Computing --  http://www.itap.purdue.edu/rcac

-- 
Purdue University Research Computing ---  http://www.rcac.purdue.edu/
The Computer Refuge                  ---  http://computer-refuge.org