2.4 Megabyte Floppies

[joseph c lang]

On Friday 08 September 2006 17:53, you wrote:
> On 9/8/2006 at 5:23 PM Patrick Finnegan wrote:
> >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).
>
> A Catweasel histogram of a track of one of these might shine a little light
> on the recording technique used.  Could be CGR or even a flavor of RLL.
>
> But isn't this drive on the 3174 read-only?
>
> Cheers,
> Chuck

Actually it's not read only. It's just used that way most of the time.

I'm using a couple of drives from a cluster controller. I had to figure out
how the 2.4 meg worked... 

They have a two speed spindle 360/180 rpm and use 500kbit mfm just like 
8" dd disks. 
2.4 meg. only works on "microcode" disks though. And they are pretty scarce.

joe lang