8 Nov
2001
8 Nov
'01
8:57 a.m.
On Thu, 8 Nov 2001, Fred Cisin (XenoSoft) wrote:
Micropolis was one of the only ones to use a helical
lead screw positioner
for a 5.25" floppy. VERY SLOW. They also made a 100TPI (not 96) drive.
Tandon also made a 100TPI drive.
- don
Starting with the MPI B51, most drives went to a split
band positioner.
In addition to the spiral groove positioner, the SA400 was 35 track,
whereas all others that followed were 40 track.
On Thu, 8 Nov 2001, Richard Erlacher wrote:
That spiral cam was an attempt to reduce price
and mass, I suppose. Like the
stone wheel, I imagine it was better than SOME of the other options available at
the time, in one respect or another.
I don't remember at all (go figure!) what options there were at the time, short
of the lead-screw that was used on 8" drives, for moving the heads. I've got a
few pictures of Siemens mini-drives (5-1/4") that use lead screws, but I don't
remember other vendors using them. Did Shugart make a minifloppy with a lead
screw? The old BASF drives that I've cussed from time to time for their
fragility at the door latch used that spiral cam arrangement. It was
interesting, and, if you worked at it, you could foul it up, since it was
readily accessible. Every other scheme I remember from that period used a
tendon drive, as did the DS 8" drives, other than Siemens'.
What do you remember?
More than I care
to.