head-positioners - (was Apple Floppy Drives (was: More Apple Pimpers))
Richard Erlacher wrote:
> Yes, and the Siemens drive with the lead screw looked VERY much like the
> Micopolis drive, IIRC. The split-band actuator (tendon drive) was eventually
> found to be the best tradeoff between cost, precision, reliability, and
> performance.
>
Wasn't the Osborne I floppies Siemens?
Eric
>
> I don't think I ever owned a minifloppy drive with a lead screw, but was quite
> surprised to find it in the Siemens tech manual.
>
> Dick
>
> ----- Original Message -----
> From: "Fred Cisin (XenoSoft)" <cisin_at_xenosoft.com>
> To: <classiccmp_at_classiccmp.org>
> Sent: Thursday, November 08, 2001 10:45 AM
> Subject: Re:head-positioners - (was Apple Floppy Drives (was: More Apple
> Pimpers))
>
> > 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.
> > 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.
> >
> >
Received on Thu Nov 08 2001 - 21:45:55 GMT
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