[TUHS] Disk data layout (was: /dev/drum)

[clemc@ccc.com (Clem Cole)]

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On Fri, Apr 27, 2018 at 2:16 PM, Paul Winalski <paul.winalski at gmail.com>
wrote:

> On 4/27/18, Dave Horsfall <dave at horsfall.org> wrote:
> > On Wed, 25 Apr 2018, Paul Winalski wrote:
> >
> >> Bin number was zero except on the IBM 2321 data cell drive.  CKD drives
> >> supported a variable number of records on each track, hence the term
> >> "record" rather than "sector".
> >
> > Would that have been the infamous chicken-plucker?[*]  Wherein if things
> > went OK, then they were OK, but if things went wrong...
>
> That's the one.  I'd always heard "noodle picker", though.  From the
> outside it looked like a drum in the shape of a multi-sided polygon.
> Each bin held a number of wide pieces of multitrack magnetic tape.  To
> seek to your data, the drum rotated under a head that pulled the
> appropriate tape out of the bin and wrapped it on rotating drum.  From
> there reading and writing was much like any other drum device.  It's
> as if someone asked Rube Goldberg to design a disk drive.

​Accept that it will like tape in the head contacted the media.

Question for Debbie S --- my memory is you folks had one up the hill at
LBL.  I think that's where I saw it in action.​


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