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From: 3ksnn64@cadlab.ecn.purdue.edu (Joe Cychosz)
Newsgroups: comp.sys.cdc
Subject: Re: Wanted.. any info on 26" disk drive platter
Keywords: ancient,relic
Message-ID: <1990Sep11.034940.16212@ecn.purdue.edu>
Date: 11 Sep 90 03:49:40 GMT
References: <6536@tekgen.BV.TEK.COM>
Sender: news@ecn.purdue.edu (USENET news)
Organization: Purdue University Engineering Computer Network
Lines: 56

In article <6536@tekgen.BV.TEK.COM> ralphc@tekcae.CAX.TEK.COM (Ralph Carpenter) writes:
>
>An interesting reminder of my youth hangs on the wall of my
>cubicle:  a 26" platter from a CDC 6600 disk drive that was
>decommissoned about 1973.  I think the unit was a Bryan(t).  As I
>remember, the heads were hydraulically driven.  The story was
>that one job would periodically show up that put the mini-van
>sized unit into resonance and, unless the operator rolled that
>job out until some other jobs came along to randomize the head
>movement, the whole unit would hop until it moved off the holes
>in the raised floor.
>

You are right.  It was from a Bryant disk, otherwise known as the
6603 disk.  CDC did make a drive that had even larger platters
approximately 3'-4' in diameter.  The University of Illinios use
to have one on there G20 system.  I remember rolling the platter around
in the hallways of the EE building.  They also made nice coffee tables.
One such table use to be at FermiLab.

Anyway, back to the Bryant:

	Capacity:	56Mbyte
	Weight:		4,300 lbs
	Surfaces:	32 (4*9 - 4)

The unit had 4 quadrants.  The quadrants were organized into a upper
half and a lower half.  Each half used equal and oppsite positioning
to conteract arm movement.

The first unit was delivered to Livermore.

My friend Don Crouse who installed a good many of these drives has quite
a few stories about these drives.  The most notable are:

1.  One drive that was  on its way to France fell out of the loading
    bay of a 707 to the ground.  Upon arivial in France, the drive
    worked even though it was shaped more like a parrallelogram instead
    of a box.  The heads were wrapped and locked in there retracted
    positions and survived the drop.

2.  While installing a 6600 system in Mexico, one of the Bryants fell
    through the floor.

The Bryant was the last of the big disk technology.  Shortly after it
14" technology arived on the scene, which lasted up until a few years
ago (yes I know there are some 14" drives still in production, but
the majority are much smaller now).

If you get some of that magnetic partical material that they use to
evaluate magnetic tape media and spray it on a portion of your disk
you should be able to read the bits.

Joe

Bytes/lb is left as an exercise of the reader.