Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!swrinde!mips!ultra!shj
From: shj@ultra.com (Steve Jay)
Newsgroups: comp.sys.cdc
Subject: Re: Wanted.. any info on 26" disk drive platter
Keywords: ancient,relic
Message-ID: <1990Sep11.211524.2956@ultra.com>
Date: 11 Sep 90 21:15:24 GMT
References: <6536@tekgen.BV.TEK.COM> <1990Sep11.034940.16212@ecn.purdue.edu>
Organization: Ultra Network Technologies
Lines: 42

In <1990Sep11.034940.16212@ecn.purdue.edu> 3ksnn64@cadlab.ecn.purdue.edu (Joe Cychosz) writes:

>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.

I think this is confusing the 6603 with the slightly later 6638.  The 6603
had just one positioner which moved all the heads in the same direction
at the same time.  I seem to remember the term "quadrants" associated
with the 6638.  The rest of the info on the 6603 matches my recollection.

The 6603's claim to fame was its very fast (by 1966 standards) transfer
rate: 1.4 Million 12 bit words a second (I think).  It did this by
reading/writing 12 heads in parallel.  Average access time: ~200
milliseconds, average latency: 32 milliseconds (900 RPM), so you had
to wait a while before you saw the high transfer rate.

To this day, every time I write a line of code which will cause a disk
access, I can hear the CLUNK, CLUNK of the 6603 as it moved the heads.

>My friend Don Crouse who installed a good many of these drives has quite
>a few stories about these drives.

Don would come to our site (University of Arizona), and work on his
Super-P diagnostic system while the local engineers took the disk apart.

Where is Don these days?  I haven't seen him in about 20 years.

One of my favorite 6603 stories is the time the engineers left a hydraulic
hose loose while they went to lunch, and came back to find the entire
contents of the hydraulic system (5 or 10 gallons) dumped under our false
floor.  The folks in the offices in the basement wondered about the
yellow stuff leaking onto their desks.  We just missed emulsifying the
entire building when the expanding puddle of fluid stopped short of a
very large air conditioning duct.

Ah, they don't make 'em like they used to.

Steve Jay
shj@ultra.com  ...ames!ultra!shj
Ultra Network Technologies / 101 Dagget Drive / San Jose, CA 95134 / USA
(408) 922-0100 x130	"Home of the 1 Gigabit/Second network"