Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!uc!shamash!rrr
From: rrr@u02.svl.cdc.com (Rich Ragan)
Newsgroups: comp.sys.cdc
Subject: Re: Wanted.. any info on 26" disk drive platter
Keywords: ancient,relic
Message-ID: <25701@shamash.cdc.com>
Date: 12 Sep 90 14:48:05 GMT
References: <6536@tekgen.BV.TEK.COM> <1990Sep11.034940.16212@ecn.purdue.edu> <1990Sep11.211524.2956@ultra.com>
Sender: news@shamash.cdc.com
Lines: 28

My Kronos 2.0 instant says:

6603 and 6603-Mod-1 Disk Files
Equipment type: DA
Sectors/track:  64 in outer zone
                50 in inner zone
Tracks/device:  2048
Words/device :  7,471,104 (60 bit words)
Max Data rate:  61.1K wds/sec outer zone
                48.5K wds/sec inner zone
Transfer rate:  1.4 usec/word (12 bits) outer
             :  1.8 usec/word (12 bits) inner

I don't have a 6603 platter but my recollection
is that they were more like 1 meter in diameter
and the 6638 platter could have been around 26".
I have some 6638 platters at home so I might
remember to check their size.

There is a story (possibly apocryphal) that at some
site the heads crashed on a 6603 and the motors kept
turning. The friction is supposed to have ignited
a fire on the disk platters which (story has it)
contained aluminum and magnesium. Supposedly the
result was a computer room equivalent of a meltdown.
--
Richard R. Ragan (408) 496-4340
Control Data Corp., Silicon Valley Operations