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From: mo@messy.bellcore.com (Michael O'Dell)
Newsgroups: comp.arch
Subject: Re: weird word lengths
Message-ID: <27527@bellcore.bellcore.com>
Date: 4 Oct 90 12:19:02 GMT
References: <2721@crdos1.crd.ge.COM> <12857@encore.Encore.COM>
Sender: news@bellcore.bellcore.com
Reply-To: mo@messy.UUCP (Michael O'Dell)
Organization: Center for Chaotic Repeatabilty
Lines: 21

Best place to look is the old bit-serial wonders like the venerable
Bendix G15 (looks remarkably like a Dr. Pepper vending machine of
that era).  If memory serves me, it had 27 bit registers or some such.
I never programmed one; just admired people who did.  the memory
was a magnetic drum, but probably not like you think. It didn't
have addressing like we think of a disk, the rotating surface was
used as a delay line: two sets of read and write heads separated by
about 45 degrees.  the "long lines" were between them on the outside
of the 270 degree segment, and the "short lines" wwere between them
on the 45 degree side.  Starting an idle G15 was a real hoot! You opened
the right bay of the machine (swung out like the doors on a batwing 
Lincoln Continental), reached in side and found the flexible coupling
between the motor and the drum, and grabbed it gently giving it a few
turns. this released the stiction so the motor didn't rip the heads off
when it started.  It reminded me very much of a hammond organ in that
once you got the drum coasting along, you hit the starter switch and
the motor groaned to life and spun up to speed.

anyway, i think this satisfies "weird."

	-Mike