Mailinglist Archive: opensuse (4020 mails)

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Re: [SLE] new v9.2 is out-terminal question
  • From: Carl Hartung <suselinux@xxxxxxxxxxxxx>
  • Date: Wed, 27 Oct 2004 16:43:41 -0400
  • Message-id: <1098909820.20083.21.camel@xxxxxxxxxxx>
On Wed, 2004-10-27 at 15:09, Randall R Schulz wrote:
> Darrell,
>
> On Wednesday 27 October 2004 11:16, Darrell Cormier wrote:
> > ...
> >
> > Just curious if any of you have every worked with a machine that used
> > core memory. If I remember correctly you basically had a cage of
> > "boards". Each board was an x-y grid of fine wire and around each
> > intersection of the wires was a ring of some ferrous oxide material.
> > A current was applied to a certain x-y coordinate to charge the ring
> > thus representing a binary 1. This was a system that had a
> > destructive read which required you to write back what you just read.
> >
> > I have never used one myself but one of my college instructors had
> > one of these cages of core memory modules from a machine he had used
> > in his youth. Quite interesting.
>
> We had such a museum-piece in the Computer System Lab at the University
> of Wisconsin when I worked there in the late 70s and early 80s, but no
> computers that used it. The oldest computer we had was a PDP-11/20
> equipped with a fixed-head hard drive, a card reader and a very
> low-resolution CRT monitor.
>
> Core memory was interesting in a lot of ways. It was horribly slow by
> today's standards and likewise the density was abysmal by comparison
> with any kind of solid state RAM. Reading it destroys the stored
> memory, so the controller always had to write the value back. On the
> other hand, real core memory is non-volatile, so you could power the
> machine down and when you next turned it on, the contents of main store
> would be what they were when you shut it down.
>
>
> > Darrell C.
>
>
> Randall Schulz

My old boss (this was circa '89-'90) had worked at IBM in the 60's when
toroidal core memory -- hand sewn in India, btw -- was leased (not sold)
to the Wall Street crowd for $250,000 a year per MB. He described
having to duck his head while walking through the mass storage rooms
with machinery whirring and media reels screaming past overhead on
tracks. He said if you got hit with one of those things it'd plant you
on the "far wall." Now you can't give a 1 MB SIMM away and you can
barely squeeze your fingers into a pc case to do any work! Just my 2
cents on this one...

regards,

- Carl


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