On Oct 11, 3:47 pm, Rich Grise wrote:
On Thu, 11 Oct 2007 13:23:27 -0700, Half-Nutz wrote:
On Oct 10, 8:33 am, "Joe AutoDrill" wrote:
I wish I still had the two gigantic 12 meg hard drives I picked up in the
80's... 36" long by about 24" wide and about 10-12" thick... I'm sure
there were possibly some huge magnets in there...

"Ernie Sty" wrote in message

A guy I know bid on an old non-working hard drive. It was big, something
like ten inches by maybe 18 inches by three inches. I asked him why he
wanted it, and he said he'd show me.

A few days later, the display on my CRT started wobbling. The guy was
holding a magnet a good six feet away from my monitor and rotating it
slightly. Needless to say, he got it out of the hard drive. He had to
use a ball joint separator to get the two magnets apart. Each one was
about the size of two decks of cards, if I recall correctly.

I never found out what the strength of those magnets was. He soon made
the mistake of holding one in each hand. They got too close together and
in a split second they had collided, nipping off a little of the skin from
his fingers in the process. I figure he's really lucky that's all that
happened. I can think of a number of ways it could have been worse.

He brought in the now-stuck-together magnets and surprisingly (to me,
anyway) their magnetic pull for other objects was very weak, like they
were each absorbing the magnetism of the other. I asked if he was going
to try to separate them, and he said no, and showed me that they were both
cracked.

I think he was, too, a little.

Anyway, that's all the experience I've had with what were to me
monstrously powerful magnets.- Hide quoted text -

I still have a head positioning magnet from a disk drive from the
original Cray1.
The drive was as big as a couple washing machines, and ran on 208V
three phase.
The drive magnets were about 12" X 10" X 10" in a cube.
That beast could heat a house, and had a whopping 300 MegByte. NOT
GigaByte... MegaByte.
When they did seeks, whole buildings could shake. Litterally.
I almost saw a huge old IBM 360 system tip over in the same room when
these drives were installed, from the floor shaking.

Sounds like you've just described a Control Data Magnetic Peripherals
Division FMD ("Fixed Module Drive") drive. I used to work there. The head
positioner test was pretty awesome - it shook about like a washing machine
on "spin".

Didn't Mr. Cray quit CDC to start Cray? I bet he took these with him. Or,
he might have just bought them outright.

Heck, I might have worked on the one that your magnet came out of! ;-)

Cheers!
Rich- Hide quoted text -

- Show quoted text -

Rich..
Seymour left CDC to start Cray..
They had set him up with the "Hallie Lab" where the CDC 7600, and ill
fated 8600 were developed.
There was some conflict, I forget the details, it is better told in
the book "Supermen"

Anyhow, Seymour's house was a few hundred feet from the Hallie Lab. So
he built a new lab on the other side of the driveway, and that is
where Cray Research got started.
A LOT of guys from the 7600 / 8600 project followed as soon as they
had room for them.
I met people that had designed the "six pack" PPU's that you probobly
used to check out the drives, and guys that designed the disk
controllers from the 7600's.

They started with a CDC disk controller, and had a rat's nest of wires
going into Cray designed boards to interface to the Cray channels.
Later, they re-designed the whole disk controller with all Cray parts.
Since it was the same guys re-designing it, it might have had
"similar" logic in it.
They started out with DD19's then later DD29's
he magnet is from a DD19 or a DD29. 300 or 600 MegaBytes (!!)

Later they sank a TON of money into a company called Ibis to make high
performance disk drives, 1200 MegaBytes, and as big as the old CDC
units.

I might even have an old FTU case for the DD19's They made a nice
little tool caddy.
Thanks for the memories!

And you are from the era where they had the ads on TV,
"If you like working with your hands, but don't like to get your
fingers dirty, Call the Control Data Institute"
Ironically, the actor saying those lines is closing the lid on a high
speed Chain printer, one of the nastiest, messiest, horrifying things
to work on, being FULL of ink, all over the printing chain! G

I interviewed when Cray1 serial number 2, and 3 were on the floor, and
stated in time to help check out serial number 5.

Some serious history, and WILD stories from all the people coming and
going, from all the sites around the world.