Joe Pfeiffer wrote:

Yes, seven platters. Reminds me of the old 12 inch winchester with
the removable 10? platters.

How did they manage a removable platter in a Winchester drive? It would
seem like removing the whole sealed unit would leave nothing but a
circuit board behind...

You're showing your lack of age.

The whole platter assembly was removable. It came out with a plastic
bell that you could store separately hence you could replace "drives"
(well, the platter packs since the "drive" was the washing machine that
stayed in one place).

HDD platter packs:
https://www.cs.auckland.ac.nz/histor...hsDiskPack.jpg
http://i.stack.imgur.com/1hFxX.png

That one you inserted the pack into a "drive" (about the size of a small
washing machine), twisted on the handle, removed the plastic shell, and
closed the drive. As to its size, see the comparison he

http://tr2.cbsistatic.com/hub/i/2006...8646b/3373.jpg

Rack-mounted sliding HDD:
http://www.edwardbosworth.com/CPSC21...s/image006.gif

That one only had 1 or 2 platters, the rack-mounted drive slid on rails,
and you plopped the platter set into the drive (the top was the seal),
and slid the drive back into the rack.

Because of the size, thickness, and weight of the platters, especially
for multi-platter packs, they were only supposed to be spun up when
stationary. A U.S. sub once forgot to spin them down before leaving
port, the drive assemblies broke lose from the floor bolts, and the
thing went bashing around the room.

The air contamination problem was eliminated by having both the platters
and head assembly sealed inside a plastic shell that you twisted into
the drive which made electrical contacts to control the heads. Where
you screwed the pack into was the motor to spin the platters. See
http://upload.wikimedia.org/wikipedi...Module.agr.jpg.
Think about trying to tote one of these with your laptop.

History of magnetic drives
http://en.wikipedia.org/wiki/History...ic_disk_drives

At the opposite spectrum were the microdrives. I believe they were
originally planned for pre-installation on motherboards to provide some
starting storage capacity. 1-inch platters about the size of a quarter;
http://www.tommytrc.com/sparkatopia/...8d31d484a8.jpg.
and http://en.wikipedia.org/wiki/Microdrive.

In the old movies showing computers, HDAs were boring to film because
nothing could be seen, so they should you a bank of old tape drives and
some maintenance panel rarely touched with blinking lights and switches.
The computer room was so noise due to drive motors, fans in the
equipment, and high-volume air flow A/C that I used to wear my hearing
protectors that I used at the gun range. It saved from hearing loss.