Drums

From: John Lawson <jpl15_at_netcom.com>
Date: Tue Apr 18 10:33:15 2000

On Tue, 18 Apr 2000, Hans Franke wrote:

>
> > I think I heard somewhere that magnetic drums are somewhat like core memory,
> > i.e. they retain their contents when shut off...
>
> Well, Drums are just a spcial kind of disk - it's a
> geometrical phenomena - a disk where all tracks have
> the same length :=)

   Which is why we still refer to disk data structures as
'cylinders'... on the surface of a drum, that's the geometric shape
they occupy.

  On my old Bendix G-15, the clock tracks were also on the drum,
allowing the use of a standard 1/4hp induction motor. I have also
seen reference to slow-cycling a drum computer by disconnecting the
motor and turning the shaft by hand.

  And now they have 340M hard drives built into FlashCard memory
chips for my digital camera......


   Cheerz

John
Received on Tue Apr 18 2000 - 10:33:15 BST