Glen Slick wrote:
> Anyone know what this is? Litton Systems?
>
> http://home1.gte.net/~gslick/drum.jpg
I would assume it is a mag drum unit ;-) Made, perhaps, by Litton?
Drums, were the ancestors of disks, same basic principle of operation:
read write head near moving surface of magnetic material. Drums were
developed before disks, I suppose they were easier to construct. They
typically have faster access times than disks (they were usually
constructed with one head per track though moving head disks did exist).
The superior storage density of disks cause dthem to displace drums in
the 60's and 70's. Drums continued to be used for a time as backing
store or fro VM systems.
Interestingly (for some) there were machines built in the 50's whose
main memory consisted of drums. On some of those those machines, each
instruction would include the address of the next instruction to be
executed so that program execution could be optimised.
-- hbp
Received on Thu Oct 03 2002 - 03:09:00 BST
