Subject: Re: Remembering RAMAC
From: "Dwight K. Elvey" <dwight.elvey at amd.com>
Date: Fri, 27 May 2005 09:44:38 -0700 (PDT)
To: cctalk at
classiccmp.org
From: "Vintage Computer Festival"
<vcf at siconic.com>
---snip---
I was thinking more in terms of space. A disk is much more efficient in
this regard. You can stack N times the number of disks in the same space
that a drum takes up.
The problem with disk, of course, is the variable BPI.
Today, with the electronics so cheap, the CD-ROM is made
with a spiral track and it runs at a constant BPI by
changing the rotation speed as it reads the disk.
Dwight
The big advantage and values of drums was high inerta plus parallel
heads. Some designs were 16bits wide (maybe there were wider)
plus timing tracks. So while small ( I remember the 128kw
swapping drum on the KA10s) they were extremely fast.
Of course late in the game was the 32kW RS08 disk for the PDP8
systems. Small but very fast word wide storage.
Every so often I get the itch to find a small drum and get it
working.
Allison