4 Feb
2016
4 Feb
'16
6:57 p.m.
Some models of 3420s were 7 track.
--
Will
On Thu, Feb 4, 2016 at 9:56 PM, Jon Elson <elson at pico-systems.com> wrote:
On 02/04/2016 07:48 PM, Mike Loewen wrote:
I'm trying to identify a system which appeared in "The Killer Elite"
(1975), with a room full of tape drives and a couple of terminals:
http://q7.neurotica.com/killer-1.png
http://q7.neurotica.com/killer-2.png
http://q7.neurotica.com/killer-6.png
http://q7.neurotica.com/killer-9.png
The drives appear to be IBM 3420s, but with an additional box on top,
labeled "SMS". The system itself doesn't appear in any of the shots. Some
sort of IBM 370, perhaps?
I'm thinking they might be 2420's. They have a "9" label on the
head cover.
This is to distinguish 9-track from 7-track drives, I don't think they put
those labels on 3420 drives.
The drive addresses are 5xx, meaning they are attached to channel 5 on the
CPU. That is not impossible on a 360, but few 360's could handle that many
channels. The cluster of 3270's also suggests a 370 system, although they
certainly could be used on 360's.
The SMS boxes displayed the volume label of the tape to mount. Mounting the
wrong tape was a BIG problem in large systems, so a number of vendors came
up with these sorts of schemes to try to reduce those errors.
Jon 
