wrote in message
...
On Sun, 9 Dec 2007 22:10:36 -0800, "Calif Bill"
wrote:

IBM had better salesmen also. Macy's San Francisco was looking at new POS
(Point of sale) system and the NCR terminals were better and smaller wire
to
run. The NCR sales guy told Macy's that they would have to run the
terminal
wires in conduit past all the florescent lights, and the IBM sale guy said
not needed with the IBM terminals. They needed the conduit also, but the
IBM guy knew the fire department required the conduit. So Macy went IBM.


It was a myth that flourecent lights affected the baseband LAN IBM
used on the 46xx registers and the S loop on the 36xx registers was
tougher than that.

I did a lot of tests in the lab on both.
The S loop ran so slow you couldn't break it. We wired with STP and it
would run on doorbell wire. The baseband LAN run with CAT3 was immune
to anything a ballast could throw at it. It only ran at 1mz. We ran
UTP all over shopping malls and fast food joints here without much
regard to anything. (no conduit, just "plenum rated cable") They
worked fine. Later when I acually got certified as an electrical
inspector I know most of that wiring was not legal.

I think the IBM salesman must have known that the San Francisco regulations
required conduit. So he had the best of all worlds. A good LAN and the
ability to say no conduit required even if it was. He was just a better
prepared peddler.