7 Dec
2020
7 Dec
'20
12:15 p.m.
On Dec 7, 2020, at 2:50 PM, Van Snyder via cctalk
<cctalk at classiccmp.org> wrote:
The Model II added hardware add/multiply.
...
One of my friends changed the tables in a 1620 to do octal arithmetic,
for telemetry processing.
Speaking of those tables, do you remember why the 1620 was called
CADET? Not because it was a "beginner's" or "novice" computer. It
was
an acronym for "Can't Add; Doesn't Even Try." The Computer History Museum in Mountain View,
California has a 1620
that worked for a time. They had a problem with cooling the core
memory, which they could probably repair.
Or perhaps heating. I remember that our college 1620 Model II needed a couple of minutes
after power-on before it would be willing to operate; supposedly that time was spent
waiting for the heaters in the core memory to bring it up to operating temperature.
Apparently timing and/or signal levels in core memory are fairly sensitive to temperature,
so keeping them consistent is helpful. It isn't common to select a temperature well
above ambient and use heaters to do that, but it isn't totally strange.
paul