Atari ST diskettes

[Paul Koning]

> On Dec 7, 2020, at 2:50 PM, Van Snyder via cctalk <cctalk at classiccmp.org> wrote:
> 
>> ...
> 
> 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 Model II added hardware add/multiply. 

> 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