4 Oct
2024
4 Oct
'24
3:30 p.m.
On 10/4/24 00:07, Christian Corti via cctalk wrote:
On Wed, 2 Oct 2024, Tom Gardner wrote:
We did not have the direct seek feature on the 1311 on our CADET back
then. Figure that it takes additional logic to figure out "where am I
now and where do I want to go?"
So, a feature.
--Chuck
Speaking of high profit margins: on the 1620,
there was an extra cost
option called "direct seek". I don't know if involved a jumper cut or
some actual circuitry (an adder, most likely). We didn't have that,
and the result is that a seek from cylinder x to cylinder y was done
by a full retract to cylinder 0, followed by a seek out to y. It was
amusing to watch the shaking resulting from a simple "incrementing
seek test" -- seek to cylinder i for i = 0 to 99. Those last few
seeks would take the better part of a second.
Here's a link to a video that I took last year of a 1311 doing seeks (it
is running on a 1401): https://www.youtube.com/watch?v=LXDVRP9pfyw