13 Aug
2013
13 Aug
'13
6:44 p.m.
On 8/13/13 4:15 AM, "Chris Elmquist" <chrise at pobox.com> wrote:
On Tuesday (08/13/2013 at 08:46AM +0200), Pontus
Pihlgren wrote:
"Knob twiddlers" were unlikely to be a problem with an expensive machine
like the KI, which would have been in a machine room with access limited
to people who should know better. Others have talked about usage, and I
won't repeat since they're right. :-) Margin testing was a common
feature in this era. Our PDP-7 has it, too. It seems later machines with
higher integration (e.g., PDP-11) used it less often, as the philosophy
was beginning to be "replace boards until it works again". -- Ian
Last time I saw an object for sale was a KI front panel:
http://www.ebay.com/itm/Vintage-DEC-PDP-10-KI-10-Computer-Console-Panel-S
uper-Rare-/130768694290
Interesting pictures. I am curious why machines of this era often have
a "VOLTAGE" adjustment on the front panel? Was it really neccessary
for an operator to adjust some voltage setting as the machine ran thus
requiring that adjustment to be easily accessible on the front panel?
What is it about the design that requires this?
Why wouldn't the voltage adjustment be on the back or down inside where
some knob twiddler can't get to it?
It looks like the knob turns a variac so it's adjusting an AC voltage
while the meter reads DC... so is it perhaps adjusting the AC mains
input to a/the power supply, because the mains voltage wasn't stable?
The variac seems a little small for that but ...
Curious.
--
Chris Elmquist