[GreenKeys] Reader-run relay installation

[Jones, Douglas W]

I've completed the installation of a reader-run relay in the CCU
of the Model 33 we're rebuilding.  Photos of the completed job
and links to the documentation are here:

-- http://www.cs.uiowa.edu/~jones/pdp8/UI-8/log.shtml#2014-05-01

Given the incredibly poor quality of the photo in the preserved
copy of DEC's instructions for installing the relay, I hope
these photos help others, and also, I note that our cable routing
was at least reasonable.

I debated lacing my wires instead of using zip ties, but DEC
always used zip ties in their work.  I also debated running the
wires on the right side along or even laced to the original TTY
wiring harness, but the length of the salvaged wire from the
relay to plug 4 was too short for that, so I did my best to follow
(approximately) DEC's original wire path.

Yes, I know how to lace cable.  And in other recent rebuilding,
I had to use that skill.  The motor on the Tally 424 "high speed"
paper tape reader had bad wires (crumbled rubber insulation) so
I had to replace them.  This involved replacing the lacing on
the motor windings.  The photo here shows that job in progress,
the new lacing job started and the old one still not fully removed.

-- http://www.cs.uiowa.edu/~jones/pdp8/UI-8/log.shtml#2014-04-25

The lacing pattern on the motor windings is not just a double
spiral (that's what I thought it was on first inspection.  It's
more complex, and the complexity is all out of sight, and tricky
to recreate.  The rebuilt motor runs well, almost silently and
warm but not hot.

		Doug Jones
		jones at cs.uiowa.edu