[GreenKeys] LESU 13

[Jim Haynes]

Seems like the diagrams on rtty.com are readable - at least that's what
I think I was using rather than digging out a hard copy that I have
buried somewhere.

The very early Model 28 sets had three terminal strips of 10 terminals
each.  Later models have two strips of 20 terminals each; and there was
a mod kit to mount two strips in an old cabinet designed for three.
So I guess at some point someone decided that 30 terminals was not enough
and went to 40.  On the schematics these are designated C-1 through C-40.

The A terminal block is the selector magnet terminal block in the LESU.
The B terminal block is called a line-test-key block in the LESU, but
lots of sets do not include a line-test key.  A and B are at the left
hand end of the LESU as it is installed in the cabinet.

The D terminal block is the motor control block in the LESU, and the E 
block is the power terminal block.  These are on the right hand end of
the LESU.  F is the keyboard connector and R is the typing unit connector.
S is the motor terminal block on the base or keyboard.

Off the top of my head I don't know what is the difference between the
common LESU7 and the LESU13.