Analog Shift Register
=====================

Uses the 1075SR board - from 1975 until at least 2000, and probably still in
use.  The Dual ASR is just two of these boards stacked up behind the panel.

Schematic and other information are available in a Synapse artice, kindly
provided by Cyndustries here: 

http://www.cyndustries.com/synapse/synapse.cfm?pc=35&folder=sept1976&pic=19
http://www.cyndustries.com/synapse/synapse.cfm?pc=35&folder=sept1976&pic=20
http://www.cyndustries.com/synapse/synapse.cfm?pc=35&folder=sept1976&pic=31

The schematic is largely correct, except C1 isn't present and there apepars
to be no place where it could go - unless Serge used to solder it on the back.
R19 and C14 are reversed - R19 goes to pin 4 and C14 to pin 2 of the LM3900N,
but this makes no prectical difference except duting fault-finding.

Pins 6 & 12 of U2 (4066 or 4016) go to 0v

Pins 1, 12 and 13 of the LM3900 are left unconnected.  This would be a
disaster with any other sort of opamp, but isn't a problem with Norton opamps
like the LM3900.

Recent version have trivial differences - leave R26 out, replace the CA3140s
with CA3130AE, and replace the 4066 with 4016BE, but are otherwise as per the
schematic.

Pad numbering is:

A - Sample In
B - Output 1
C - Output 2
D - Output 3
E - End Of Cycle/Aux Pulse/Pulse Out
F - Trigger In/Pulse In

W - 0v
X - +12v

Note: no -12v supply is needed.