This accepts 44-pin vector boards.
The board on the left (socket 7)
adapts to a 50-pin IDC ribbon
cable. The power buss carries
+5v, +15v, -15v, +30v and (Ret/Gnd).
All sockets are wired identically.

Visible on the right is the buss
termination network.
It is a 100 ohm resistor in series
with a 100 pF capacitor tied from
(ret/gnd) to each of the buss signals.
This was done to suppress reflections
and "ringing" which had been causing
some problems.