block contained transistors, diodes and resistors and carried out basic computer logic functions such as AND and OR
FYI I commissioned a (new) NORLOG-based safety interlock system for the Active Maintenance Unit at
These NORLOG blocks were made for EE by WELWYN Electric of Bedlington, Northumberland for the control gear division.
( The original NORLOG was developed at EE Whetstone for the Wylfa Power Station on Anglesey.)

The company is still able to manufacture these blocks on order of a certain size.
Many thanks to Graeme Murphy a Systems Engineer at WELWYN for the information on these blocks.