Delete comment from: Ken Shirriff's blog
The "pseudo-integrated-circuits on small boards" were also used by British company Elliott Automation in the 1960s for their 920B and 903 range of transistorized computers. They referred to them as "logic sub-assemblies" or LSAs and they were the basic field-replaceable unit -- technicians were expected to swap out defective LSAs instead of repairing them.
"The CPU of a 920B/903 contains 75 circuit boards, measuring 8˝x5˝ (20x13cm). Most of
these are populated with “Logic Sub-Assemblies”, typically 14 to a board. Each LSA can
hold up to 3 transistors plus other components, and so can implement up to 3 “basic logic elements” using Diode-Transistor Logic. For example, LSA01 implements three 2-input NAND gates, LSA03 is a 4-input NAND gate and two NOT inverters."
-- www.tjfroggatt.plus.com/CCS-E5X2.pdf
The 920B/903 was succeeded by the 920M which implemented the same architecture with DTL integrated circuits, massively reducing the size of the machine.
Jun 17, 2021, 6:14:53 AM
Posted to Inside a transistorized shift register box, built in 1965 for Apollo testing