IBM Mainframe Logic Cards

IBM Standard Modular System (SMS) Card
The Standard Modular System for mainframes was introduced by IBM in the late 50s for the 7030 Stretch program. The card on the left is an IBM SMS card post 1969 even though the card format had changed with the System/360. This card is from a 2420 tape reader. Tape machines and other peripherals kept the SMS format and the component technology longer.
The NPN transistors are date code 1970 but are IBM 030 and 044 transistor models defined in the late 1950s.
The IBM chrome coloured module on the right of the card is SLT (Solid Logic Technology) format.


Later IBM Format Card
Monolithic System Technology (MST) was introduced by IBM in 1968 and first appeared in the System/370. It replaced the earlier discrete transistor and diode logic SLT, SLD and ASLT hybrid logic with monolithic circuits, still on ceramic substrates in the same IBM package format.




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