Circuits/arithmetic units

History of IBM

Standard Modular System was developed in the late 1950s and superseded the old vacuum tubes. The Standard Modular System (SMS) was an innovative system of standard transistorized circuit boards and mounting racks developed by IBM in the late 1950's.

It was superseded by Solid Logic Technology (SLT).
SMS cards were constructed of individual components mounted on single circuit board, mainly forming the central processor unit (CPU). A SMS card usually consists of about 30 components.

Intention of the developers from IBM, using only 100 different types of cards for all imaginabel cases. This plan ends in smoke – the neccessary amount of cards increased rapidly. Reason for this were the high number of different applications.