Manchester "Baby" Computer


Reconstructed Manchester Baby
The Manchester Baby (or Small Scale Experimental Machine) was the world's first stored program computer and was built to demonstrate a CRT development. The CRT screen's phosphor persistence (and charge) was utilised to continuously store, read and rewrite digital information on a grid.
The numeric result of the stored computer program would be read out on the bottom line of the output CRT grid in binary. Four CRTs were used for data storage, each with a different function. The CRT developed by Williams and Kilburn would be licensed to IBM for its 701 and 702 computers from 1952 onwards. The IBM 701 used 72 Williams tubes for 1024 bits of storage each.

Ferranti MK 1 Logic Element
The Ferranti MK 1 was the commercial computer developed from the Manchester Baby (and the subsequent Manchester MK I). It used 1600 x EF50 pentode valves (tubes) and 2000 x thermionic diodes for the logic elements (two logic circuits shown on the left).

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