Standard Telephones and Cables Limted, London

STC was a large British engineering firm that attempted to enter the computer business by producing a machine, the Zebra (Zeer Eenvoudige Binaire Rekenautomaat) originally designed by the Dutch computer pioneer W. L. Van der Pool.

It was an interesting architecture with a large instruction set. While there was a standard set of operations, individual circuits of the machine could also be activated (and often were) by turning various bits of an instruction on or off. This led to some programs that were challenging to understand and/or debug. Another interesting feature was a rotary telephone dial that could be used to enter small amounts of data from the console. The machine used vacuum tube technology with a drum memory.

Announced in 1956 and designed as a scientific machine, the Zebra was actually delivered two years later. A number were sold in Britain, Europe and British Commonwealth, but it never became a popular. It was soon surpassed by transistor and core memory machines.