English Electric System 4
Encyclopedia
The English Electric
(later ICL) System 4 was a mainframe computer introduced in the mid-1960s. It was derived from the RCA Spectra 70
range, itself a clone of the IBM
System 360 range. The models in the range included the System 4-10, 4-30, 4-50 (practically the same as the RCA 70/45), 4-70 (designed in English Electric) and 4-75. ICL documentation also mentions a model 4-40. This was a slugged version of the 4-50, introduced when the 4-30 (intended to be the volume seller) was found to be underpowered and had to be withdrawn. The 4-10 was introduced as a satellite computer, but demand was very low, so it was withdrawn. Only the 4-50 and 4-70, and their successors, the 4-52 and 4-72, sold in any numbers. A slugged 4-72 (the 4-62) was introduced for sale in Eastern Europe.
The machines were essentially multi-programming batch computers. The System 4-75 was introduced in an attempt to cover the real-time/time-sharing market, but few were sold. One System 4-75 was used by the English Electric Computer Bureau subsidiary to develop and run the internally developed Interact 75 suite of time-sharing commercial packages for payroll and financial ledgers, but this proved unsuccessful, and the project was soon closed. System 4 proved itself to have very efficient communications and was the basis for several successful real-time processing applications.
English Electric
English Electric was a British industrial manufacturer. Founded in 1918, it initially specialised in industrial electric motors and transformers...
(later ICL) System 4 was a mainframe computer introduced in the mid-1960s. It was derived from the RCA Spectra 70
RCA Spectra 70
The RCA Spectra 70 was a line of electronic data processing equipment manufactured by the Radio Corporation of America’s computer division beginning in April 1965...
range, itself a clone of the IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
System 360 range. The models in the range included the System 4-10, 4-30, 4-50 (practically the same as the RCA 70/45), 4-70 (designed in English Electric) and 4-75. ICL documentation also mentions a model 4-40. This was a slugged version of the 4-50, introduced when the 4-30 (intended to be the volume seller) was found to be underpowered and had to be withdrawn. The 4-10 was introduced as a satellite computer, but demand was very low, so it was withdrawn. Only the 4-50 and 4-70, and their successors, the 4-52 and 4-72, sold in any numbers. A slugged 4-72 (the 4-62) was introduced for sale in Eastern Europe.
The machines were essentially multi-programming batch computers. The System 4-75 was introduced in an attempt to cover the real-time/time-sharing market, but few were sold. One System 4-75 was used by the English Electric Computer Bureau subsidiary to develop and run the internally developed Interact 75 suite of time-sharing commercial packages for payroll and financial ledgers, but this proved unsuccessful, and the project was soon closed. System 4 proved itself to have very efficient communications and was the basis for several successful real-time processing applications.