MuseumWeek #TechnologyMW – Computing from the 60s to the 90s

A computer sitting on top of a deskDescription automatically generated

The IBM 700 series is a series of large-scale computer systems that were made by IBM throughout the 1950s and early 1960s. The IBM 705 was one of the most powerful data processing systems available in the 1950s. Operating according to a program, this computer was able to perform a series of arithmetic and logical operations automatically and at speeds which made it capable of 240,000 decisions in 60 seconds.

Data was input most commonly using a magnetic tape, but entry could be affected by a punched card reader or from the operator’s console. At the start of the processing procedure, the program was read into memory from the magnetic tape, then the computer processed everything without any human assistance. The data is represented by a variable-length string of characters terminated by a record mark. It has one accumulator, 14 auxiliary storage units with 16 characters and one auxiliary storage unit of 32 characters. It held 20,000 or 40,000 or 80,000 characters of core memory and has a character cycle rate of 17 microseconds or 9.8 microseconds. The 705 use channels with a 7-bit interface.

The IBM 705 system was used at the Worthy Down site when the Royal Army Pay Corps established the Electronic Accounting Development Unit in 1960. This computer system was used to process the 1961 UK census electronically for the first time. The British Army were also one of the first in the country to use a computer for processing pay. As well as this logic module, in the AGC Museum archive there are a number of punch-card tracer cards, which have basic information like date of birth, joining date, and sometimes location and postings. Without the computer they are quite arduous to read but there is a way to do so!


This computer was used in the First Gulf War (1991). It is an ‘out of office’ unit and was designed to be able to be dropped from helicopters without damaging it.

We have a lot of visitors come into the museum and show their children that they used to use something like this! When you consider how small computers are now even this seems large (although tiny compared to the IBM 705!)

The air campaign of the Gulf War was an extensive aerial bombing campaign in 1991. The Gulf war is sometimes referred to as the ‘computer war’ because of the increase in advanced computer-guided weapons and munitions used in the air campaigns.

1991 ‘out of office’ computer

Computer technology has moved incredibly quickly, with computers going from needing a whole (large!) room to being easily portable inside your pocket (a mobile phone). The British Army made sure they were at the forefront of this technology and the RAPC were one of the first to revolutionise how pay was processed.