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Marconi in Computers and Automation

Page history last edited by Alan Hartley-Smith 1 month ago




During the 1950s and 1960s as users of radar systems demanded more and improved performance the development of digital computers provided the means for automatic plot extraction and processing of data to enable better display and control for operators. Marconi Radar Division Display and Data Handling laboratories designed both special-purpose and general-purpose machines using first discrete transistors and then microelectronic circuits to meet this need.


As a result, it produced the world’s first commercially available microelectronic computer – MYRIAD I - which was followed by MYRIAD II, designed on a modular basis for applications not requiring the full facilities of Myriad I, which became the basis of Marconi’s Line Communications Division’s Automatic Message Switching System (MARS). 


Computer graphics was a new technology in which Marconi also carried out advanced development work. It brought enormous benefit to industry by undertaking the routine tasks, which consumed so much time, and revolutionising many industrial professional activities in the same way as the application of automation revolutionised so many industrial production processes.


Initially two new trading divisions Computer and Automation were formed by drawing staff from the established divisions, but changes in the company market focus later led to mergers which resulted in their activities being reabsorbed into a new company trading structure. 



When the computer industry was further rationalised under Tony Benn (originally known as Anthony Wedgwood Benn) to form ICL it was made up primarily from the commercial computer sector.  Real time and military type computer teams such as those of Marconi, Elliott Automation and Plessey were left out of the new company.  It is the view of many that this was a major mistake breaking up any possible synergy between civilian and military research and design.  In the USA that synergy led to important developments and helped them dominate computer advances.  



Marconi Transistorised Automatic Computer (TAC)


This early machine was originally developed by Marconi in 1959 for radar applications. Five were built, and later did find some commercial application.


The Jim Austin Computer Collection here has some good background on the TAC and its impressive 38 years use in the Wylfa Head Power Station.



Marconi ‘igh-speed' Miniature Processor (IMP)


The IMP, shown herewas initially not intended as a commercial computer project.  The research project  was to investigate high-speed logic systems and ferrite core storage techniques - it was the local team who decided to make a computer. It was never manufactured but once it had been revealed in a working condition the decision was taken to design a production machine based on the lessons learned. A unique feature was that unusually both machines worked in asynchronous mode, the time for different activities not being based on a central clock, one of the techniques which enabled the computer to operate at a greater speed than other machines.The result was Myriad I, a computer built into a desk with battery powered backup to support short power failure, for defence and ATC use, followed by Myriad II which was aimed at industrial use such as power stations and was a rack-mounted system. Myriad III was proposed, with higher performance and a much larger core store, but although the design was completed and prototypes made it never went into production as the computer market structure was reconfigured in a company reorganisation.


IMP was transferred to the Science Museum and is still in store there. It may be possible in the future to restore it to operation.[Editors note - see this entry]



The Myriad is born


The first commercially available microelectronic computer was conceived by Marconi in 1965 and described in the January 1965 issue of Aerial here.


MYRIAD I, a very high-speed, on-line, real-time machine, was of such capacity, speed and flexibility that it found an immediate place in a wide diversity of automation systems, being the basis of:


  • The Automated Meteorological System ordered for Sweden
  • The giant Flight Plan Processing System ordered for the London Air Traffic Control Centre
  • The Glasgow Area Road Traffic Control experiment
  • The tracking systems of Britain’s three military satellite communication earth stations
  • The Australian Air Defence System ‘Hubcap’
  • Various research applications including the Central Electricity Research Laboratory, the Royal Radar Establishment and the English Electric Nelson Research Laboratory


Summaries of two market segments can be viewed here: Traffic Control Automation   Design Automation


The design principles were also used to develop the System 4/30 computer for English Electric Leo Marconi (EELM).  However, this was cancelled in its early stages because some important instructions were incompatible with the higher models of the System 4 range namely the 4/50 and 4/70.


Towards the late 1960s the Computer and Automation Divisions were growing well and their organisation (1969) can be seen here with their main applications here.





Model No.

Approx. Date

Description Details Comments
S3304  1965 Myriad I Digital Computer here  
L4001  1967 Myriad II Digital Computer  here  
  1969 Myriad III Digital Computer  here  
  1965 Peripheral equipment  here  
  1965 Myriad Software  here  
X2000 Series 1968 Data Displays  here  
X4000 Series  1969 Video Data Terminals  here  
  < 1968 Myriad Core Disc Store Operating system  here  
  < 1968 Acoustic Traffic Sensor  here  



Reference material


Myriad I description and engineering detail

Myriad II description and engineering detail

Myriad III description


An article on building the Myriad taken from the October 1966 issue of Marconi Companies and Their People click here


Computing History

National Archive



Marconi Locus 16


In the early 1970s Marconi Radar built its own mini computer, the Locus 16, for use in radar systems. A paper giving further information on the use of Locus 16 in Marconi radar applications is here .
More information




LEO Computers


Information relating to Leo Computers has been placed on a new page here.






There are a number of sites holding related information of which these are examples:


An extensive history of the history of computing in Staffordshire - specifically the English Electric Computer works at Kidsgrove, Staffordshire


One example of cooperation was the use of tabular displays in the Park Gate steel works system supplied by EE - a film is available here 


IT History Society


Computer Conservation Society


Vintage ICL Museum








Article description 


1966 Building the Myriad here
1967 Confrontation with a computer here
1967 Putting the Go in Glasgow here
1969 Self-repairing computers here
1969 Software - the life of the computer here
2002 History of the Kidsgrove Works (Archive copy) here






This page includes various announcements, papers, radio talks and so on.


In February 2020 the Editor delivered a presentation on Marconi computing to the North West Group of the Computer Conservation Society - the PowerPoint file is available here. This was revised for a general audience and delivered during the Essex2020 Melba Centenary celebrations - a recording is available here. By invitation it is to be repeated for the London Group in January 2024 and will be delivered by Zoom.



As well as engineering some significant staff were involved - a list is being put together.

David Stone


This wiki is one of a series recording the history of the Marconi Company from its formation starting from Family


Statement of intent





Comments (3)

David Samways said

at 6:24 am on Mar 4, 2017

A Marilyn Smith has just asked to join the Research and Computer Wikis She says she joined the company in 1968 and knew Norman Huttly, David Gager, Don Gill, Peter Sizer. Anyone know of her?

Alan Hartley-Smith said

at 5:53 pm on Jul 27, 2017

Test comment as agreed

Ian Gillis said

at 5:58 pm on Jul 27, 2017

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