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 YEAR: 1967
 ITEM: Analog Computer
 COMPANY: I-Cor Systems
 COUNTRY: England
RARITY: Exceedingly Rare   Click here for further information on our rarity scale Information on the rarity of this item is unknown.

MAC-1 Mini-Analog Computer


There is very little information about this computer. It appears to have been designed to teach kids how to do math...the input dials certainly resemble a slide rule. It was offered as a kit (which you would put together yourself and that usually required some soldering) or you could get a fully-assembled version. The original cost for the kit was 3 10 shillings 6 quid, while the "built and ready for use" MAC-1 sold for 3 19 shillings & 6 quid1.

The MAC-1 was developed by I-Cor Systems in England. Tracking down the date for this computer was difficult. The company that made the MAC-1, I-Cor Systems, also sold the Digi-Comp 1 in 1963 which was developed by ESR in Boston.2 So that gave us a starting place on the date. We found four I-Cor Systems ads; one ad for the MAC-1 from 1967 and two ads for Digi-Comp 1 and one ad for the MM Computer, all from 1967. Nothing before and nothing after.

The first small ad we found was for the Digi-Comp 1 and was buried in the back of the August 1967 issue of Practical Wireless magazine published in England. The ad was oddly titled "Digital Trial" which may be a reference to a trial offer but who knows. Another ad for the Digi-Comp 1 appeared in Practical Electronics magazine in April 1967.

We finally found a small ad for the MAC-1, again buried in the back of Practical Wireless December 1967 issue; this time the ad was entitled "Christmas Computer". Given the description of this computer in the ad (see just below), I'm really glad my parents got me a Davy Crockett record for Christmas.

According to the ad, "Just think...with this desk-top mini-analog computer you can multiply and divide, take square roots or powers, and do log operations--simply by turning the dials and keeping your eye on the null meter. The Instruction Manual covers MAC-1's applications in electronics and physics, engineering and trigonometry."

Thought we were all done? Nope. This is one of the reasons I find researching these old computers so much fun...I came across an ad in Meccano Magazine which was a magazine dedicated to building all sorts toys and science projects made by the Meccano Company. This particular ad was for a computer we had never heard about, the MM Computer. Hopefully, we will find more information on this and include it in the collection at

All the ads were in magazines from 1967 which is why we are comfortable citing that as the year in which the MAC-1 was made. The address for I-Cor Systems was 18 Stamford Hill, London for both the Digi-Comp 1 ads (1967) and for the Meccano Computer (May 1967). However, the address changed to 4 Manor Road, London in the MAC-1 ad (Dec. 1967).

1After the Norman Conquest in 1066, the pound was divided into twenty shillings or 240 pennies. It remained so until decimalization on 15 February 1971, when the pound was divided up as it is still done today. Thanks to Project Britain


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Click on any of the images below to see the slideshow.
Front Front with cover removed View with ruler Top right corner Close up of voltage meter Close up of two bottom input dials Back up upper input dial Inside view: Back of lower left dial Inside view: Back of lower right dial Inside view: Back of voltage meter, shunt and zero button Inside view: Overall