SCM Marchant Cogito 240 Electronic Calculator


This ten-key, non-printing electronic desktop calculator performs the four arithmetic operations of addition, subtraction, multiplication, and division. The factors and results are stored in three registers, two of twelve-digit capacity and the third, of twenty-four digits. The content of these registers appears in three rows on a cathode ray tube display. The top row (K) shows the entry from the keyboard, the second row (Q) the second factor or the quotient, and the third row (P) the total, product, or dividend.

In front of the display is the keyboard, with an array of digit keys at the center, keys for arithmetic functions and memory on the right, and on the left reset, register transfer, register entry, recall, and exchange keys.

A mark on the left front of the machine reads: SCM MARCHANT. A mark behind the keyboard and below the screen reads: COGITO 240.

In the summer of 1965, the SCM Marchant Division of SCM Corporation announced that it would begin to sell the company’s first electronic calculators that fall. These were the Cogito 240 and a similar machine, the Cogito 240SR, which also had the ability to take square roots. The 240 was to sell for $2,195, and the 240SR for $2,395. The machines were manufactured at a company plant in Oakland, California.

According to Bensene, the machine was designed by computer pioneer Stanley Frankel, who had worked on the Manhattan Project, run programs on the ENIAC computer, headed the Computation Laboratory at the California Institute of Technology, and contributed to the design of minicomputers such as the LGP-30 and the Packard-Bell PB-250. Frankel worked on the design at Computron Corporation, a subsidiary of the California firm of Electrosolids. Not long after the British firm of Sumlock Comptometer released a desktop electronic calculator in 1961 (see the Anita Mark VIII), SCM acquired Computron Corporation, and Frankel and his team moved there to develop the Cogito 240.

The calculator was quickly replaced by other electronic calculators in the SCM line. SCM dropped out of the calculator business entirely in 1972.

The object has a black plastic cover which is stored separately.


R. Bensene, “SCM Marchant Cogito 240SR Electronic Desktop Computer,” at the website The Old Calculator Museum, accessed March 28, 2013.

SCM Marchant, Cogito 240-240SR Service Manual & Parts List, Oakland, Calif.: SCM Corporation, 1965. This is 1979.3084.72.

W. D. Smith, “Electronic Calculators Gaining,” New York Times, August 7, 1965, p. 25.

“Presenting a new, highly advanced electronic calculator the Cogito 240,” Los Angeles Times, June 17, 1965, p. B10. Similar advertisements ran in the Chicago Tribune, Washington Post, and New York Times.

Date Made: ca 1966

Maker: SCM Corporation

Location: Currently not on view

Place Made: United States: California, Oakland

Subject: Business


See more items in: Medicine and Science: Computers, Computers & Business Machines, Desktop Electronic Calculators


Exhibition Location:

Credit Line: Gift of Business Equipment Division, SCM Corporation

Data Source: National Museum of American History

Id Number: CI.335373Accession Number: 318944Catalog Number: 335373

Object Name: electronic calculator

Physical Description: plastic (overall material)metal (overall material)Measurements: overall: 10 1/4 in x 15 in x 20 1/2 in; 26.035 cm x 38.1 cm x 52.07 cm


Record Id: nmah_334770

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