Image Courtesy Galerie Alte Technik

Anita C/IX (Mark 9) Electronic Calculator

Thanks to the generosity of a kind fan of the Old Calculator Web Museum, we are expecting delivery of a wonderful old Anita Mk 9. Sincere thanks to Mr. Richard Jeffrey-Gray for making this acquisition possible. The calculator will soon be making its way from the United Kingdom to its new home in the Old Calculator Web Museum.

The Anita C/IX (also known as Mark 9 or Mk 9) was a follow-on machine to the original Anita C/VIII (Mark 8), the first successfully mass-marketed desktop electronic calculator. The Mk 9 provides the additional feature of chain multiplication to the basic four-function capabilities of the C/VIII. The C/IX was introduced in 1964, around about the time that Sumlock lost its monopoly in the desktop electronic calculator market, due to the introduction of electronic calculators by Friden, Mathatronics, Sharp, and IME.

The Mk 9 utilizes the same cold-cathode Thyraton Valve/Dekatron/Selenium Rectifier technology as the Mark 8. Other than the Mk 10, which was an adaptation of the Mk 9 that provided currency conversion functions, this machine marked the end of Sumlock Comptometer's use of cold-cathode technology, with the future Mk 12 and Mk 11 utilizing transistor technology.

Watch this space for updates on the status of this exhibit as information becomes available.