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Anita

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Manufacturer: Sumlock Comptometer / Bell-Punch Co., London Type: Anita Mark VIII Year: since 1961 Technology: 11 double triodes 177 cold cathode relay tubes, 1 Dekatron 200 selenium rectifiers, 1(!) transistor Price: DM 4450,-

The Anita is considered to be the first electronic desktop-calculation machine of the world. A prototype of the machine can be found in the London Museum of Science. In its 1/1962 issue the magazine "ELEKTRONIK" published the following newsflash: An electron calculator with the size of a typewriter is now offered by a London company. It can be used for addition, subtraction, multiplication and division. An automatic control equipment is integrated for checking the results. The replies are given in illuminated cyphers in a very short time. And again in a later issue: Some times ago, we could call our readers' attention to the first electronic desktop-calculation machine in the world. ... The improved construction carries now the name Anita Mark C/VIII. Here it's about a ... calculator, working completely silent with an electronic calculation speed, that is in the range of milliseconds. .. It is amazing that at a presentation, after the input of the numeric values, there is no typical rattling sound of electro-mechanic calculation machines but the display quickly and silently shows the result. Previously, the constructor Norman Kitz had contributed to the Brititsh computer of the 1st generation, the Pilot ACE. In the patent specification, the ANITA is even described with a motor step-switch-counter, which is replaced by an electronic ring-counter at the final version. The triode systems work as an oscillator and pulse shaper, the cold cathode relay tube as flip-flops(1 relay tube corresponds to 1 Thyristor in semiconductor technology and saves or counts a bit.). In the thermionic technology, the Dekatron corresponds an 'integrated circuit'. The rectifiers, made of selenium, serve as logic gates and clamping diodes, the transistor is obviously a patch. The frequency is 3kHz. So the ANITA is ten times faster than a fast mechanic calculation machines. Just for the 12-digit accumulator, 120 (about 2/3) of the existing relay tubes are used. That's why the machine only has one electronic register. It's second register, the operand and entry register is the 'complete keyboard', a relic from the times of the mechanic calculation machines. In contrast, a 'classic' mechanic calculation machine owns three to four registers: accumulator, entry register, rotation-counter and possibly multiplicand count register. The ANITA cost as much as a VW-Beetle in 1961.

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