Editing Sumlock ANITA calculator

{{Short description|1961 all-electronic desktop calculator}}

{{More citations needed|date=September 2018}}

{{Use dmy dates|date=October 2017}}
[[File:AnitaMk8-01.jpg|right|thumb|275px|ANITA Mk VIII.]]

The '''ANITA''' Mark VII and '''ANITA''' Mark VIII [[calculator]]s were launched simultaneously in late 1961 as the world's first all-[[Electronics|electronic]] desktop [[calculator]]s.<ref name="officemag1961"/><ref name="BuromaschinenMechaniker1961"/> Designed and built by the [[Bell Punch|Bell Punch Co]]. in [[United Kingdom|Britain]], and marketed through its [[Sumlock Comptometer]] division, they used [[vacuum tube]]s and [[cold-cathode]] switching tubes in their [[logic circuit]]s and [[nixie tube]]s for their numerical displays.<ref>Keith Houston. ''Empire of the Sum: The rise and reign of the pocket calculator'' (2023)</ref>

They were the first of a series of desktop and hand-held electronic calculators that the company was to develop and sell under the ANITA name into the mid-1970s.

== History of ANITA calculators ==
The acronym ''ANITA'' was officially proclaimed to be derived from, variously, ''A New Inspiration to Arithmetic'', or ''A New Inspiration to Accounting'', though there have been rumours that this was also the name of the designer's wife.

The Bell Punch Company (named after its first product, a ticket punch with a bell used by [[tram]] and [[bus]] conductors) had been producing a very successful range of key-driven mechanical [[calculator]]s of the [[Comptometer]] type under the names "Plus" and "Sumlock", since the 1930s. In 1956 the young graduate Norbert Kitz (also known as Norman Kitz), who had worked on the early British [[Pilot ACE]] computer project, had a chance meeting with some of the directors of Control Systems Ltd.,<ref name="Kitz">Kitz N: "Met de Geestelijke Vader van ANITA" (translation:"With the mental father of ANITA"), ''Anita's Wereld'' (an advertising paper for ANITA calculators), Amsterdam, April 1963, p3.</ref> of which the Bell Punch Company was then a subsidiary. Some years earlier, while researching the introduction to his dissertation, he was looking at the mechanical calculators in the [[Science Museum (London)|Science Museum]], [[London]], United Kingdom, and had realised that the future of calculators lay in electronics. Unfortunately, the major mechanical calculator manufacturers were far away in the US and Germany, and Kitz's idea lay dormant until he raised it at that meeting. The directors were very forward looking and were impressed by Kitz and his idea. They decided to open an Electronics Development Department, and took on Kitz as the leader of a project to develop an electronic version of the company's mechanical calculators. To help confidentiality the project was given the code-name ANITA.

Since the company had production lines capable of manufacturing precision mechanical parts by the thousand, the first experimental models were mechanical and electronic hybrids. However, these proved impractical and a purely electronic design was pursued.

Being the first in the field there were several major technical areas that required considerable development:<ref name="Kitz"/>
* The electronic circuits for the four arithmetic functions: add, subtract, multiply, divide.
* An electronic circuit which could store numbers being used in the calculation without taking up a lot of space and requiring a lot of power.
* A suitable keyboard to enter the numbers of a calculation. This had to have a long life and also give good electrical reliability.
* A suitable numerical output to display the results.

[[File:AnitaPrototype1.jpg|left|thumb|The prototype ANITA electronic calculator of 1958, with some of the covers removed, on display in the [[Science Museum (London)|Science Museum]], [[London]].]]

However, the main constraint was to be the cost of the calculator. The cheapest electronic computer then cost approximately £50,000 [[GBP]] but to be competitive with mechanical calculators the target selling price of the electronic calculator was in the range £350 to £400.

The first all-electronic prototype was demonstrated to the board of the company in December 1958.<ref name="Kitz"/> This prototype was later donated by the company to the [[Science Museum (London)|Science Museum]] in [[London]], where Kitz had originally had the idea for the electronic calculator. It has been on display surrounded by the mechanical calculators that it was to make obsolete. There then followed several years of great effort in finding electronic and mechanical components suitable for production, testing them for suitability, and where necessary producing them within the company or finding someone to produce them to their specification.

The great culmination of all the effort was revealed in October 1961, when the world's first ''all-electronic desktop'' calculators were launched. These were the ANITA Mk VIII at the ''Business Efficiency Exhibition'' in [[London]], [[United Kingdom]], from 2 to 11 October, and the ANITA Mk VII at the ''Hamburg Business Equipment Fair'', [[Germany]], from 10 to 13 October.<ref name="officemag1961">"Simple and Silent", ''Office Magazine'', Dec. 1961, p1244</ref><ref name="BuromaschinenMechaniker1961">"'Anita' der erste tragbare elektonische Rechenautomat" [trans: "the first portable electronic computer"], ''Buromaschinen Mechaniker'', Nov. 1961, p207</ref>

[[File:AnitaMk8-02.jpg|left|thumb|Close up of an ANITA Mk VIII.]]
[[File:AnitaMk8Inside1.jpg|left|thumb|Inside an operating ANITA Mk VIII.]]

Since [[transistor]] technology was still in its infancy, these machines used [[vacuum tube]]s, cold-cathode tubes, and [[Dekatron]]s in their circuits, and cold-cathode [[Nixie tube]]s for their displays. This technology was fairly robust and cost effective;<ref name = "MacDougall">MacDougall, M.A., "Using the cold-cathode tube: part 1", ''Electronics'', Mar. 22, 1965, p78</ref> the Dekatron counter tube being the equivalent of an [[integrated circuit]] [[counter (digital)|counter]]. The ANITA Mk VII was marketed in continental Europe while the ANITA Mk VIII was marketed in Britain and the rest of the world, both for delivery from early 1962. The Mk VII was a slightly earlier design with a more complicated mode of multiplication and was soon dropped in favour of the simpler Mark VIII version. The logic circuits, although digital, were based on decimal notation rather than binary; as Kitz himself stated at a symposium "no binary stunts here!".<ref name="Symposium">Kitz N: "Cold Cathode Trigger Tubes for Computing Applications", ''Symposium on "Cold Cathode Tubes and their Applications"'', University of Cambridge, March 1964, pIII/7/1 to III/7/9</ref> Similar to the [[Comptometer]] calculating machines of the time, the ANITA had a full keyboard, a feature that was unique to it and the later [[Sharp Corporation|Sharp]] CS-10A among electronic calculators. Being silent and very quick in operation, and the only electronic desktop calculator available, the ANITA sold well, reaching nearly 10,000 units per year by 1964.<ref name="Symposium"/>

1961 was a doubly notable year for the Bell Punch Company since it then also amalgamated its calculator division with the British operation of [[Comptometer Corporation]] of Chicago, US (formerly the Felt & Tarrant Manufacturing Co.), to form Sumlock Comptometer Ltd. It thus gained the right to use the name "''[[Comptometer]]''" and even manufactured mechanical calculators to be sold by Comptometer Corporation in the US.<ref>Darby E: "It all adds up: The growth of Victor Comptometer Corporation", Victor Comptometer Corporation, 1968</ref>

Development and some manufacture of the ANITA calculators took place at the Bell Punch Company's headquarters in [[Uxbridge]], about 15 miles (24&nbsp;km) to the west of [[London]], [[United Kingdom]].  However, the main production facility was in [[Portsmouth]], on the south coast, where the company expanded the original site there, opened in 1952 to produce mechanical calculator parts, by acquiring additional buildings.  For production of the thousands of circuit boards the company invested in the then new technology of [[wave soldering]].

With the appearance of the ANITA calculators, other calculator manufacturers pressed on with designs for electronic models.  In late 1963 and 1964 competition finally arrived with the launch of all-[[transistor]] models such as the Friden ''EC-130'', IME ''84'', and Sharp ''CS-10A''.  Initially the competing electronic calculators were no cheaper nor smaller than the ANITA, but Bell Punch responded by opening a new research and development building on its Uxbridge site, and electronics research was increased for the calculators and the other Bell Punch products.

The ANITA name continued to be used for the series of models of desktop calculators that followed, which gradually moved to [[transistor]] and [[integrated circuit]] technology, and from the early 1970s, the hand-held models.

In 1966 the calculator manufacturing operation of the Bell Punch Company was formed into a separate company, called Sumlock-Anita Electronics, and continued to manufacture both the mechanical and electronic calculators, still marketed by its Sumlock Comptometer division.

There was a major development in 1973 when the Sumlock Anita Electronics division was bought by its main supplier of [[integrated circuits]], [[Rockwell International]] of the US.<ref>Valery, N: "Shopping around for a calculator", ''New Scientist'', 1973, p549-551</ref>  The remainder of the Bell Punch Co. continued manufacturing and selling its other products, such as taximeters.

In 1976 Rockwell decided to exit the calculator market, by which time cheap calculators had markedly reduced the profitability of the industry.  Sumlock Anita Electronics was closed down and the ANITA name was sold to a marketing company and soon disappeared.<ref>"Rockwell closes Anita factory", ''Computer Weekly'', 22 January 1976</ref>  The rest of the Bell Punch Company, which was completely independent of Rockwell, continued in business to about 1986 when it was closed down.

== Further information about the early ANITA calculators ==
* The first of the ANITA models was called the Mk VII (i.e. Mark VII) because the development of the mechanism of the Sumlock mechanical calculators made by the company had already gone through design numbers Mk I to Mk VI. So the next number in the series was used for the first electronic design.
* The moulded plastic casing of the first ANITA calculators was particularly complicated for the time, and required development of new techniques by the moulding company.<ref>"Intricate Moulding in ABS Plastic", ''Engineering'', 30 Mar. 1962, p435</ref> Originally moulded in [[Acrylonitrile butadiene styrene|ABS]] the material was later changed to [[polycarbonate]] for improved fire resistance.
* Operators converting from mechanical machines to the new electronic ANITA calculators often complained initially that the key stroke was too light and did not give the feel of the mechanical machine. Also, they missed the noise of the mechanism which indicated that the calculation was taking place and went quiet when the calculation was completed.
* An article of 1965 on cold cathode tubes from Mullard Ltd. (a British manufacturer of these devices, which also produced a prototype calculator using them) gives an insight into why they were used in these calculators at the time - ''"... They are an accountant's dream; a typical modern [cold cathode] tube has a life expectancy several thousand times better than the conventional thermionic tube, although they employ voltages of the same order. They are much cheaper than either semiconductor devices or vacuum tubes; they do not require costly materials with a high degree of purity in their manufacture, nor do they need transformers or cooling systems to operate. The tubes require no warm-up period and they can take severe overload."''<ref name="MacDougall"/>

== Known ANITA calculator models ==
=== Desktop models ===
* ANITA ''Mk VII'' - 1961, cold-cathode tube logic, full keyboard, 12-digit [[Nixie tube|''"Nixie"'']]-type tube display.
* ANITA ''Mk VIII'' (aka ''Mk 8'') - 1961, cold-cathode tube logic, full keyboard, 12-digit [[Nixie tube|''"Nixie"'']]-type tube display.
* ANITA ''Mk 9'' - 1964, cold-cathode tube logic, full keyboard, 12-digit [[Nixie tube|''"Nixie"'']]-type tube display, capable of chain multiplication.
* ANITA ''Mk 10'' - 1965, cold-cathode tube logic, full keyboard, 12-digit [[Nixie tube|''"Nixie"'']]-type tube display, can display in Decimal or the pre-decimalisation [[Pound sterling]] Currency mode.
* ANITA ''Mk 11'' - 1969, hybrid cold-cathode tube and transistor logic, 10-key keyboard, 9-digit [[Nixie tube|''"Nixie"'']]-type tube display, low cost.
* ANITA ''Mk12'' - 1966, hybrid cold-cathode tube and transistor logic, 10-key keyboard, 12-digit [[Nixie tube|''"Nixie"'']]-type tube display.

[[File:Anita1011-1.jpg|right|thumb|ANITA 1011]]

* ANITA ''410P'' - details not known.
* ANITA ''500P'' - details not known.
* ANITA ''1000'' - 1969, IC & transistor logic, 10-key keyboard, 10-digit [[Nixie tube|''"Nixie"'']]-type tube display.
* ANITA ''1010'' - 1969, IC & transistor logic, 10-key keyboard, 10-digit [[Nixie tube|''"Nixie"'']]-type tube display, %.
* ANITA ''1011'' - 1969, IC & transistor logic, 10-key keyboard, 10-digit [[Nixie tube|''"Nixie"'']]-type tube display, memory.
* ANITA ''1011P'' - 1971, IC & transistor logic, 10-key keyboard, printer, memory.
* ANITA ''1020'' - 1970, IC & transistor logic, 10-key keyboard, 10-digit [[Nixie tube|''"Nixie"'']]-type tube display, square root.
* ANITA ''1021'' - 1970, IC & transistor logic, 10-key keyboard, memory, 10-digit [[Nixie tube|''"Nixie"'']]-type tube display, memory, square root.

[[File:Anita1011LSI-01.jpg|right|thumb|ANITA 1011 LSI]]

* ANITA ''1000 LSI'' - 1971, IC logic, 10-key keyboard, 10-digit [[Nixie tube|''"Nixie"'']]-type tube display.
* ANITA ''1000B LSI'' - c. 1971, IC logic, 10-key keyboard, 10-digit [[Nixie tube|''"Nixie"'']]-type tube display, AC & rechargeable batteries.
* ANITA ''1011 LSI'' - 1971, IC logic, 10-key keyboard, 10-digit [[Nixie tube|''"Nixie"'']]-type tube display, %, memory.
* ANITA ''1011B LSI'' - 1971, IC logic, 10-key keyboard, 10-digit [[Nixie tube|''"Nixie"'']]-type tube display, %, memory, AC & rechargeable batteries.
* ANITA ''1011P'' - c. 1971, IC logic (?), 10-key keyboard, printer, %, memory.
* ANITA ''1021 LSI'' - details unknown.
* ANITA ''1041'' - details unknown.
* ANITA ''1211 LSI'' (aka ''1211D'') - IC logic, 10-key keyboard, 12-digit "Panaplex" display, %.
* ANITA ''1211P'' - 1973, IC logic (?), 10-key keyboard, printer.
* ANITA ''1212D'' - 1972, IC logic (?), 10-key keyboard, 10-digit [[Nixie tube|''"Nixie"'']]-type tube display, 2 memories.
* ANITA ''1212P'' - date unknown, IC logic (?), 10-key keyboard, printer.
* ANITA ''1233D'' - 1972, IC logic (?), 10-key keyboard, multiple memories.
* ANITA ''1233P'' - 1973, IC logic (?), 10-key keyboard, printer, multiple memories.
* Rockwell-ANITA ''811 SL'' - 1974, IC logic, 10-key keyboard, 8-digit "Panaplex II" display, %, memory.
* Rockwell-ANITA ''1041'' - 1975, IC logic, 10-key keyboard, 16-digit "Panaplex II" (10 digits mantissa, 2 digits exponent), scientific functions, memory.
* Rockwell-ANITA ''1211'' - date unknown, IC logic, 10-key keyboard, 12-digit "Panaplex II" display, %, memory.
* Rockwell-ANITA ''1211 SL'' - 1974, IC logic, 10-key keyboard, 12-digit "Panaplex II" display, %, memory.
* Rockwell-ANITA ''1211P'' - 1973, IC logic, 10-key keyboard, printer.
* Rockwell-ANITA ''1216'' - c. 1973, IC logic, 10-key keyboard, 12-digit "Panaplex"-type display, %, memory, made in the US,
* Rockwell-ANITA ''1432'' - details unknown.

=== Hand-held models ===
[[File:Anita811-01.jpg|right|100px|thumb|ANITA 811]]
* ANITA ''810'' - date unknown, 8-digit red [[LED]] display.
* ANITA ''811'' - 1972, 8-digit red [[LED]] display, %, memory. The first Anita hand-held calculator.
* ANITA ''831'' - date unknown, 8-digit red [[LED]] display, %, memory, square root.
* ANITA ''841'' - date unknown, 8-digit red [[LED]] display, Scientific.
* ANITA ''851'' - date unknown, 8-digit red [[LED]] display, metric conversion.
* ANITA ''861'' - date unknown, 8-digit red [[LED]] display, Financial.
* ANITA ''8041'' - date unknown, 8-digit green [[Vacuum fluorescent display]], scientific, similar to ANITA 841, made in Yugoslavia for Fi-cord International, Didsbury, Manchester, England.
* Triumph-Adler ''81'' - c1972, similar to the ANITA ''811''. Made by Sumlock-Anita for [[Triumph-Adler]] and sold under both the ''"Triumph"'' and ''"Adler"'' labels.
* Rockwell-ANITA ''102'' - date unknown, 8-digit red [[LED]] display, assembled in Mexico.
* Rockwell-ANITA ''201'' - date unknown, 8-digit red [[LED]] display, %, memory, assembled in Mexico.
* Rockwell-ANITA ''202/SR'' - date unknown, 8-digit green [[Vacuum fluorescent display]], scientific, assembled in Mexico (?).

Sumlock-Anita Electronics also assembled in Britain some of the Rockwell hand-held calculators, including Rockwell models ''8R'', ''10R'', ''18R'', ''20R'', ''21R'', ''30R'', ''31R''.

The "Panaplex" is a gas-discharge display, using 7 segments to represent each number, within a thin glass "sandwich". The numerals glow amber.

This list of calculator models may not be complete.

==Patents==
* GB patent 868,753 – ''Improvements in or relating to Calculating Machines'' – Norbert Kitz, Robert Milburn, Christopher Webb: Bell Punch Company Ltd., 1961 (first application 6 September 1956, filed 6 September 1957), - Electronically controlled key operated office desk type calculating machine capable of addition, subtraction, multiplication, and division.
* {{US patent|3280315}} - ''Key controlled decimal electronic calculating machine'' – Norbert Kitz: Bell Punch Company Ltd., 1966 (filed 29 December 1961), - Electromechanical and "space discharge type" electronic calculating machine capable of addition, subtraction, multiplication, and division.

== References ==
{{Reflist}}

== External links ==
* [http://www.vintagecalculators.com/html/sumlock_anita.html Summary of the history of the ANITA calculator]
* [http://www.anita-calculators.info/ Extensive history of the ANITA calculator]

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[[Category:Electronic calculators]]
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