Notes on the Electronic Calculator

Since infancy, I have had a great fascination with calculators, in fact just about as much as with flashlights. This is because they were always around me growing up. Before my dad became a special education teacher, he was a bank executive so therefore he always had a calculator until his career change. My mom has taught high school math since 1980 and she has always EDCed a scientific calculator or two. I had EDCed a calculator on and off since the age of eight and then permanently since the age of twenty-five. Though both of my parents are teachers, I am not. I am more or less of an amateur tradesman, especially in the trades of electrical and computer repair. Because of this, I greatly realize the need to EDC a calculator, though not for the same reason as my parents. For a while, I have been also EDCing a composition book on which I take notes on subjects that I consider important to me. On October 2nd and 3rd of 2018, I did some research on electronic calculators and took notes into my composition book. I am transcribing these notes for others to read.

Without further ado, here are my notes on electronic calculators:

Wikipedia is the source I cite as that is where the bulk of this information comes from.

The first solid state electronic calculator was created in the early 1960s.

Pocket-sized models came avaailable in the 1970s after the first microprocessor, the Intel 4004 was invented.

By the end of the 1970s, basic calculators were affordable to most and became common in schools.

In 1986 ~41% of the world’s general purpose hardware capacity was represented by calculators. As of 2007, it is only 0.05%.

Processor Components:

The Scanning/Polling Unit scans the keypad waiting to receive an electrical signal when a key is pressed.

The X and Y registers are where numbers are temporarily stored during calculations. All numbers go into the X register first, the number in the X register is displayed.

The function for the calculation is stored in the Flag Register until the calculator needs it.

The Permanent or Read Only Memory or ROM is the instructions for built-in functions that are permanently stored and cannot be deleted.

The User or the Random Access Memory or RAM is where numbers can be stored by the user and contents can be changed or erased by the user.

The Arithmetic Logic Unit or ALU executes all arithmetic and logic instructions and produces results in binary code.

The Binary Decoder Unit converts the binary results into decimal numbers which are shown on the display unit.

The clock rate of the processor chip refers to the frequency of which the Central Processing Unit is running. It indicates the processor’s speed and is measured in clock cycles per second and expressed in the unit of Hertz. Basic calculations can vary between a few hundred Hertz to the KiloHertz range.

The first devices used to aid in arithmetic calculations were bones, pebbles, counting boards and the Abacus which was used in ancient Egypt and Sumeria before 2000 BC.

Computing tools started to arrive in the 17th Century with inventions such as the Geometric Military Compass, made by Galileo.

Logarithms and Napier’s bones were invented by Scottish mathematician John Napier of Merchiston (1550-April 4, 1617.)

The slide rule was invented by English and Welsh clergyman, mathematician and astronomer Edmund Gunter (1581-December 10, 1626.)

In 1642, the mechanical calculator was invented by German professor and minister Wilheim Schickard (April 22, 1592-October 24, 1635) several decades before the device invented by French mathematician, physicist and writer Blaise Paschal (June 19, 1623-August 19, 1662.) Schikard’s device used a well-thought set of mechanized multiplication tables to quicken the process of multiplication and division. Paschal’s calculator could add and subtract two numbers directly.

German polymath Gottfried Leibinz (July 1, 1646-November 14, 1716) spent four decades attempting to design a four operation mechanical calculator he called “The Step Reckoner. he was not successful but in the process, he invented “The Leibinz Wheel.”

At that point my medication kicked in and I went to bed, then resumed taking notes on October 3, 2018.

There were five other unsuccessful attempts to design a calculating clock in the 17th Century.

The first successful calculating clock was invented in the 18th Century by Marquess physicist, mathematician and antiquarian Giovanni Poleni (1683-November 1761.)

Assumed Italian inventor Luigi Torchi (1812-?) invented the first direct multiplication machine and the second key-driven machine in the world, following James White’s invention in 1822.

Real developments began during the Industrial Revolution of the 19th Century. This made large scale production of devices that could perform all four functions of arithmetic.

The Arithmometer was invented in 1820 and put into production in 1851. It became the first commercially sold unit and by 1890, 2,500 units had been sold. There were even clone units from Burkhardt, Germany, in 1878 and Layton, UK, in 1883.

In 1902, American James Dalton invented The Dalton Adding Machine with the first push-button interface.

In 1921, American Electrical Engineer Edith Clarke (February 10, 1883-October 29, 1959), the first female professor of Electrical Engineering at UTA invented the “Clarke Calculator” which was a simple graph-based calculator for solving line equations that involved hyperbolic functions. This device gave electrical engineers the ability to simply calculate inductance and capacitance in power transmission lines.

In 1948, Austrian engineer Curt Herzstark (July 26, 1902-October 27, 1988) invented the pocket portable calculator which was called the “Curta.”

Casio released the Model 14-A in 1957. It was the world’s first all-electric compact calculator.

In October of 1961, British Bell Punch/Sumlock Comptometer ANITA, which is an acronym for “A New Inspiration To Arithmetic/Accounting” was announced. It used cold cathode tubes and Dekatrons in its circuits in addition to 12 cold cathode Nixie tubes. There were two models displayed: the Mk VII was for Continental Europe and the MK VIII was for the UK and the rest of the world.

Tubes began to be phased out in 1963 when the American-made Friden EC-130 was built of an all transistor design. It featured a stack of four thirteen digit numbers and a five-inch cathode ray tube. It also introduced Reverse Polish Notation. This machine sold for $2,200.

In 1964 Sharp introduced the CS-10A. It weighed 25 kilograms or 55 pounds and cost 500,000 yen or $4,457.52.

Italian company Industria Machine Electroniche also introduced the IME-84 with several peripherals so several users could make use of it (but not simultaneously.)

Several manufacturers followed including Canon, Mathatronics, Olivetti, Toshiba, Smith Carona Marchant, and Wang. These calculators used Germanium as opposed to Silicon for their transistors. Displays were either Cathode Ray Tube or cold cathode Nixie tubes and filament lamps. Memory was either delayed line memory or magnetic core memory. However, the Toshiba “Toscal” BC-1411 possibly had an early form of Dynamic Random Access Memory.

In late 1965, the Olivetti Programma 101 was released. It could read and write stored programs on magnetic memory cards and display the results on its built-in printer. Memory was achieved with an acoustic delay line and could be partitioned between program steps, constants and data registers. It could be considered the first commercially made personal computer and won many industrial design awards.

Also in 1965 the Bulgarian made ELKA 6521 was released. The name is derived from a portmanteau of ELektronen KAlkulator. It weighed 8 kilograms or 18 pounds. It was the first calculator to feature a square root function. Later in 1965 the ELKA 25 with a built-in printer was introduced. The ELKA 101 was released in 1974 and was ELKA’s first pocket model. It featured Roman script (I guess as opposed to Slavic)since it was exported to Western Countries.

In 1967, the Monroe Epic was put on the market. It was a large printing desktop model with an attached floor standing logic tower. It could be programmed to carry out many computer-like functions. Unfortunately, the only branch instruction was an implied unconditional branch (GO TO) at the end of the operation stack, which returned the program to its starting instruction. Therefore it was impossible to include any conditional branch ie (IF-THEN-ELSE) logic.

During this time period, the absence of a conditional branch sometimes determined the difference between a programmable calculator and a computer.

Also in 1967, Texas Instruments American electrical engineer Jack Kilby (November 8, 1923-June 20, 2005) led the production of the first prototype of a handheld calculator, the “Cal Tech.” It could perform the four basic operations and printed the results on paper tape.

In 1970 a calculator could be produced with just a few low power chips and be powered by rechargeable batteries. Also in 1970, the first portable calculators appeared in Japan and were sold around the world. Models included the Sanyo ICC-0081 Mini Calculator, the Canon “Pocketronic” and the Sharp QT-8B “micro compet.”

Desiring to reduce power consumption, Sharp introduced the EL-8 which was also marketed as the Facit IIII. it was close to being a pocket model and weight 1.59 pounds or 721 grams, had a vacuum fluorescent display, rechargeable NiCad batteries and sold for $395.

In early 1971, the first “Calculator on a chip” the MK6010 was made by Mostek. Also in 1971, Pico Electronics and General Instrument introduced the chipset for the Monroe Royal Digital III calculator.

The Busicom LE-120A “HANDY” was the first truly pocket-sized calculator. It was the first to feature an LED display, first to use a single integrated circuit and the first to run on primary batteries. It measured 4.9 inches by 2.8 inches by 0.9 inches (124 millimeters by 71 millimeters by 23 millimeters.)

The DB800 was made in 1971 in Buje, Croatia, and was the first European made pocket calculator.

The Bowmar 901B was the first American made pocket-sized calculator which measured 5.2 inches by 3.0 inches by 1.5 inches (132 millimeters by 76 millimeters by 38 millimeters) and was put on the market in Autumn of 1971. It featured the four basic functions, a red LED display and sold for $240.

Then in 1972, the first slimline pocket calculator was released. It was the Sinclair Executive. Measuring 5.4 inches by 2.2 inches by 0.35 inches (137.2 millimeters by 55.9 millimeters by 8.9 millimeters), it sold for 79 Pounds.

The first pocket-sized Soviet-made calculator was the Elektronika B3-04 was developed in 1973 and put on the market in 1974.

In 1973, the Sinclair Cambridge was launched. It sold for 29.95 Pounds or $38.40. Because of their lower price, Sinclair units were popular but they were slower and sometimes produced inaccurate results with transcendental functions.

The first Soviet-made, pocket-sized scientific model B3-18 was completed by the end of 1975.

Texas Instruments introduced the SR-10 (SR stands for “Slide Rule.”) It was an algebraic entry-level pocket calculator using scientific notation and sold for $150. Afterward, the SR-11 was released and had a dedicated key for the Pi constant. The following year, the SR-50 was released and added the trigonometric and logarithmic functions. It was a competitor model to the Hewlett Packard HP-35.

In 1976, the Texas Instruments TI-30 was launched and descendants of it are still in production.

In 1978, Calculated Industries made special purpose calculators such as the “Loan Arranger” which was marketed to Real Estate professionals. In 1985 they launched the “Construction Master” which was marketed to the building trades.

Programmable calculators such as the Mathatronics and Casio AL-100 were very heavy and costly.

The Hewlett Packard HP-65 came out in 1974 and had a capacity of 100 instructions and could store and retrieve programs in a built-in magnetic card reader. The HP-25 introduced continuous memory which stored data and programs in a CMOS. The HP-41C was released in 1979 and could be expanded with Random Access Memory and Read Only Memory. It could also be connected to bar code readers, microcassette and floppy drives as well as printers and communication interfaces such as the RS-232, HP-IL, and HP-IB.

The ISKRA123 was Soviet-made, grid powered and released in the early 1970s. The Elektronika B3-21 was developed at the end of 1976 and put on the market in early 1977. Its successor, the B3-34 was widely used and hundreds of thousands of games and program were written for it. The Elektronika MK-52 was used in the Soviet Space Program.

The Hewlett Packard HP-28C was released in 1987 and was the first calculator capable of symbolic programming.

The Casio fx-7000G was released in 1985 as the world’s first graphing calculator.

In 1981, the Hewlett Packard 12-C was the first financial calculator…


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