Precursors to the electronic calculator The first known tools used to aid arithmetic calculations were: bones (used to tally items), pebbles, and
counting boards, and the
abacus, known to have been used by
Sumerians and
Egyptians before 2000 BC. Except for the
Antikythera mechanism (an "out of the time"
astronomical device), development of computing tools arrived near the start of the 17th century: the
geometric-military compass (by
Galileo),
logarithms and
Napier bones (by
Napier), and the
slide rule (by
Edmund Gunter). The
Renaissance saw the invention of the
mechanical calculator by
Wilhelm Schickard in 1623, and later by
Blaise Pascal in 1642. A device that was at times somewhat over-promoted as being able to perform all four
arithmetic operations with minimal human intervention.
Pascal's calculator could add and subtract two numbers directly and thus, if the tedium could be borne, multiply and divide by repetition. Schickard's machine, constructed several decades earlier, used a clever set of mechanised multiplication tables to ease the process of multiplication and division with the adding machine as a means of completing this operation. There is a debate about whether Pascal or Shickard should be credited as the known inventor of a calculating machine due to the differences (like the different aims) of both inventions. Schickard and Pascal were followed by
Gottfried Leibniz who spent forty years designing a four-operation mechanical calculator, the
stepped reckoner, inventing in the process his
leibniz wheel, but who couldn't design a fully operational machine. There were also five unsuccessful attempts to design a calculating clock in the 17th century. The 18th century saw the arrival of some notable improvements, first by
Poleni with the first fully functional calculating clock and four-operation machine, but these machines were almost always
one of a kind.
Luigi Torchi invented the first direct multiplication machine in 1834: this was also the second key-driven machine in the world, following that of
James White (1822). It was not until the 19th century and the
Industrial Revolution that real developments began to occur. Although machines capable of performing all four arithmetic functions existed prior to the 19th century, the refinement of manufacturing and fabrication processes during the eve of the industrial revolution made large scale production of more compact and modern units possible. The
Arithmometer, invented in 1820 as a four-operation mechanical calculator, was released to production in 1851 as an adding machine and became the first commercially successful unit; forty years later, by 1890, about 2,500 arithmometers had been sold plus a few hundreds more from two arithmometer clone makers (Burkhardt, Germany, 1878 and Layton, UK, 1883) and Felt and Tarrant, the only other competitor in true commercial production, had sold 100
comptometers. It wasn't until 1902 that the familiar push-button user interface was developed, with the introduction of the Dalton Adding Machine, developed by James L. Dalton in the
United States. In 1921,
Edith Clarke invented the "Clarke calculator", a simple graph-based calculator for solving line equations involving hyperbolic functions. This allowed electrical engineers to simplify calculations for
inductance and
capacitance in
power transmission lines. The
Curta calculator was developed in 1948 and, although costly, became popular for its portability. This purely mechanical hand-held device could do addition, subtraction, multiplication and division. By the early 1970s electronic pocket calculators ended manufacture of mechanical calculators, although the Curta remains a popular collectable item.
Development of electronic calculators The first
mainframe computers, initially using
vacuum tubes and later
transistors in the logic circuits, appeared in the 1940s and 1950s. Electronic circuits developed for computers also had application to electronic calculators. The
Casio Computer Company, in
Japan, released the Model
14-A calculator in 1957, which was the world's first all-electric (relatively) compact calculator. It did not use electronic logic but was based on
relay technology, and was built into a desk. The
IBM 608 plugboard programmable calculator was IBM's first all-transistor product, released in 1957; this was a console type system, with input and output on punched cards, and replaced the earlier, larger, vacuum-tube
IBM 603. (LED) display from the 1970s (
USSR) In October 1961, the world's first
all-electronic desktop calculator, the British
Bell Punch/Sumlock Comptometer
ANITA (
A New
Inspiration
To
Arithmetic/
Accounting) was announced. This machine used
vacuum tubes, cold-cathode tubes and
Dekatrons in its circuits, with 12 cold-cathode
"Nixie" tubes for its display. Two models were displayed, the Mk VII for continental Europe and the Mk VIII for 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. The ANITA had a full keyboard, similar to mechanical
comptometers of the time, a feature that was unique to it and the later
Sharp CS-10A among electronic calculators. The ANITA weighed roughly due to its large tube system. Bell Punch had been producing key-driven mechanical calculators of the comptometer type under the names "Plus" and "Sumlock", and had realised in the mid-1950s that the future of calculators lay in electronics. They employed the young graduate Norbert Kitz, who had worked on the early British
Pilot ACE computer project, to lead the development. The ANITA sold well since it was the only electronic desktop calculator available, and was silent and quick. The tube technology of the ANITA was superseded in June 1963 by the U.S. manufactured
Friden EC-130, which had an all-transistor design, a stack of four 13-digit numbers displayed on a
cathode ray tube (CRT), and introduced
Reverse Polish Notation (RPN) to the calculator market for a price of $2200, which was about three times the cost of an electromechanical calculator of the time. Like Bell Punch, Friden was a manufacturer of mechanical calculators that had decided that the future lay in electronics. In 1964 more all-transistor electronic calculators were introduced:
Sharp introduced the
CS-10A, which weighed and cost 500,000 yen ($), and
Industria Macchine Elettroniche of Italy introduced the IME 84, to which several extra keyboard and display units could be connected so that several people could make use of it (but apparently not at the same time). The
Victor 3900 was the first to use
integrated circuits in place of individual
transistors, but production problems delayed sales until 1966. from 1967 There followed a series of electronic calculator models from these and other manufacturers, including
Canon,
Mathatronics,
Olivetti,
SCM (Smith-Corona-Marchant),
Sony,
Toshiba, and
Wang. The early calculators used hundreds of
germanium transistors, which were cheaper than
silicon transistors, on multiple circuit boards. Display types used were CRT, cold-cathode
Nixie tubes, and
filament lamps. Memory technology was usually based on the
delay-line memory or the
magnetic-core memory, though the Toshiba "Toscal" BC-1411 appears to have used an early form of
dynamic RAM built from discrete components. Already there was a desire for smaller and less power-hungry machines.
Bulgaria's ELKA 6521, introduced in 1965, was developed by the Central Institute for Calculation Technologies and built at the Elektronika factory in
Sofia. The name derives from
ELektronen KAlkulator, and it weighed around . It is the first calculator in the world which includes the
square root function. Later that same year were released the
ELKA 22 (with a luminescent display) and the ELKA 25, with an built-in printer. Several other models were developed until the first pocket model, the
ELKA 101, was released in 1974. The writing on it was in
Roman script, and it was exported to western countries.
Programmable calculators , an early commercial programmable calculator produced by
Olivetti in 1964 The first desktop
programmable calculators were produced in the mid-1960s. They included the
Mathatronics Mathatron (1964) and the
Olivetti Programma 101 (late 1965) which were solid-state, desktop, printing, floating point, algebraic entry, programmable, stored-program electronic calculators. Both could be programmed by the end user and print out their results. The Programma 101 saw much wider distribution and had the added feature of offline storage of programs via magnetic cards. The
Monroe Epic programmable calculator came on the market in 1967. A large, printing, desk-top unit, with an attached floor-standing logic tower, it could be programmed to perform many computer-like functions. However, the only
branch instruction was an implied unconditional branch (GOTO) at the end of the operation stack, returning the program to its starting instruction. Thus, it was not possible to include any
conditional branch (IF-THEN-ELSE) logic. During this era, the absence of the conditional branch was sometimes used to distinguish a programmable calculator from a computer. The first Soviet programmable desktop calculator
ISKRA 123, powered by the power grid, was released at the start of the 1970s.
1970s to mid-1980s The electronic calculators of the mid-1960s were large and heavy desktop machines due to their use of hundreds of
transistors on several circuit boards with a large power consumption that required an AC power supply. There were great efforts to put the logic required for a calculator into fewer and fewer
integrated circuits (chips) and calculator electronics was one of the leading edges of
semiconductor development. U.S. semiconductor manufacturers led the world in
large scale integration (LSI) semiconductor development, squeezing more and more functions into individual integrated circuits. This led to alliances between Japanese calculator manufacturers and U.S. semiconductor companies:
Canon Inc. with
Texas Instruments,
Hayakawa Electric (later renamed
Sharp Corporation) with North-American Rockwell Microelectronics (later renamed
Rockwell International),
Busicom with
Mostek and
Intel, and
General Instrument with
Sanyo.
Pocket calculators used a crank instead of electronics. The Curta remained the finest pocket calculator available for a quarter of a century. By 1970, a calculator could be made using just a few chips of low power consumption, allowing portable models powered from rechargeable batteries. The first handheld calculator was a 1967 prototype called
Cal Tech, whose development was led by
Jack Kilby at
Texas Instruments in a research project to produce a portable calculator. It could add, multiply, subtract, and divide, and its output device was a paper tape. As a result of the "Cal-Tech" project, Texas Instruments was granted master patents on portable calculators. The first commercially produced portable calculators appeared in Japan in 1970, and were soon marketed around the world. These included the
Sanyo ICC-0081 "Mini Calculator", the
Canon Pocketronic, and the
Sharp QT-8B "micro Compet". The Canon Pocketronic was a development from the "Cal-Tech" project. It had no traditional display; numerical output was on thermal paper tape. Sharp put in great efforts in size and power reduction and introduced in January 1971 the
Sharp EL-8, also marketed as the Facit 1111, which was close to being a pocket calculator. It weighed 1.59 pounds (721 grams), had a
vacuum fluorescent display, rechargeable
NiCad batteries, and initially sold for US$395. However,
integrated circuit development efforts culminated in early 1971 with the introduction of the first "calculator on a chip", the MK6010 by
Mostek, followed by Texas Instruments later in the year. Although these early hand-held calculators were very costly, these advances in electronics, together with developments in display technology (such as the
vacuum fluorescent display,
LED, and
LCD), led within a few years to the cheap pocket calculator available to all. In 1971,
Pico Electronics and
General Instrument also introduced their first collaboration in ICs, a full single chip calculator IC for the Monroe Royal Digital III calculator. Pico was a spinout by five GI design engineers whose vision was to create single chip calculator ICs. Pico and GI went on to have significant success in the burgeoning handheld calculator market. The first truly pocket-sized electronic calculator was the
Busicom LE-120A "HANDY", which was marketed early in 1971. Made in Japan, this was also the first calculator to use an LED display, the first hand-held calculator to use a single integrated circuit (then proclaimed as a "calculator on a chip"), the
Mostek MK6010, and the first electronic calculator to run off replaceable batteries. Using four AA-size cells the LE-120A measures . The first European-made pocket-sized calculator, DB 800 was made in May 1971 by
Digitron in
Buje,
Croatia (former
Yugoslavia) with four functions and an eight-digit display and special characters for a negative number and a warning that the calculation has too many digits to display. The first American-made pocket-sized calculator, the Bowmar 901B (popularly termed
The Bowmar Brain), measuring , came out in the autumn of 1971, with four functions and an eight-digit red LED display, for , while in August 1972 the four-function
Sinclair Executive became the first slimline pocket calculator measuring and weighing . It retailed for around £79 ( at the time). By the end of the decade, similar calculators were priced less than £5 ($). Following protracted development over the course of two years including a botched partnership with Texas Instruments,
Eldorado Electrodata released five pocket calculators in 1972. One called the Touch Magic was "no bigger than a pack of cigarettes" according to
Administrative Management. The first
Soviet Union made pocket-sized calculator, the
Elektronika B3-04 was developed by the end of 1973 and sold at the start of 1974. One of the first low-cost calculators was the
Sinclair Cambridge, launched in August 1973. It retailed for £29.95 ($), or £5 ($) less in kit form, and later models included some scientific functions. The Sinclair calculators were successful because they were far cheaper than the competition; however, their design led to slow and less accurate computations of
transcendental functions (maximum three decimal places of accuracy).
Scientific pocket calculators Meanwhile,
Hewlett-Packard (HP) had been developing a pocket calculator. Launched in early 1972, it was unlike the other basic four-function pocket calculators then available in that it was the first pocket calculator with
scientific functions that could replace a
slide rule. The $395
HP-35, along with nearly all later HP engineering calculators, uses
reverse Polish notation (RPN), also called postfix notation. A calculation like "8 plus 5" is, using RPN, performed by pressing , , , and ; instead of the algebraic
infix notation: , , , . It had 35 buttons and was based on Mostek Mk6020 chip. The first Soviet
scientific pocket-sized calculator the "B3-18" was completed by the end of 1975. In 1973,
Texas Instruments (TI) introduced the
SR-10, (
SR signifying
slide rule) an
algebraic entry pocket calculator using
scientific notation for $150. Shortly after the
SR-11 featured an added key for entering
pi (π). It was followed the next year by the
SR-50 which added log and trig functions to compete with the HP-35, and in 1977 the mass-marketed
TI-30 line which is still produced. In 1978, a new company,
Calculated Industries arose which focused on specialized markets. Their first calculator, the Loan Arranger (1978) was a pocket calculator marketed to the Real Estate industry with preprogrammed functions to simplify the process of calculating payments and future values. In 1985, CI launched a calculator for the construction industry called the Construction Master which came preprogrammed with common construction calculations (such as angles, stairs, roofing math, pitch, rise, run, and feet-inch fraction conversions). This would be the first in a line of construction related calculators. File:Calculator Adler 81S.jpg|Adler 81S pocket calculator with
vacuum fluorescent display (VFD) from the mid-1970s. File:Casio cm602.jpg|The Casio CM-602 Mini electronic calculator provided basic functions in the 1970s. File:SinclairExecutive-01.jpg|The 1972
Sinclair Executive pocket calculator. File:Hp-35 1972.jpg|The
HP-35, the world's first scientific pocket calculator by Hewlett Packard (1972). File:Canon Pocketronic.jpg|Canon Pocketronic calculator prints output using paper tape (1971).
Programmable pocket calculators The first programmable pocket calculator was the
HP-65, in 1974; it had a capacity of 100 instructions, and could store and retrieve programs with a built-in magnetic card reader. Two years later the
HP-25C introduced
continuous memory, i.e., programs and data were retained in
CMOS memory during power-off. In 1979, HP released the first
alphanumeric, programmable,
expandable calculator, the
HP-41C. It could be expanded with
random-access memory (RAM, for memory) and
read-only memory (ROM, for software) modules, and peripherals like
bar code readers,
microcassette and
floppy disk drives, paper-roll
thermal printers, and miscellaneous communication interfaces (
RS-232,
HP-IL,
HP-IB). , the first programmable pocket calculator (1974) The first Soviet pocket battery-powered programmable calculator,
Elektronika B3-21, was developed by the end of 1976 and released at the start of 1977. The successor of B3-21, the
Elektronika B3-34 wasn't backward compatible with B3-21, even if it kept the
reverse Polish notation (RPN). Thus B3-34 defined a new command set, which later was used in a series of later programmable Soviet calculators. Despite very limited abilities (98 bytes of instruction memory and about 19 stack and addressable registers), people managed to write all kinds of programs for them, including
adventure games and libraries of calculus-related functions for engineers. Hundreds, perhaps thousands, of programs were written for these machines, from practical scientific and business software, which were used in real-life offices and labs, to fun games for children. The
Elektronika MK-52 calculator (using the extended B3-34 command set, and featuring internal
EEPROM memory for storing programs and external interface for EEPROM cards and other periphery) was used in Soviet spacecraft program (for
Soyuz TM-7 flight) as a backup of the board computer. This series of calculators was also noted for a large number of highly counter-intuitive mysterious undocumented features, somewhat similar to "
synthetic programming" of the American
HP-41, which were exploited by applying normal arithmetic operations to error messages, jumping to nonexistent addresses and other methods. A number of respected monthly publications, including the popular science magazine
Nauka i Zhizn (
Наука и жизнь,
Science and Life), featured special columns, dedicated to optimization methods for calculator programmers and updates on undocumented features for hackers, which grew into a whole esoteric science with many branches, named "
yeggogology" ("еггогология"). The error messages on those calculators appear as a Russian word "YEGGOG" ("ЕГГОГ") which, unsurprisingly, is translated to "Error". A similar hacker culture in the US revolved around the
HP-41, which was also noted for a large number of undocumented features and was much more powerful than
B3-34.
Technical improvements Through the 1970s the hand-held electronic calculator underwent rapid development. The red LED and blue/green
vacuum fluorescent displays consumed a lot of power and the calculators either had a short battery life (often measured in hours, so rechargeable
nickel-cadmium batteries were common) or were large so that they could take larger, higher capacity batteries. In the early 1970s
liquid-crystal displays (LCDs) were in their infancy and there was a great deal of concern that they only had a short operating lifetime. Busicom introduced the Busicom
LE-120A "HANDY" calculator, the first pocket-sized calculator and the first with an LED display, and announced the Busicom
LC with LCD. However, there were problems with this display and the calculator never went on sale. The first successful calculators with LCDs were manufactured by
Rockwell International and sold from 1972 by other companies under such names as: Dataking
LC-800, Harden
DT/12, Ibico
086, Lloyds
40, Lloyds
100, Prismatic
500 (a.k.a.
P500), Rapid Data
Rapidman 1208LC. The LCDs were an early form using the
Dynamic Scattering Mode DSM with the numbers appearing as bright against a dark background. To present a high-contrast display these models illuminated the LCD using a filament lamp and solid plastic light guide, which negated the low power consumption of the display. These models appear to have been sold only for a year or two. A more successful series of calculators using a reflective DSM-LCD was launched in 1972 by
Sharp Inc with the Sharp
EL-805, which was a slim pocket calculator. This, and another few similar models, used Sharp's
Calculator On Substrate (COS) technology. An extension of one glass plate needed for the liquid crystal display was used as a substrate to mount the needed chips based on a new hybrid technology. The COS technology may have been too costly since it was only used in a few models before Sharp reverted to conventional circuit boards. (1987) In the mid-1970s the first calculators appeared with field-effect,
twisted nematic (TN) LCDs with dark numerals against a grey background, though the early ones often had a yellow filter over them to cut out damaging
ultraviolet rays. The advantage of LCDs is that they are passive light modulators reflecting light, which require much less power than light-emitting displays such as LEDs or VFDs. This led the way to the first credit-card-sized calculators, such as the
Casio Mini Card LC-78 of 1978, which could run for months of normal use on button cells. There were also improvements to the electronics inside the calculators. All of the logic functions of a calculator had been squeezed into the first "calculator on a chip"
integrated circuits (ICs) in 1971, but this was leading edge technology of the time and yields were low and costs were high. Many calculators continued to use two or more ICs, especially the scientific and the programmable ones, into the late 1970s. The power consumption of the integrated circuits was also reduced, especially with the introduction of
CMOS technology. Appearing in the Sharp "EL-801" in 1972, the
transistors in the logic cells of CMOS ICs only used any appreciable power when they changed state. The LED and
VFD displays often required added driver transistors or ICs, whereas the LCDs were more amenable to being driven directly by the calculator IC itself. With this low power consumption came the possibility of using
solar cells as the power source, realised around 1978 by calculators such as the Royal
Solar 1, Sharp
EL-8026, and Teal
Photon. File:CasioFX20-inside.jpg|The interior of a Casio fx-20 scientific calculator from the mid-1970s, using a VFD. The processor integrated circuit (IC) is made by
NEC (marked μPD978C). Discrete electronic components like
capacitors and
resistors and the IC are mounted on a
printed circuit board (PCB). This calculator uses a battery pack as a power source. File:Sharp el-323 ic 1ae.jpg|The processor chip (integrated circuit package) inside a 1980s Sharp pocket calculator, marked SC6762 1•H. An LCD is directly under the chip. This was a PCB-less design. No discrete components are used. The battery compartment at the top can hold two
button cells. File:Casio fx-992VB interior both aa1.JPG|Inside a Casio scientific calculator from the mid-1990s, showing the processor chip (small square; top-middle; left), keypad contacts, right (with matching contacts on the left), the back of the LCD (top; marked 4L102E), battery compartment, and other components. The solar cell assembly is under the chip. File:Citizen se-733 int 1ac.jpg|The interior of a newer () pocket calculator. It uses a button battery in combination with a solar cell. The processor is a "Chip on Board" type, covered with dark
epoxy.
Mass-market phase At the start of the 1970s, hand-held electronic calculators were very costly, at two or three weeks' wages, and so were a luxury item. The high price was due to their construction requiring many mechanical and electronic components which were costly to produce, and production runs that were too small to exploit
economies of scale. Many firms saw that there were good profits to be made in the calculator business with the margin on such high prices. However, the cost of calculators fell as components and their production methods improved, and the effect of economies of scale was felt. By 1976, the cost of the cheapest four-function pocket calculator had dropped to a few dollars, about 1/20 of the cost five years before. The results of this were that the pocket calculator was affordable, and that it was now difficult for the manufacturers to make a profit from calculators, leading to many firms dropping out of the business or closing. The firms that survived making calculators tended to be those with high outputs of higher quality calculators, or producing high-specification scientific and programmable calculators.
Mid-1980s to present was a programmable RPN-style calculator that accepted extension modules; it was manufactured in the
Soviet Union from 1985 to 1992 The first calculator capable of symbolic computing was the
HP-28C, released in 1987. It could, for example, solve quadratic equations symbolically. The first
graphing calculator was the
Casio fx-7000G released in 1985. The two leading manufacturers, HP and TI, released increasingly feature-laden calculators during the 1980s and 1990s. At the turn of the millennium, the line between a graphing calculator and a
handheld computer was not always clear, as some very advanced calculators such as the
TI-89, the
Voyage 200 and
HP-49G could
differentiate and
integrate functions, solve
differential equations, run
word processing and
PIM software, and connect by wire or
IR to other calculators/computers. The
HP 12c financial calculator is still produced. It was introduced in 1981 and is still being made with few changes. The HP 12c featured the
reverse Polish notation mode of data entry. In 2003 several new models were released, including an improved version of the HP 12c, the "HP 12c platinum edition" which added more memory, more built-in functions, and the addition of the algebraic mode of data entry.
Calculated Industries competed with the HP 12c in the mortgage and real estate markets by differentiating the key labeling; changing the "I", "PV", "FV" to easier labeling terms such as "Int", "Term", "Pmt", and not using the
reverse Polish notation. However, CI's more successful calculators involved a line of construction calculators, which evolved and expanded in the 1990s to present. According to Mark Bollman, a mathematics and calculator historian and associate professor of mathematics at Albion College, the "Construction Master is the first in a long and profitable line of CI construction calculators" which carried them through the 1980s, 1990s, and to the present. ==Use in education==