Programmable calculators are

calculator An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics. The first solid-state electronic calculator was created in the early 1960s. Pocket-si ...

s that can automatically carry out a sequence of operations under the control of a stored program. Most are

Turing complete Alan Mathison Turing (; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher and theoretical biologist. He was highly influential in the development of theoretical comput ...

, and, as such, are theoretically general-purpose computers. However, their user interfaces and programming environments are specifically tailored to make performing small-scale numerical computations convenient, rather than for general-purpose use. The first programmable calculators such as the IBM CPC used

punched cards A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were wide ...

or other media for program storage. Hand-held electronic calculators store programs on magnetic strips, removable read-only memory cartridges, flash memory, or in battery-backed read/write memory. Since the early 1990s, most of these flexible handheld units belong to the class of

graphing calculator Graphing Calculator may refer to: * Graphing calculators, calculators that are able to display and/or analyze mathematical function graphs * NuCalc, a computer software program able to perform many graphing calculator functions * Grapher, th ...

s. Before the mass-manufacture of inexpensive

dot-matrix A dot matrix is a 2-dimensional patterned Array data structure, array, used to represent characters, symbols and images. Most types of modern technology use dot matrices for display of information, including mobile phones, televisions, and pri ...

LCD A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers to display information. Liquid crystals do not em ...

s, however, programmable calculators usually featured a one-line numeric or

alphanumeric Alphanumericals or alphanumeric characters are any collection of number characters and letters in a certain language. Sometimes such characters may be mistaken one for the other. Merriam-Webster suggests that the term "alphanumeric" may often ...

display. The Big Four manufacturers of programmable calculators are

Casio is a Japanese multinational electronics manufacturing corporation headquartered in Shibuya, Tokyo, Japan. Its products include calculators, mobile phones, digital cameras, electronic musical instruments, and analogue and digital watches. It ...

Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company. It was founded by Bill Hewlett and David Packard in 1939 in a one-car garage in Palo Alto, California ...

, Sharp, and

Texas Instruments Texas Instruments Incorporated (TI) is an American multinational semiconductor company headquartered in Dallas, Texas. It is one of the top 10 semiconductor companies worldwide based on sales volume. The company's focus is on developing analog ...

. All of the above have also made pocket computers in the past, especially Casio and Sharp. Many calculators of this type are monochrome LCD, some are four-color (red or orange, green, blue, and black), or, in the case of some machines at the top of the line as of January 2022 color similar to monitors displaying 16 or 32-bit graphics. As they are used for graphing functions, the screens of these machines are pixel-addressable. Some have a touch screen, buzzers or other sound producers, internal clocks, modems or other connectivity devices including IrDA transceivers, several types of ports for peripherals like printers, and ports for memory cards of a number of types. The wide availability and low cost of

personal computer A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC ...

s including

laptop computer A laptop computer or notebook computer, also known as a laptop or notebook, is a small, portable personal computer (PC). Laptops typically have a Clamshell design, clamshell form factor (design), form factor with a flat-panel computer scree ...

smartphone A smartphone is a mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as multi ...

s and tablets gradually made programmable calculators obsolete for most applications. Many mathematical software packages can be automated and customized through

scripting languages In computing, a script is a relatively short and simple set of instructions that typically automation, automate an otherwise manual process. The act of writing a script is called scripting. A scripting language or script language is a programming ...

and plug-ins in a manner similar to handheld programmable calculators. However, programmable calculators remain popular in secondary and

tertiary education Tertiary education (higher education, or post-secondary education) is the educational level following the completion of secondary education. The World Bank defines tertiary education as including universities, colleges, and vocational schools ...

. Specific calculator models are often required for use in many mathematics courses. Their continued use in education is usually justified by the strictly controllable functionality available. For instance, the calculators do not typically have direct Internet access and so cannot be used for illegal assistance in exams. The remaining programmable calculator manufacturers devote much effort to encourage the continued use of these calculators in high school mathematics.

Earlier devices

Calculator programming

Programmable calculators allow the user to write and store programs in the calculator in order to solve difficult problems or automate an elaborate procedure. Programming capability appears most commonly (although not exclusively) in

s, as the larger screen allows multiple lines of

source code In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer. Since a computer, at base, only ...

to be viewed simultaneously (i.e., without having to

scroll A scroll (from the Old French ''escroe'' or ''escroue''), also known as a roll, is a roll of papyrus, parchment, or paper containing writing. Structure A scroll is usually partitioned into pages, which are sometimes separate sheets of papyru ...

to the next/previous display line). Originally, calculator programming had to be done in the calculator's own command language, but as calculator hackers discovered ways to bypass the main interface of the calculators and write

assembly language In computing, assembly language (alternatively assembler language or symbolic machine code), often referred to simply as assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence bet ...

programs, calculator companies (particularly

) began to support native-mode programming on their calculator hardware, first revealing the hooks used to enable such code to operate, and later explicitly building in facilities to handle such programs directly from the user interface. Many programs written for calculators can be found on the

internet The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...

. Users can download the programs to a

, and then upload them to the calculator using a specialized link cable, infrared wireless link, or through a memory card. Sometimes these programs can also be run through emulators on the PC. Programming these machines can be done on the machine, on the PC side and uploaded as source code, or compiled on the PC side and uploaded as with Flash and some C/C++ implementations. In addition to computer-side language packages such as tigcc, hpgcc, and others, the PC link software available for TI, HP, Casio, and Sharp calculators contain program editors; there are also SDKs, emulators, and other tools for use on the computer side, and other manufacturer and third-party tools like the TI++ editor. Programs, data, and so forth can also be exchanged among similar machines via the same ports on the calculator used for PC connectivity. On-board programming tools which use non-native language implementations include the On-Board C Compiler for fx series Casio calculators and the TI-83 BBC Basic port. One possibility arising from the above is writing interpreters, compilers, and translator programs for additional languages for programming the machines; BBC Basic has already been ported to the TI-83 and -84 series and other onboard languages and programming tools discussed by many include Fortran, awk, Pascal, Rexx, Perl, Common Lisp, Python, tcl, and various Unix shells. Commonly available programs for calculators include everything from

math Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...

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Programming languages

Keystroke programming

In the early days, most programmable calculators used a very simplified programming language, often based either on recording actual keystrokes or

bytecode Bytecode (also called portable code or p-code) is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (normal ...

if the keystrokes were merged. Calculators supporting such programming were

Turing-complete In computability theory, a system of data-manipulation rules (such as a model of computation, a computer's instruction set, a programming language, or a cellular automaton) is said to be Turing-complete or computationally universal if it can be ...

if they supported both conditional statements and indirect addressing of memory. Notable examples of Turing complete calculators were Casio FX-602P series, the HP-41 and the TI-59. Keystroke programming is still used in mid-range calculators like the HP 35s and HP-12C.

BASIC

BASIC Basic or BASIC may refer to: Science and technology * BASIC, a computer programming language * Basic (chemistry), having the properties of a base * Basic access authentication, in HTTP Entertainment * Basic (film), ''Basic'' (film), a 2003 film ...

is a widespread programming language commonly adapted to desktop computers and pocket computers. The most common

languages Language is a structured system of communication that consists of grammar and vocabulary. It is the primary means by which humans convey meaning, both in spoken and signed forms, and may also be conveyed through writing. Human language is ch ...

now used in high range calculators are proprietary

-style dialects as used by

( Casio BASIC or BasicLike) and TI ( TI-BASIC). These BASIC dialects are optimised for calculator use, combining the advantages of BASIC and keystroke programming. They have little in common with mainstream BASIC. The version for the Ti-89 and subsequent is more fully featured, including the full set of string and character manipulation functions and statements in standard Basic. A complete port of

BBC Basic BBC BASIC is an interpreted version of the BASIC programming language. It was developed by Acorn Computers Ltd when they were selected by the BBC to supply the computer for their BBC Literacy Project in 1981. It was originally supplied on ...

to the TI-83 subfamily of calculators is now available. It is installed via a cable or IrDA connection with a computer.

RPL

RPL is a special Forth-like programming language used by

in its high range devices. The first device with RPL calculator was the HP-28C released in 1987. The language PPL was introduced with the HP Prime calculator and is much like Pascal.

Assembly

An assembler integrated into the TI 89 and related calculators was announced and released in 2014. Machine language programming was often discouraged on early calculator models; however, dedicated platform hackers discovered ways to bypass the built-in interpreters on some models and program the calculator directly in

, a technique that was first discovered and utilized on the TI-85 due to a programming flaw in a mode-switching key. By the time the TI-83 came out, TI and HP had realized the need to address the support needs of homebrew programmers, and started to make assembly language libraries and documentation available for prospective developers. Software, particularly games, could now be nearly as fast and as graphical as their

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counterparts, and TI, in particular, would later formalize assembly programming into support for packaged applications for future calculators such as the TI-83 Plus and TI-89; HP included some onboard support for assembler programming on the HP-50g, its then top-of-the-line calculator model. Programs and toolkits to allow on-board assembly-like programming (often Intel 80x86 even if the actual processor in the calculator is something completely different like a Zilog or Motorola chip) are in the beta stage in at least two implementations—the native Basic variant can be enhanced by user-defined functions and procedures as well as assembly and C modules developed on a computer and uploaded to the calculator which allow for writing and running "pseudo assembly" programs just as one would the Basic type ones. Other languages like Rexx, awk, Perl, and some Unix shells can also be implemented in this fashion on many calculators of this type.

Other Languages

The GCC development suite is available for several models of Casio, HP, and TI calculators, meaning that C, C++, Fortran 77, and inline assembly language can be used to develop a program on the computer side and then upload it to the calculator. Projects in development by third parties include on-board and/or computer-side converters, interpreters, code generators, macro assemblers, or compilers for Fortran, other Basic variants, awk, C,

Cobol COBOL (; an acronym for "common business-oriented language") is a compiled English-like computer programming language designed for business use. It is an imperative, procedural, and, since 2002, object-oriented language. COBOL is primarily ...

Rexx Rexx (restructured extended executor) is a high-level programming language developed at IBM by Mike Cowlishaw. Both proprietary and open-source software, open source Rexx interpreter (computing), interpreters exist for a wide range of comput ...

Perl Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language". Perl was developed ...

, Python, Tcl, Pascal,

Delphi Delphi (; ), in legend previously called Pytho (Πυθώ), was an ancient sacred precinct and the seat of Pythia, the major oracle who was consulted about important decisions throughout the ancient Classical antiquity, classical world. The A ...

, and operating system shells like DOS/Win95 batch, OS/2 batch, WinNT/2000 shell, Unix shells, and DCL. Many TI, Casio, Sharp, and HP models have Lua interpreters which are part of the default configuration or can be optionally added. Some calculators run a subset of Fortran 77 called Mini-Fortran; the compiler is on the calculator so connecting to a PC to put programs onto the machine is not needed. The OnCalc C Compiler for the Casio fx-9860 series is now available. The Sharp PC G850V pocket computer has an onboard C compiler in addition to an assembler and a Basic interpreter.

Persistent memory

One important feature of programmable calculators is the availability of some form of persistent memory. Without persistent memory, programs have to be re-entered whenever power is lost, making the device cumbersome. Persistent memory can be internal or on a separate device. Some programmable calculators employ both schemes.

Magnetic card reader / writer

Magnetic card readers were among the first persistent memory options available. The entered programs are stored on magnetic strips. Those were easy to transport, and the reader/writer was compact in size. However, the reader/writer as well as the magnetic strips were quite expensive. The last and most notable devices to use magnetic strips were the

HP-41C The HP-41C series are programmable, expandable, continuous memory handheld RPN calculators made by Hewlett-Packard from 1979 to 1990. The original model, HP-41C, was the first of its kind to offer alphanumeric display capabilities. Later came ...

and TI-59.

Continuous memory

Continuous memory does not lose its content when the calculator is switched off. With continuous memory the user can, for example, change batteries without losing the entered programs.

Cassette tape

Compact cassette The Compact Cassette, also commonly called a cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. Invented by Lou Ottens and his team at the Dutch company ...

s offered a simple, inexpensive alternative to magnetic cards. Usually, an interface module, such as the Casio FA-1, was used to connect the calculator to an ordinary cassette recorder, and digital data were encoded as frequency-shift keyed audio signals. Sharp and

also sold dedicated

micro- ''Micro'' (Greek letter μ, Mu (letter), mu, non-Italic type, italic) is a metric prefix, unit prefix in the metric system denoting a factor of one millionth (10−6). It comes from the Ancient Greek, Greek word (), meaning "small". It is the ...

or mini-cassette recorders that connected directly to the calculator. These set-ups, while being more practical and reliable, were also more expensive.

Semi-continuous memory

As memory demands rose, it became more difficult to create true continuous memory and developers sought alternatives. With semi-continuous memory content was only preserved if specific battery-changing rules were observed. The most common rules were: # A special backup battery would ensure that the memory was not lost while the main batteries were changed. # Battery removal and replacement had to be completed in a relatively short time. For example, with the HP 35s, battery replacement had to be completed in less than 2 minutes after removal. # At least two main batteries were used and could only be changed one at a time.

PC-connection

Programs and data are transferred to a

for storage. The transfer is done by the following connection methods (chronological order of appearance)

RS-232 In telecommunications, RS-232 or Recommended Standard 232 is a standard introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' (''data terminal equipment'') such as a compu ...

, IrDA and

USB Universal Serial Bus (USB) is an industry standard, developed by USB Implementers Forum (USB-IF), for digital data transmission and power delivery between many types of electronics. It specifies the architecture, in particular the physical ...

. This method has the advantage of being very cost-efficient and is usually faster than the cassette interface. These advantages are offset by the need for a personal computer. An early example of a PC connection is the Casio FX-603P in conjunction with the Casio FA-6 interface. In this set-up, transfer was done in

plain text In computing, plain text is a loose term for data (e.g. file contents) that represent only characters of readable material but not its graphical representation nor other objects ( floating-point numbers, images, etc.). It may also include a lim ...

so the program and data could be stored and edited with a standard

text editor A text editor is a type of computer program that edits plain text. An example of such program is "notepad" software (e.g. Windows Notepad). Text editors are provided with operating systems and software development packages, and can be used to c ...

Flash memory

Programmable calculators and pocket computers

Throughout the 1980s and the beginning of the 1990s, programmable calculators stood in competition with pocket computers, with high-end calculators sharing many similarities. For example, both devices types were programmable in unstructured BASIC and with few exceptions featured

QWERTY QWERTY ( ) is a keyboard layout for Latin-script alphabets. The name comes from the order of the first six Computer keyboard keys#Types, keys on the top letter row of the keyboard: . The QWERTY design is based on a layout included in the Sh ...

keyboards. However, there were also some differences: * BASIC-programmable calculators often featured an additional "calculator-like" keyboard and a special calculator mode in which the system behaved like a

scientific calculator A scientific calculator is an Electronics, electronic calculator, either desktop or handheld, designed to perform calculations using basic (addition, subtraction, multiplication, Division (mathematics), division) and advanced (Trigonometric fun ...

. * Pocket computers often offered additional programming languages as option. The Casio PB-2000 for example offered ANSI-C,

, Assembler and

Lisp Lisp (historically LISP, an abbreviation of "list processing") is a family of programming languages with a long history and a distinctive, fully parenthesized Polish notation#Explanation, prefix notation. Originally specified in the late 1950s, ...

. Companies often had both device types in their product portfolio. Casio, for example, sold some BASIC-programmable calculators as part of their "fx-" calculator series (the "FX" was printed in uppercase)The picture of th
FX-700P
an

show the text "programmable calculator" and pocket computer the dedicated "pb-" series while Sharp marketed all BASIC-programmable devices as pocket computers.

Related tools

Some programmable calculators have one or more methods of connecting to a PC for the interchange of data, programs, and software. These methods include IrDA, other wireless, serial ports -including USB or RS-232 via .125 inch or other size audio plugs, etc. Some of the latest programmable calculators contain cellular modems as an additional channel of connectivity. The programmable calculators can in many cases, via these connections, be used with peripherals such as data loggers and interfaces for instruments like thermometers, pH meters, weather instruments of all kinds, light meters, audio probes and microphones, dynamometers, pressure gauges, voltmeters, ammeters, ohm meters, atmospheric electricity measurement apparatus, ion counters, Geiger counters and scintillometers, altimeters, scales, accelerometers, and many others. Some machines can be used with oscilloscopes and their peripherals as well. Others can be configured—for example, collecting bio-feedback data by connecting devices for a pulse, blood pressure, oxygen saturation, galvanic skin resistance, body temperature, and even EKG and EEG probes to a data logger which is then connected to the calculator and, then or later, a PC. The HP programmables and others have an IrDA interface which allows them to interface with the printers specially designed for the calculators, HP's main lines of laser printers, computers, other calculators, and other devices. Also commonly available from many companies are small printers made specifically for calculators which tend to use cash register tape paper, ports and cables for connecting the calculators to a computer and/or another calculator, cassette recorders for recording programs and data, overhead projector displays, and connectors for auxiliary display devices. The earlier programmable calculators, as well as the pocket computers mentioned above, also had such things as video interfaces for televisions and composite monitors, 2½ inch mini floppy disc drives, bar-code readers, and standard

connectivity which provided for other such things as modems, external hard drives and more. The printer selection for the pocket computers was a bit wider as well, including thermal, impact, dot matrix, daisy wheel, 4-colour pen, printers of the type used in simpler printing calculators. Some calculators and pocket computers had external 3½ and 5¼ inch floppy drives, cables for connecting two cassette recorders, cradles containing a printer and/or cassette recorder into which the machine slid, and so on. It is also possible to connect some machines to certain electric typewriters for use as a printer (the typewriters are also able to be connected to PCs for this purpose, and the interface tends to be a standard RS-232 and/or DIN plug), and in some cases to access the typewriter's floppy or micro floppy drives.