Programmable calculators are
calculatorAn electronic calculator is a small, portable, usually inexpensive electronic device used to perform the basic operations of arithmetic. Modern calculators are more portable than most computers, though most PDAs are comparable in size to handheld calculators.The first solid-state electronic...
s that can automatically carry out a sequence of operations under control of a stored
programComputer programming is the process of designing, writing, testing, debugging, and maintaining the source code of computer programs. This source code is written in one or more programming languages. The purpose of programming is to create a program that performs specific operations or exhibits a...
, much like a
computerA computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
. The first programmable calculators such as the
IBM CPCThe IBM Card-Programmed Electronic Calculator or CPC was announced by IBM in May 1949. Later that year an improved machine, the CPC-II was also announced.The original CPC Calculator had the following machines interconnected by cables:...
used punched cards or other media for program storage. Hand-held electronic calculators store programs on magnetic strips, removable read-only memory cartridges, or in battery-backed read/write memory.
Since the early 1990s, most of these flexible handheld units belong to the class of
graphing calculatorA graphing calculator typically refers to a class of handheld calculators that are capable of plotting graphs, solving simultaneous equations, and performing numerous other tasks with variables...
s. Before the mass-manufacture of inexpensive dot-matrix LCD displays, however, programmable calculators usually featured a one-line numeric or
alphanumericAlphanumeric is a combination of alphabetic and numeric characters, and is used to describe the collection of Latin letters and Arabic digits or a text constructed from this collection. There are either 36 or 62 alphanumeric characters. The alphanumeric character set consists of the numbers 0 to...
display.
- For earlier devices, see: History of computing hardware
The history of computing hardware is the record of the ongoing effort to make computer hardware faster, cheaper, and capable of storing more data....
Calculator programming
Programmable calculators allow the user to write and store
programsA computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...
in the calculator in order to solve difficult problems or automate an elaborate procedure.
Programming capability appears most commonly (although not exclusively) in
graphing calculatorA graphing calculator typically refers to a class of handheld calculators that are capable of plotting graphs, solving simultaneous equations, and performing numerous other tasks with variables...
s, as the larger screen allows multiple lines of
source codeIn computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...
to be viewed simultaneously (i.e., without having to
scrollIn computer graphics, filmmaking, television production, and other kinetic displays, scrolling is sliding text, images or video across a monitor or display. "Scrolling", as such, does not change the layout of the text or pictures, or but incrementally moves the user's view across what is...
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 languageAn assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
programs, calculator companies (particularly
Texas InstrumentsTexas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
) 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
internetThe Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
. Users can download the programs to a
personal computerA personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
, and then upload them to the calculator using a specialized
link cableA cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry...
, infrared wireless link or through a memory card. Sometimes these programs can also be run through emulators on the PC.
One possibility arising from the above is writing interpreters, compilers, and translator programmes for additional languages for programming the machines; BBC Basic has already been ported to the
TI-83The TI-83 series of graphing calculators is manufactured by Texas Instruments.The original TI-83 is itself an upgraded version of the TI-82. Released in 1996, it is one of the most used graphing calculators for students...
and
-84The TI-84 Plus is a graphing calculator made by Texas Instruments which was released in early 2004. There is no original TI-84, only the TI-84 Plus and TI-84 Plus Silver Edition models. It is an enhanced version of the TI-83 Plus. The key-by-key correspondence is relatively the same, but the 84...
series and other on-board 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/
scienceScience is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...
related problem solvers to
video gamesCalculator gaming is the phenomenon of programming and playing games on programmable calculators, especially graphing calculators. It is largely a pastime of high school and college students, who generally are required to use such powerful calculators in advanced mathematics classes; as a result,...
, as well as so-called
demosThe demoscene is a computer art subculture that specializes in producing demos, which are non-interactive audio-visual presentations that run in real-time on a computer...
. Much of this code is user-created freeware or even
open sourceThe term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
, though commercial software, particularly for educational and science/engineering markets, is also available.
Keystroke programming
In the early days most programmable calculators used a very simplified programming language, often based either on recording actual keystrokes or
bytecodeBytecode, also known as p-code , is a term which has been used to denote various forms of instruction sets designed for efficient execution by a software interpreter as well as being suitable for further compilation into machine code...
if the keystrokes were merged. Calculators supporting such programming were Turing-complete if they supported both conditional statements and indirect addressing of memory. Notable examples of Turing complete calculators were
Casio FX-602P seriesThe FX-601P and FX-602P were programmable calculators, manufactured by CASIO from 1981. It was the successor model to the Casio FX-502P series and was itself succeeded in 1990 by the Casio FX-603P.-Display:...
, the
HP-41The 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...
and the
TI-59The TI-59 was an early programmable calculator, manufactured by Texas Instruments from 1977. It was the successor to the TI SR-52, quadrupling the number of "program steps" of storage, and adding "ROM Program Modules" and a magnetic card reader for external storage...
. Keystroke programming is still used in mid-range calculators like the
HP 35sThe HP 35s Scientific Calculator is, as of 2007, the latest in Hewlett-Packard's long line of non-graphing scientific and programmable calculators...
.
BASIC
BASICBASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code....
is a widespread programming language commonly adapted to desktop computers and pocket computers.
The most common
languagesA programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....
now used in high range calculators are proprietary
BASICBASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code....
-style dialects as used by
CASIOis a multinational electronic devices manufacturing company founded in 1946, with its headquarters in Shibuya, Tokyo, Japan. Casio is best known for its electronic products, such as calculators, audio equipment, PDAs, cameras, musical instruments, and watches...
and
TITexas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
(TI-BASICTI-BASIC is the unofficial name of a BASIC-like language built into Texas Instruments 's graphing calculators, including the TI-83 series, TI-84 Plus series, TI-89 series, TI-92 series , TI-73, and TI-Nspire...
). Those BASIC dialects are optimised for calculator use combining the advantages of BASIC and keystroke programming. Those dialects have little in common with mainstream BASIC .
A complete port of
BBC BasicBBC BASIC is a programming language, developed in 1981 as a native programming language for the MOS Technology 6502 based Acorn BBC Micro home/personal computer, mainly by Sophie Wilson. It is a version of the BASIC programming language adapted for a U.K...
to the TI-83 subfamily of calculators is now available. It is put on the calculator via a cable or IrDA connexion with a computer.
RPL
RPL is a special Forth-like programming language used by Hewlett Packard in its high range devices. The first device with RPL calculator was the HP-28C released in 1987.
Assembler
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
assembly languageAn assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
, a technique that was first discovered and utilized on the
TI-85The TI-85 was a graphing calculator made by Texas Instruments based around the Zilog Z80 microprocessor. Designed in 1992 as TI's second graphing calculator , it has since been replaced by the TI-86, which has also been discontinued....
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
Game BoyThe line is a line of battery-powered handheld game console sold by Nintendo. It is one of the world's best-selling game system lines with a combined 200+ million units sold worldwide....
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 includes some onboard support for assembler programming on the
HP-50gThe HP 49G series are Hewlett-Packard manufactured graphing calculators. They are the successors of the popular HP-48 series.There are four calculators in the 49 series of HP graphing calculators...
, its current top-of-the-line calculator model.
Programmes and toolkits to allow on-board assembly-like programming (often Intel 80*86 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" programmes just as one would the Basic type ones. Other languages like Rexx, awk, Perl, and Windows NT and some Unix shells can also be implemented in this fashion on many calculators of this type.
Other Languages
The
gccThe GNU Compiler Collection is a compiler system produced by the GNU Project supporting various programming languages. GCC is a key component of the GNU toolchain...
development suite is available for several models of HP and TI calculators, meaning that C, C++, Fortran 77, and inline assembly language can be used to develop a programme 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
FortranFortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
, other Basic variants, awk,
CC is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
,
CobolCOBOL is one of the oldest programming languages. Its name is an acronym for COmmon Business-Oriented Language, defining its primary domain in business, finance, and administrative systems for companies and governments....
,
RexxREXX is an interpreted programming language that was developed at IBM. It is a structured high-level programming language that was designed to be both easy to learn and easy to read...
,
PerlPerl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and become widely popular...
,
PythonPython is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...
,
TclTcl is a scripting language created by John Ousterhout. Originally "born out of frustration", according to the author, with programmers devising their own languages intended to be embedded into applications, Tcl gained acceptance on its own...
,
PascalPascal is an influential imperative and procedural programming language, designed in 1968/9 and published in 1970 by Niklaus Wirth as a small and efficient language intended to encourage good programming practices using structured programming and data structuring.A derivative known as Object Pascal...
DelphiDelphi is both an archaeological site and a modern town in Greece on the south-western spur of Mount Parnassus in the valley of Phocis.In Greek mythology, Delphi was the site of the Delphic oracle, the most important oracle in the classical Greek world, and a major site for the worship of the god...
, and operating system shells like DOS/Win95 batch, OS/2 batch, WinNT/2000 shell, Unix shells, and
DCL- Organizations :* Detroit College of Law, now known as Michigan State University College of Law* Data Connection Ltd, see Metaswitch* Disney Cruise Line, a cruise line company * Distillers Company Limited, a producer of spirits...
.
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 within the calculator or as a separate device. Programmable calculators could use more than one technique.
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 and
TI-59The TI-59 was an early programmable calculator, manufactured by Texas Instruments from 1977. It was the successor to the TI SR-52, quadrupling the number of "program steps" of storage, and adding "ROM Program Modules" and a magnetic card reader for external storage...
.
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 CassetteThe Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a magnetic tape sound recording format. It was designed originally for dictation, but improvements in fidelity led the Compact Cassette to supplant the Stereo 8-track cartridge and reel-to-reel...
s offered a simple, inexpensive alternative to magnetic cards. Usually, an interface module, such as the
Casio FA-1The FA-1 Interface was used the FX-502P and FX-602P series of programmable calculator to store programs and data register to Compact Cassette.-External links:* on shows the FA-1 interface....
, was used to connect the calculator to an ordinary cassette recorder and digital data were encoded as
frequency-shift keyedFrequency-shift keying is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a carrier wave. The simplest FSK is binary FSK . BFSK uses a pair of discrete frequencies to transmit binary information. With this scheme, the "1" is called...
audio signals.
Sharpis a Japanese multinational corporation that designs and manufactures electronic products. Headquartered in Abeno-ku, Osaka, Japan, Sharp employs more than 55,580 people worldwide as of June 2011. The company was founded in September 1912 and takes its name from one of its founder's first...
and
Hewlett-PackardHewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
also sold dedicated
micro-A Microcassette is an audio storage medium introduced by Olympus in 1969. It uses the same width of magnetic tape as the Compact Cassette but in a much smaller container. By using thinner tape and half or a quarter the tape speed, microcassettes can offer comparable recording time to the compact...
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 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.
- Batteries had to be changed in a relatively short time. For example with the HP 35s
The HP 35s Scientific Calculator is, as of 2007, the latest in Hewlett-Packard's long line of non-graphing scientific and programmable calculators...
batteries have to be changed in less than 2 minutes.
- 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
Personal computerA personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
for storage. The transfer is done by the following connection methods
(chronological order of appearance) RS-232In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...
,
IrDAThe Infrared Data Association defines physical specifications communications protocol standards for the short-range exchange of data over infrared light, for uses such as personal area networks ....
and
USBUSB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....
. This method has the advantage of being very cost efficient and is usually faster than cassette interface. These advantages are offset by the need of a
Personal computerA personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
. An early example of PC connection is the
Casio FX-603PThe FX-603P was a programmable calculator, manufactured by CASIO from 1990. It was the successor model to the Casio FX-602P.-Display:The FX-603P featured a two line dot matrix display with 16 characters each as main display...
in conjunction with the
Casio FA-6The FA-6 Interface was used with the Casio FX-603P, Casio FX-840P, Casio FX-841P, Casio FX-850P, Casio FX-860P, Casio FX-860Pvc, Casio FX-870P, Casio FX-880P, Casio FX-890P, Casio VX-1, Casio VX-2, Casio VX-3, Casio VX-4, Casio Z-1 and Casio Z-1GR programmable calculator and Pocket Computers.It...
interface. In this set-up transfer was done in
Plain textIn computing, plain text is the contents of an ordinary sequential file readable as textual material without much processing, usually opposed to formatted text....
so the program and data could not only be stored but also
editedEditing is the process of selecting and preparing written, visual, audible, and film media used to convey information through the processes of correction, condensation, organization, and other modifications performed with an intention of producing a correct, consistent, accurate, and complete...
with a standard
Text editorA text editor is a type of program used for editing plain text files.Text editors are often provided with operating systems or software development packages, and can be used to change configuration files and programming language source code....
.
Programmable calculators and pocket computers
Throughout the 80's and the beginning of the 90's programmable calculators stood in competition with
pocket computerA pocket computer is a small calculator-sized handheld programmable computer.This specific category of computers existed primarily in the 1980s. Manufacturers included Casio, Hewlett-Packard, Sharp, Tandy/Radio Shack and many more.The programming language was usually BASIC, but some devices...
s, with high end calculators sharing many similarities. For example both device types were programmable in unstructured BASIC and with few exceptions featured
QWERTYQWERTY is the most common modern-day keyboard layout. The name comes from the first six letters appearing in the topleft letter row of the keyboard, read left to right: Q-W-E-R-T-Y. The QWERTY design is based on a layout created for the Sholes and Glidden typewriter and sold to Remington in the...
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 a type of electronic calculator, usually but not always handheld, designed to calculate problems in science, engineering, and mathematics...
.
- Pocket computers often offered additional programming languages as option. The Casio PB-2000 for example offered ANSI-C
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
, BASICBASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code....
, AssemblerAn assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
and Lisp.
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 and pocket computer the dedicated "pb-" series while
Sharpis a Japanese multinational corporation that designs and manufactures electronic products. Headquartered in Abeno-ku, Osaka, Japan, Sharp employs more than 55,580 people worldwide as of June 2011. The company was founded in September 1912 and takes its name from one of its founder's first...
on marketed all BASIC programmable devices as pocket computer.
See also
- Scientific calculator
A scientific calculator is a type of electronic calculator, usually but not always handheld, designed to calculate problems in science, engineering, and mathematics...
- Graphics calculator
- Pocket computer
A pocket computer is a small calculator-sized handheld programmable computer.This specific category of computers existed primarily in the 1980s. Manufacturers included Casio, Hewlett-Packard, Sharp, Tandy/Radio Shack and many more.The programming language was usually BASIC, but some devices...
- Calculator input methods
There are various ways in which a calculator might interpret key strokes.One can categorize calculators into two main types: 1) single-step or immediate execution calculators and 2) expression or formula calculators....
List of programmable calculators
Casiois a multinational electronic devices manufacturing company founded in 1946, with its headquarters in Shibuya, Tokyo, Japan. Casio is best known for its electronic products, such as calculators, audio equipment, PDAs, cameras, musical instruments, and watches...
:
Casio FX-502P seriesThe FX-501P and FX-502P were programmable calculators, manufactured by CASIO from 1978. They were the predecessors of the Casio FX-601P and Casio FX-602P.-Arithmetic:The FX-502P series use the algebraic logic as was state of the art at the time....
·
Casio FX-602P seriesThe FX-601P and FX-602P were programmable calculators, manufactured by CASIO from 1981. It was the successor model to the Casio FX-502P series and was itself succeeded in 1990 by the Casio FX-603P.-Display:...
·
Casio FX-603PThe FX-603P was a programmable calculator, manufactured by CASIO from 1990. It was the successor model to the Casio FX-602P.-Display:The FX-603P featured a two line dot matrix display with 16 characters each as main display...
·
FX-702PThe FX-702P is a Pocket Computer, manufactured by Casio from 1981 to 1984.-Display:The FX-702P features a single line dot matrix liquid crystal display with 20 characters. A 10-digit mantissa is displayed however internal calculations use a 12-digit mantissa.-Programming:The programming model...
·
FX-850PThe Casio FX-850P is a scientific calculator introduced in 1987 and sold until 1992.- Specifications :* 2 lines with 32 5×7 characters LCD** * 8 KB RAM...
· Casio 9850 series · Casio 9860 series ·
Casio ClassPad 300The Casio ClassPad 300 is a stylus based calculator. HP worked on a pen based calculator called the HP-Xpander, as did Texas Instruments under their , yet both projects were cancelled before they were released to the market. The ClassPad comes with a collection of applications that support...
Hewlett-PackardHewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
:
HP-25The HP-25 was a hand-held programmable scientific/engineering calculator made by Hewlett-Packard between 1975 and 1978. The HP-25 was introduced as a cheaper alternative to the ground-breaking HP-65....
·
HP 35sThe HP 35s Scientific Calculator is, as of 2007, the latest in Hewlett-Packard's long line of non-graphing scientific and programmable calculators...
· HP-41C · HP-48 ·
HP-65The HP-65 was the first magnetic card-programmable handheld calculator. Introduced by Hewlett-Packard in 1974 at an MSRP of $795, it featured nine storage registers and room for 100 keystroke instructions. It also included a magnetic card reader/writer to save and load programs...
Sharpis a Japanese multinational corporation that designs and manufactures electronic products. Headquartered in Abeno-ku, Osaka, Japan, Sharp employs more than 55,580 people worldwide as of June 2011. The company was founded in September 1912 and takes its name from one of its founder's first...
:
PC-1401The Sharp PC-1401 is a small pocket computer manufactured by Sharp. It was introduced in 1983 and represents a combination of scientific calculator and computer with BASIC interpreter...
·
PC-1403The Sharp PC-1403 was a small scientific calculator and pocket computer manufactured by Sharp. It was the successor of the Sharp PC-1401, and had better display, more RAM and better system software.-Technical specifications:...
Texas InstrumentsTexas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
: TI-58 C ·
TI-59The TI-59 was an early programmable calculator, manufactured by Texas Instruments from 1977. It was the successor to the TI SR-52, quadrupling the number of "program steps" of storage, and adding "ROM Program Modules" and a magnetic card reader for external storage...
ElektronikaElectronika is the brand name used for many different electronic products such as calculators, electronic watches, portable games and radios in the Soviet Union and, nowadays, in Russia...
: B3-21 · B3-34 · MK-61 ·
MK-52The Elektronika MK-52 is RPN-programmable calculator which was manufactured in the Soviet Union during the years 1983 to 1992.The functionality of the MK-52 is identical to that of the MK-61, except the MK-52 has an internal non-volatile EEPROM memory module, for permanent data storage, diagnostic...
· MK-85 · MK-90 · MK-92 · MK-98
- MK-152 · MK-161