Atari Calculator (or Calculator) is a

proprietary software Proprietary software is computer software, software that grants its creator, publisher, or other rightsholder or rightsholder partner a legal monopoly by modern copyright and intellectual property law to exclude the recipient from freely sharing t ...

program developed by Atari, Inc. for

Atari 8-bit computers The Atari 8-bit computers, formally launched as the Atari Home Computer System, are a series of home computers introduced by Atari, Inc., in 1979 with the Atari 400 and Atari 800. The architecture is designed around the 8-bit MOS Technology 650 ...

and published in 1979. It incorporates the functionality of 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 ...

into a

software calculator A software calculator is a calculator that has been implemented as a computer program, rather than as a physical hardware device. They are among the simpler interactive software tools, and, as such, they provide operations for the user to sele ...

. It was written in

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 ...

by American

programmer A programmer, computer programmer or coder is an author of computer source code someone with skill in computer programming. The professional titles Software development, ''software developer'' and Software engineering, ''software engineer' ...

and

game designer Game design is the process of creating and shaping the mechanics, systems, rules, and gameplay of a game. Game design processes apply to board games, card games, dice games, casino games, role-playing games, sports, Wargame (video games), war ga ...

Carol Shaw. The program supports multiple modes, including enabling it to be used as a

programmable calculator Programmable calculators are calculators that can automatically carry out a sequence of operations under the control of a stored computer programming, program. Most are Turing complete, and, as such, are theoretically general-purpose computers. ...

with a then-popular

reverse Polish notation Reverse Polish notation (RPN), also known as reverse Łukasiewicz notation, Polish postfix notation or simply postfix notation, is a mathematical notation in which operators ''follow'' their operands, in contrast to prefix or Polish notation ...

(RPN) input method.

History

In 1977, the ''Calculator''

computer program A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangibl ...

was developed by Carol Shaw at Atari, Inc. In 1979, the screenshot of the ''Atari Calculator'', with the title ATARI CALCULATOR COPYRIGHT 1979 in the main window, was printed in the ''"Touch the future."'' brochure on the screenshots gallery page, featuring the upcoming Atari 800 computer. The UI was colored in light bluish text on a dark blue background. In the same year, the ''"Calculator: Instruction Manual"'' book was printed, and program got product

ID number An identifier is a name that identifies (that is, labels the identity of) either a unique object or a unique ''class'' of objects, where the "object" or class may be an idea, person, physical countable object (or class thereof), or physical nonc ...

CX-8102. On the screenshots of the program, printed in grayscale in the manual, the title in the main window changed to CALCULATOR COPYRIGHT (C) ATARI 1979. In 1981, the ''Calculator'' was marketed in the "''Atari Personal Computer Product Catalog"''. In September 1981, the ''Atari Calculator'' was marketed in ''

Atari Connection ''Atari Connection'' was a magazine for owners of Atari 8-bit computers published by Atari, Inc.'s Computer Division. Editions were quarterly from the spring of 1981 to the summer of 1984 when the company was sold to Jack Tramiel. There was al ...

'' magazine, in the section for new business and professional applications: During 1981—1982, it was distributed in two variants, by Atari, Inc. itself and by the

Atari Program Exchange Atari Program Exchange (APX) was a division of Atari, Inc. that sold software via mail-order for Atari 8-bit computers from 1981 until 1984. Quarterly APX catalogs were sent to all registered Atari 8-bit owners. APX encouraged any programmer, not ...

(APX) department, in the form of boxed

diskette A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...

, together with the Atari DOS 2.0, for the

. In June 1982, the ''"Calculator: Instruction Manual"'' book was printed by the APX, noted with ''"User-Written Software for Atari Computers"'' on the cover, and the program got product ID number APX-20130. In the same year, product CX-8102 was listed in the ''"Atari Home Computer Product Catalog"''. On the screenshot, printed in color in the catalog, the colors of the UI were changed from dark blue to reddish brown, the output line colored in black with gray text, and the input line colored in light bluish colors. After 1982, there was little news about the ''Atari Calculator'', its development, and it was excluded from the listing in the next official catalogs by Atari. On 12 October 2011, Benj Edwards, a tech reporter and historian, published on the ''"Vintage Computing & Gaming"'' site the transcription of the interview with Carol Shaw, who left Atari after 1980. During the interview, there was revealed details about the ''Atari Calculator'' origin and development:

Features

Data sources: the official Atari manuals and catalogs, Carol Shaw's papers, the ''Atari Connection'' magazine, the AtariWiki * Display size: 40×24 characters * Required RAM size: 24 KB * Programming support * Program storage size: 100 memory registers * Stack input size: 42 characters * Memory data storage size: 3072 bytes * Various calculation modes: ** ALG (

algebra Algebra is a branch of mathematics that deals with abstract systems, known as algebraic structures, and the manipulation of expressions within those systems. It is a generalization of arithmetic that introduces variables and algebraic ope ...

ic with

operator precedence In mathematics and computer programming, the order of operations is a collection of rules that reflect conventions about which operations to perform first in order to evaluate a given mathematical expression. These rules are formalized with a ...

) ** ALGN (algebraic without operator precedence) ** RPN (

Reverse Polish Notation Reverse Polish notation (RPN), also known as reverse Łukasiewicz notation, Polish postfix notation or simply postfix notation, is a mathematical notation in which operators ''follow'' their operands, in contrast to prefix or Polish notation ...

) * Various angular modes: DEG, RAD * Various numeric modes: DEC, OCT, HEX * Precision:

Floating point In computing, floating-point arithmetic (FP) is arithmetic on subsets of real numbers formed by a ''significand'' (a signed sequence of a fixed number of digits in some base) multiplied by an integer power of that base. Numbers of this form ...

Integer An integer is the number zero (0), a positive natural number (1, 2, 3, ...), or the negation of a positive natural number (−1, −2, −3, ...). The negations or additive inverses of the positive natural numbers are referred to as negative in ...

Logical operation In logic, a logical connective (also called a logical operator, sentential connective, or sentential operator) is a logical constant. Connectives can be used to connect logical formulas. For instance in the syntax of propositional logic, th ...

s: AND, OR * 145 Functions: Financial,

Statistical Statistics (from German language, German: ', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data. In applying statistics to a s ...

Trigonometric Trigonometry () is a branch of mathematics concerned with relationships between angles and side lengths of triangles. In particular, the trigonometric functions relate the angles of a right triangle with ratios of its side lengths. The field ...

Hyperbolic Hyperbolic may refer to: * of or pertaining to a hyperbola, a type of smooth curve lying in a plane in mathematics ** Hyperbolic geometry, a non-Euclidean geometry ** Hyperbolic functions, analogues of ordinary trigonometric functions, defined u ...

Bit Manipulation Bit manipulation is the act of algorithmically manipulating bits or other pieces of data shorter than a word. Computer programming tasks that require bit manipulation include low-level device control, error detection and error correction, corr ...

Factorial In mathematics, the factorial of a non-negative denoted is the Product (mathematics), product of all positive integers less than or equal The factorial also equals the product of n with the next smaller factorial: \begin n! &= n \times ...

Logarithm In mathematics, the logarithm of a number is the exponent by which another fixed value, the base, must be raised to produce that number. For example, the logarithm of to base is , because is to the rd power: . More generally, if , the ...

, Single- and Double-variable functions, etc. * Polar/Rectangular conversion *

Unit conversion Conversion of units is the conversion of the unit of measurement in which a quantity is expressed, typically through a multiplicative conversion factor that changes the unit without changing the quantity. This is also often loosely taken to incl ...

(temperature, mass, distance, volume, angle, etc.) *

Constants Constant or The Constant may refer to: Mathematics * Constant (mathematics), a non-varying value * Mathematical constant, a special number that arises naturally in mathematics, such as or Other concepts * Control variable or scientific const ...

: π (pi) * Dual-panel view for stack and memory inputs * Tips and Error messages * Various color themes: Brown tones (default), Black and White (positive and negative), Blue/Dark Blue/Green/Pink/Yellow tones * Input/Output * Save/Load * Print out (requires Atari 825 printer to be connected) * Exit to DOS (Atari DOS 2.0 included in diskette distribution)

Alternatives

The ''Atari Calculato''r was not the only RPN calculator for Atari 800, there was also the commercial ''RPN Calculator'' (ID numbers APX-10105 and APX-20105), written in

Atari BASIC Atari BASIC is an interpreter for the BASIC programming language that shipped with Atari 8-bit computers. Unlike most American BASICs of the home computer era, Atari BASIC is not a derivative of Microsoft BASIC and differs in significant way ...

by John Crane, and the ''Atari Rechner Simulation mit UPN'' by MTC (imitating hardware RPN calculator). In the late 1980s, Atari produced a line of hardware

desktop A desktop traditionally refers to: * The surface of a desk (often to distinguish office appliances that fit on a desk, such as photocopiers and printers, from larger equipment covering its own area on the floor) Desktop may refer to various compu ...

and pocket calculators, but none of them had programming support and an RPN input. In October 2014, Norbert Kehrer created free simulators of the

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 ...

RPN calculators (

HP-35 The HP-35 was Hewlett-Packard's first pocket calculator and the world's first ''scientific'' pocket calculator: a calculator with trigonometric and exponential functions. It was introduced in 1972. History In about 1970 HP co-founder Bill He ...

, HP-45, HP-55 and HP-80) for Atari 800XL and Commodore 64.

Legacy

In 2012, the ''Atari Calculator'' was highlighted in an article published in the ''ABBUC Magazin'' (Issue #111), which was published by the German-based, Atari Bit Byter User Club e.V., and the styled ''Atari Calculator'' title was featured on the cover. Cover design and fan art illustrations assisting the article authored by Oliver Rapp. Cover illustration also includes a sign in a lower right corner in a form of mathematical formula to say "

Thank you "Thank you" (often expanded to ''thank you very much'' or ''thanks a lot'', or informally abbreviated to ''thanks'' or alternately as ''many thanks''Geoffrey Leech, ''The Pragmatics of Politeness'' (2014), p. 200.) is a common expression of gr ...

", used by Atari community to honor notable contributors:

\sum_^\infty(Thank\;you\;Carol)_i

Rapp also designed a label for the possible future

ROM cartridge A ROM cartridge, usually referred to in context simply as a cartridge, cart, cassette, or card, is a replaceable part designed to be connected to a consumer electronics device such as a home computer, video game console or, to a lesser extent, ...

release of the ''Atari Calculator'', reserving ID number CXL-4028. On 27—28 April 2013, the ''Atari Calculator'' was displayed at the 14th Vintage Computer Festival Europe (VCFe) in

Munich Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is no ...

, and Vortrag Wassenberg made its presentation. Slides from this presentation were published online. On 22 November 2013, Peter Dell released a ROM cartridge version of the modified original ''Atari Calculator'' with adding startup screen, as a personal gift sent to Carol Shaw: In 2013, Norbert Kehrer ported the original ''Atari Calculator'' to

Commodore 64 The Commodore 64, also known as the C64, is an 8-bit computing, 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in ...

. On 5 November 2014, the ''Atari Calculator'' was highlighted on the 'Inverse ATASCII

Podcast A podcast is a Radio program, program made available in digital format for download over the Internet. Typically, a podcast is an Episode, episodic series of digital audio Computer file, files that users can download to a personal device or str ...

'. The podcast site also published the source of the example program for the ''Atari Calculator,'' newly created

cheat sheet A cheat sheet (also ''cheatsheet'') or crib sheet or job aid is a concise set of notes used for quick reference. Cheat sheets were historically used by students without an instructor or teacher's knowledge to cheat on a test or exam. In the ...

, screenshots of software screen in various modes and an excerpt from the original user manual showing a mistake on instruction illustration.

Colleen Calculator

On 31 August 2016, Kay Savetz, the host of the 'ANTIC podcast', uploaded at the

Internet Archive The Internet Archive is an American 501(c)(3) organization, non-profit organization founded in 1996 by Brewster Kahle that runs a digital library website, archive.org. It provides free access to collections of digitized media including web ...

the scans of the ''Colleen Calculator'' source printouts, an unreleased cartridge version of the ''Atari Calculator'' — obtained from Harry Stewart — which was originally presented by Carol Shaw. In addition, two source printiouts, which included code for

floating-point arithmetic In computing, floating-point arithmetic (FP) is arithmetic on subsets of real numbers formed by a ''significand'' (a Sign (mathematics), signed sequence of a fixed number of digits in some Radix, base) multiplied by an integer power of that ba ...

handling, were scanned and uploaded the ''Atari Calculator'' cartridge specification, handwritten by Shaw, and the official prited user manual for the ''Atari Calculator''. Savetz uploaded it all with a permission from Shaw, and the original printouts Shaw had donated to and now are storing at the

Strong Museum The Strong is an interactive, collections-based educational institution in Rochester, New York, United States, devoted to the study and exploration of play. It carries out this mission through six programmatic arms called "Play Partners": * The ...

, as well as all of the materials related to Atari, she collected during her employment period at the Atari (1978–1980). On 29 June 2017, Shaw was hosted by Savetz on the ''"ANTIC"'' podcast. During the interview, Shaw described more details about the ''Atari Calculator'' and the ''Colleen Calculator'' development. On 4 September 2020, Savetz released on

GitHub GitHub () is a Proprietary software, proprietary developer platform that allows developers to create, store, manage, and share their code. It uses Git to provide distributed version control and GitHub itself provides access control, bug trackin ...

source files of the ''Colleen Calculator'', recovered and reconstructed from scanned printouts. The header in source files includes info on the initial commit date by Shaw: The name of the ''Colleen Calculator'' refers to the codename of Atari 800 — the " Colleen".

Gallery

UI layout from the screenshot printed in 1979: UI layout from the screenshot printed in 1982:

Publications

* (Compressed PDF, 22 MB) * (Original PDF, Gzip'ed, 114 MB) * * * * * * * * * * * * *

References

Atari Calculator
(Atari cartridge by Peter Dell)

(Commodore 64 port by Norbert Kehrer) * Carol Shaw. * John Crane. * Norbert Kehrer

at the ''Museum of HP Calculators'' * MTC. * {{Calculator navbox Atari Atari 8-bit computer software Software calculators Programmable calculators Financial software Mathematical software 1979 software 1982 software