''OXO'' is a

video game A video game or computer game is an electronic game that involves interaction with a user interface or input device (such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device) to generate visual fe ...

developed by A S Douglas in 1952 which simulates a game of noughts and crosses (tic-tac-toe). It was one of the first games developed in the

early history of video games The history of video games spans a period of time between the invention of the first electronic games and today, covering many inventions and developments. Video game, Video gaming reached mainstream popularity in the 1970s and 1980s, when arcad ...

. Douglas programmed the game as part of a thesis on human-computer interaction at the

University of Cambridge The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209, the University of Cambridge is the List of oldest universities in continuous operation, wo ...

. The program was written for the

Electronic Delay Storage Automatic Calculator The Electronic Delay Storage Automatic Calculator (EDSAC) was an early British computer. Inspired by John von Neumann's seminal ''First Draft of a Report on the EDVAC'', the machine was constructed by Maurice Wilkes and his team at the Universi ...

(EDSAC). EDSAC was one of the first

stored-program computer A stored-program computer is a computer that stores program instructions in electronically, electromagnetically, or optically accessible memory. This contrasts with systems that stored the program instructions with plugboards or similar mechani ...

s, with memory that could be read from or written to, and had three small

cathode-ray tube A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms on an oscilloscope, a ...

screens to display the state of the memory; Douglas re-purposed one screen to demonstrate portraying other information to the user, such as the state of a noughts and crosses game. After the game served its purpose, it was discarded on the original hardware but later successfully reconstructed. ''OXO'', along with a

checkers Checkers (American English), also known as draughts (; English in the Commonwealth of Nations, Commonwealth English), is a group of Abstract strategy game, strategy board games for two players which involve forward movements of uniform game ...

game by

Christopher Strachey Christopher S. Strachey (; 16 November 1916 – 18 May 1975) was a British computer scientist. He was one of the founders of denotational semantics, and a pioneer in programming language design and computer time-sharing.F. J. Corbató, et al., T ...

completed around the same time, is one of the earliest known games to display visuals on an electronic screen. Under some definitions, it thus may qualify as the first video game, though other definitions exclude it due to its lack of moving or real-time updating graphics.

History

The

(EDSAC) mainframe computer was built in the

's Mathematical Laboratory between 1946 and 6 May 1949, when it ran its first program, and remained in use until 11 July 1958. The EDSAC was one of the first

s, with memory that could be read from or written to, and filled an entire room; it included three 35×16 dot matrix

s (CRTs) to graphically display the state of the computer's memory. As a part of a thesis on human-computer interaction, Sandy Douglas, a doctoral candidate in mathematics at the university, used one of these screens to portray other information to the user; he chose to do so via displaying the current state of a game. Douglas used the EDSAC to simulate a game of noughts and crosses, and display the state of the game on the screen. Like other early video games, after serving Douglas's purpose, the game was discarded. Douglas did not give the game a name beyond "noughts and crosses"; the name ''OXO'' first appeared as the name of the simulation file created by computer historian

Martin Campbell-Kelly Martin Campbell-Kelly FCBS FLSW (born 1960) is an Emeritus Professor at the University of Warwick who has specialised in the history of computing. Education Campell-Kelly was educated at Sunderland Polytechnic where he was awarded a PhD in ...

while creating a simulation of the EDSAC several decades later. Around the same time that ''OXO'' was completed,

expanded a

program he had originally written in 1951 and ported it to the

Ferranti Mark 1 The Ferranti Mark 1, also known as the Manchester Electronic Computer in its sales literature, and thus sometimes called the Manchester Ferranti, was produced by British electrical engineering firm Ferranti Ltd. It was the world's first commer ...

, which showed the state of the game on a CRT display. ''OXO'' and Strachey's checkers program are the earliest known games to display visuals on an electronic screen, though it is unclear which of the two games was displayed first. As it ran on a computing device and used a graphical display, ''OXO'' is considered under some definitions to be a contender for the first video game, though under others it does not due to its lack of moving graphics or graphics which update continuously.

Interaction

Each game was played by one user against an

artificially intelligent Artificial intelligence (AI) is the capability of computer, computational systems to perform tasks typically associated with human intelligence, such as learning, reasoning, problem-solving, perception, and decision-making. It is a field of re ...

opponent, which could play a "perfect" game. The player entered their input using a rotary telephone controller, selecting which of the nine squares on the board they wished to move next. Their move would appear on the screen, and then the computer's move would follow; the game display only updated when the game state changed. ''OXO'' was not available to the general public and could only be played in the University of Cambridge's Mathematical Laboratory by special permission, as the EDSAC could not be moved, and both the computer and the game were only intended for academic research purposes.

References

External links

The Edsac Simulator — An emulator of the EDSAC developed by Martin Campbell-Kelly that includes ''OXO''
{{Tic-Tac-Toe 1952 video games Early history of video games History of computing in the United Kingdom Puzzle video games Tic-tac-toe University of Cambridge Computer Laboratory Video games developed in the United Kingdom Single-player video games