OXO was a computer game written for the EDSAC computer in 1952, an implementation of the game known as Noughts and Crosses in the UK, or tic-tac-toe in the United States. It was written by Alexander S. Douglas as an illustration for his Ph.D. thesis on human-computer interaction for the University of Cambridge. OXO was the first digital graphical game to run on a computer.[1]
The simulation was played using a rotary telephone controller. OXO is often listed as the first computer game.[citation needed]
In OXO the player played against the computer, and output was displayed on the computer's 35×16 pixel cathode ray tube. The source code was short, yet it played a perfect game of noughts and crosses. OXO did not have widespread popularity because the EDSAC was a computer unique to Cambridge.
