OXO (software)

OXO (or Noughts and Crosses) is a tic-tac-toe computer game made for the EDSAC computer in 1952. It was written by A.S. (Sandy) Douglas as an illustration for his Ph.D. thesis on human-computer interaction for the University of Cambridge. OXO is the first known (graphical) game to run on a computer.

The player plays against the computer and output was displayed on the computer's 35×16 pixel cathode ray tube. The source code is short, yet plays a perfect game of noughts and crosses. OXO did not have widespread popularity because the EDSAC was a computer unique to Cambridge.

External links