Answer: Tanktics

In 1977 Chris Crawford created a computer game based on the popular table top war games from Avalon Hill called Tanktics: Computer Game of Armored Combat on the Eastern Front. He published the game informally over the next few years and in 1981 Avalon Hill themselves released a boxed set.

The game is most notable for being the first turn-based strategy computer game, a method of game play Crawford had directly translated from table top play. Players would set up the parameters of the game, select the number of tanks they and the opposing force would have. Then, using a system of coordinates (much like those used by play-by-mail chess players) they would compete against the computer using a real board with actual pieces as the program and computers it ran on lacked the computing power to run the game calculations and render a virtual playing board. Although the game was not well received, it did set the stage for future turn-based video games.