Minefield was written for the Compukit UK101 in 1980 by Deric Ellerby.

"The program draws a map on which 20 mines are hidden. You have to move from the South West corner to your based in the North East. To help you, you have a mine detector which looks at all eight squares around you but be warned - the detector 'fails' after 20 moves and then you're on your own!

The game is based on Minefield (1979) by Dowson and the gameplay is similar. For example, visible rocks are replaced with "flooded craters". When you step on a mine there are different messages such as "BOOM!! You're dead!" or "Missile strike!! You're wiped out!". Ellerby also added an "Expert" mode with random missiles that hit you if you move too slowly. The total numbers of mines and craters is 20 but the number of each is random.

The game is a clone but its code is completely new. It was written to use custom ASCII graphics, using PEEK and POKE commands to store the graphics in machine memory. As a result, the code cannot be easily modified for other computers.

The following attributes can be used to map the evolution of Minesweeper. Blue cells are confirmed attributes for official versions of Minefield. Yellow cells are unknown.