was a video game
designed by Windmill System
to run on IBM PC
compatibles using Intel 8088
8Mhz machine on CGA
4-color displays back in 1983. It used to run tolerably fast on IBM PC-AT
16Mhz chips. However, by the time 80386
PC comes about Digger
no longer runs at a playable speed.
Now, it has been lovingly reversed-engineered by Andrew Jenner to run on modern Pentium machines, and in Windows 9x. You can get the software for free at http://www.digger.org/. This is a recommended retro game.