Data General AOS/VS Easter Egg - Magic in AOS

This is not so much an easter egg as it was a debugging tool. The CLI (command line interpreter) had this undocumented command in it. It was a unique command in that it was handled prior to being sent to the command parser. This provided a mechanism to test the command parser itself. Early CLI versions had expanded functionality in this command- The xyzzy command would accept switches and/or arguments and respond accordingly. After debugging was complete, xyzzy was left in for sentimental reasons. Virtually all of its functionality was removed, thus when invoking this command, "nothing happens." No doubt the developers had this in mind from the start. Incidentally, the word "xyzzy" is pronounced "magic", and "magic" was the Data General code name for AOS/VS.

When DG came out with CLI32, a completely rewritten 32-bit version of the original 16-bit AOS CLI, the first thing that everyone did is type 'xyzzy'. The response on the 32-bit version: 'Twice as much happens'.