I recently tried the simh emulator, pdp11.

The disk image I used can be found on the internet, and instructions for booting it are here.

Presumably it belonged to Dennis Ritchie, as the username is "dmr".

In the /usr/games folder are about 20 games and amusements for wasting expensive computing resources.

One game is called 'moo'.

I have not been able to find info about this game, but starting it prints:

new game

Every input I have tried results in the game printing 'bad guess.'

Does anyone have experience with this game?

Ritchie is dead, so there's no way to ask him directly.

1 Answer 1


If this is a reimplementation of the same game (it sounds like it based on the prompts), it's an implementation of Mastermind. Try giving it a 4-digit number. It should output a number of "bulls" and "cows", for the number of right digits in the right and wrong places, respectively. For example, if the secret is 1234, the guess 0243 should give you one bull and two cows, while the guess 1235 should give you three bulls and zero cows

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