Apollo 18 for the Apollo Guidance Computer (1966-75)

Written in AGC assembly in about 5 hours for Ludum Dare 59

In an alternate universe where the Apollo 18 mission went ahead, a sophisticated undercover Soviet plot has resulted in the AGC's core rope module being swapped out for one with an malicious program embedded - a version of the code-breaking game Bulls and Cows.

With the craft halfway to the moon the program is activated, and only by using your powers of deduction to solve the puzzle within 12 tries can normal uplink/downlink communication with Houston be resumed, and the mission saved.

To start the game, click any key on the control panel. See below for instructions.

How to play

The code consists of five unique digits. Use the numbered keys to enter your guess.

After each guess, the VERB number will be the number of correct digits exactly in the right position (BULLS)

The NOUN number will be the number of digits that do appear in the code but are in the wrong position (COWS).

The PROG number shows the number of guesses remaining.

Viewing previous guesses

Use the PLUS and MINUS keys to scroll through previous guesses. BULLS and COWS will be shown for the entry in the middle row of digits. The game can be reset by pressing the RSET key.

Clearing guesses

If you change your mind about a guess, use the CLR button to delete the last digit entered.

Winning

If you successfully crack the code it will be displayed in all three rows and various lights will flash. Pressing any key will restart the game.

Losing

If you run out of turns the OPP ERR light will flash and the Apollo 18 mission is doomed, an embarrassing victory for the USSR. The secret code is displayed just to rub it in. The game will restart after a short delay.