The Galaga demo crash/freeze bug (I documented it on the KLOV entry years ago). It's a great way to ensure those pesky high scores are reset before playing to ensure my score is the highest. :>
http://www.arcade-museum.com/game_detail.php?game_id=7881
BUG: A bug exists in Galaga and Ms. Pac-Man/Galaga Namco Galaga, some Midway Galaga, Gallag bootleg and Nebulous Bee bootleg - Class of '81 that allows a player to play during the Galaga demo screen and even reset the game. The demos are the same for both Galaga and Ms. Pac-Man/Galaga - Class of '81, and the bug works the same way, but the result is a little different between the two Galagas.
During the Galaga demo, the Galaga character comes down and tries to tractor-beam up the player's ship. As soon as that tractor-beam starts, the player can take control of the ship in the demo. The player has two choices here and this will effect how the game handles this bug:
* If the player allows himself to be captured, the demo will continue as normal and he has the option of controlling the player ship or not. The player can choose whether to save the captured ship, try to complete the level, etc. The demo mode will complete after 30 seconds and the high-score screen will appear.
* If the player takes control of the ship and destroys the Galaga with the tractor beam, he will be able to continue playing until the "normal" demo would have completed. At this point the game will do one of two things depending on whether the person is playing an original Galaga or Ms. Pac-Man/Galaga - Class of '81:
o Galaga: Some of the characters on the screen will freeze while others are still moving and doing what they are suppose to be doing. This will last 15-20 seconds, then the game will go to the high score screen.
o Ms. Pac-Man/Galaga - The game will make a loud buzz sound, blank the screen and then show a diagnostics screen with the version number of the games, a RAM and ROM test, etc. This screen will stay for approximately ten seconds before returning to the high score screen. If someone needs to know the version of software on their boardset, this can be a handy way of finding out without opening the cabinet.