My Performa has a strange quirk. It seems to be morally opposed to giving system errors with text in them. Either that, or it's just too lazy for words.
These errors pop up when I leave the Performa running unattended for a certain period of time. Also, like most system errors, they sometimes appear for no apparent reason. The crashes don't interrupt normal use of the computer - it crashes about as often as most other computers do when they're actively being used.
The Performa has been in my family since before I was born, and nearly all of the bomb errors I've seen have looked like th