That is so cool - takes me back to my days at BMEWS.
I was an operator and the active computer had one bit referenced and piped to a speaker at the console. Now the computer was running many programs, but the main part cycled on a 2 1/2 second cycle. We would listen to this 'melody', not really bothering us, and if the computer started to have problems the tone would change slightly and we were alerted to problems before the alarm circuits were tripped.
