Apple QuickTime movie | 1994-06-26 | 3.4 MB | 320x240 | 15fps | 25 seconds | [MooV/TVOD]
Transcription: A keyboard is a collection of switches. There's one beneath each key. Inside the keyboard, a microprocessor monitors the state of every switch. When you press a key, its switch closes, generating a signal. The keyboard's microprocessor interprets the signal and transmits a code to the Mac. The Mac's system software translates the code into the character that's assigned to it.