It's hard to beieve we've had PC's for 30 years already! Is that 30 years from the invention of the PC or 30 years since it has been available to the public? I know that the military and other organizations had PC's long before they were widely available to the rest of us.

Thirty years ago I didn't know PC's existed. In fact, I didn't know how to turn one on until about 5 years ago!