defsystem history

Is there any old timer alive who can tell me about the early history of defsystem? I *suppose* it was inspired by Unix Make — but was it?

When did defsystem appear? It's already quite elaborate in the 1981 edition of the chine nual. But when was it first written? What did lispers use before? Ad hoc load scripts?

What do older Lisp Machine tapes contain? Where can I find those tapes? Does any old MIT tech report tell us anything about defsystem?

Which versions of defsystem did or did not have problems with propagating timestamps?

—♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org It has been my observation that most people get ahead during the time that others waste. — Henry Ford