How it works: the computer

In this book published in 1971 and revised in 1979, they try to explain what a computer is and what it does. The funny part for me is the excessive use of terms like mini-units and micro-units to describe computers that only fill half a room instead of the usual full room :D
Anyway, it's nice vintage stuff that reminds us what long way computers took to become the small-sized, super powered machines we know today.
Enjoy