Does anyone know the beginnings, history, and usages of the AS400 computer application system?

Answer 1

"The AS/400 (Application System/400) was first introduced by IBM on June 20th, 1988. The AS/400 is a popular family of mid-sized computer systems which can also be used as multiuser computer systems. By this, we mean that a single computer can interact with more than one user at a time. "

As found here: http://www.texas400.com/tutas400intro.html