Minicomputers, main frames, and distributed systems (Keynote Address)

I propose to divide this lecture into three parts. I would first like to look at the situation as it exists at the present day and to consider the question “When do we use mini-computers and when do we use a main frame? ”. Secondly, I would like to canvass a few ideas, some of them admittedly speculative, on the way in which minicomputers may develop. Thirdly, I would like to consider possible computer systems of the future in which mini-computers form the principal building blocks.