This book covers the topic of mainframe computers, the room-sized units that dominated and defined computing in the 1950's and 1960's. The coverage is of efforts mainly in the United States, although significant efforts in the U.K., Germany, and other countries were also involved.
How did we get where we are? Initially computers were big, unique, heavy mainframes with a dedicated priesthood of programmers and system engineers to keep them running. They were enshrined in specially air conditioned rooms with raised floors and access control. They ran one job at a time, taking punched cards as input, and producing reams of wide green-striped paper output. Data were collected on reels of magnetic tape, or large trays of punched cards. Access to these very expensive resources was necessarily limited. Computing was hard, but the advantages were obvious – we could collect and crunch data like never before, and compute things that would have worn out our slide rules.