This book covers two distinct topics: (1) a history of serial data transmission techniques, with some digressions into cpu hardware and serial channel programming, and (2) a detailed introduction to the IBM 3270 series data stream protocols. It is entirely concerned with text terminals and also covers communication protocols. The author makes a brief mention of the psychology of human-computer interaction.

The second part of the book contains many interesting general ideas about data streams. It is worth reading on that count. Unfortunately, these ideas are not clearly identified, but instead are lost in a mass of detail about 3270 protocols. There are rather too many diagrams. For examples, the reader is asked to inspect the flow chart on p. 171. For such a small flow chart, it could hardly have been more confusing. It must have been produced by a flow chart generator program with no thought for the reader. Some good artwork should have been used for all the diagrams in place of the low quality, computer-produced printing. For instance, downwards arrows in diagrams in the book are made with a vertical bar and an ill-fitting upper-case “V”.

The network functions standards OSI and SNA are both mentioned very briefly and quite separately. There has been discussion in Britain recently about the manner in which IBM’s SNA could be integrated with the OSI standard favored by British Telecom. The book does not help with understanding the discussion.

This book may be particularly useful to people wishing to emulate 3270 protocols on other types of terminals, as well as for people wishing to write host computer programs to support 3270 terminals. It could be useful as a student text in a situation where IBM details are presented in preference to more abstract and general concepts.