The idea behind this book, say the authors, is that “mainframe users can have the speed and storage range of the large systems and yet work through a friendly and appealing user interface.” In the preface, they state that the book guides its readers through the step-by-step development of an online text display and management system for mainframes, particularly those from IBM.

Books on hypertext tend to be hyperactively enthusiastic about the subject without saying much about it, and unfortunately this one falls into the same trap. The book is truly useful if you want a broad overview of online text management: Part 1 defines online systems and mainframe hardware and software requirements, Part 2 describes the history and development of online systems, Part 3 talks about presenting text on the screen, Part 4 goes into document formats, and Part 5 touches lightly on text access and search strategies.

However, the book is not useful if you want actual algorithms or detailed comparisons of the few online text-management facilities available on mainframes. Appendix C, “Creating a Prototype On-line Text Environment,” describes in only three pages the authors’ struggle to create a prototype hypertext system. After reading it, I felt sure that they worked very hard on the book and the prototype. It is too bad that they could not make it possible for readers to look at the prototype over a modem or from a demo diskette. Another irony of the information age is that we have plenty of distribution channels for books, magazines, and dry goods, but hardly any for electronic information.