H alsall (Continued)

and consequently there is consider- able repetition of basic statements. This structure makes it irritating to read in lengthy sessions, but since the book is intended to be used as either a teaching aid or a reference book into which the engineer can dip at will to learn about a particular aspect, this is of little consequence.

The layout of the book will make it quite attractive to management as well as to students and designers. It is well illustrated and the diagrams and tables are well located in the text. It is only occasionally that the explan- ations become heavy going - - this is almost inevitable where the subject matter is very complex.

After a brief description of distri- buted system architectures taking up some nine pages, the book expands into data transmission basics including control circuits, synchron- ization and error detection methods. The jargon of the subject is intro- duced and well explained and then subsequently used in context with a handy glossary at the end to jog the memory. The subjects of error control, flow control and link management are dealt with in some depth before the various types of electrical inter- face are described. The importance of modems and how they contribute in the communication function is given adequate attention.

Having covered the basic features of data transmission, networks are dealt with in a useful fashion. Both wide area and local area networks (LANs) are encompassed and the common as well as the distinguishing characteristics are highlighted. The subject of the ubiquitous ISO seven- layer model has a chapter dedicated to it and for the curious it is possible, for example, to get a sensible under- standing of the purpose and behaviour of any particular layer without having to plough through a lot of intro- ductory material.

The various topologies of LANs are described and the characteristics of the several access methods discussed. The depth is adequate for a general understanding of the subject and the diagrams are quite helpful as are the comments on performance

criteria. It is understandable that, with the speed at which developments are occuring in this area, applications of LANs in industry are not dealt with, nor is the MAP activity promoted by GM mentioned.

The book concludes with two appendices giving some insight into the mysteries of forward error control and data encryption.

In my view, this is a book to be recommended for technical libraries

in industry and managers' book cases alike. It is useful for anyone wishing to learn quickly what data communi- cation is about generally, or alterna- tively to find out a bit more about some particular aspects. It is a bonus that the set problems even allow you to test for what you have learned!

Lionel Thompson Hawker Siddeley Ltd,

Welwyn Garden City, UK

Interactive graphics guide based on IBM PC Chan S Park

'Interactive microcomputer graphics' Addison-Wesley, Wokingham, UK (1985) £36.95 pp xviii + 458

This hardback text is intended for students and practitioners of computer graphics, and uses the IBM PC as a basis for much of the descrip- tion and as a host for the software examples given, which are numerous. This choice should ensure that a large proportion of readers are able to experiment with the techniques described. The book is targetted as an introductory text to computer graphics, or to supplement more advanced programming and manage- ment science courses; the latter is covered by the fourth part of the text.

The hardware and graphics characteristics of the IBM PC are described in part one, at an easily assimilated level. The basic commands available on the PC are described and examples are given of their use. Exercises for the reader, and references, are given at the end of each chapter.

As might be expected, the text is liberally illustrated with clear figures and several full-colour graphics examples.

Part two covers basic mathematics behind 2D and 3D graphics, and hidden line and surface removal. Coordinate systems and 3D rotation are covered in an easy-to-read manner, as are the other topics.

Having covered some basic concepts in parts one and two, part three describes the design of a graphics package, again for the IBM

PC, although it could be ported to other systems without much difficulty. This package handles 2D and 3D plotting, rotation, scaling and trans- lation, data manipulation and input from the keyboard. Complete program source listings in BgSlC are provided and the reader is urged to extend the programs for their own applications.

Part four covers the application of graphics to a particular task, namely management decision making. While this may seem an odd subject for inclusion in a text on interactive microcomputer graphics, the author justifies it on the pretext that it provides a complete discrete example of a real application. I think he is justified in this, although the inclusion is clearly due to a personal interest in this topic.

Multiple regression analysis and economic risk simulation are covered, with software provided.

An appendix covers methods of plotting 3D histograms and stacked bar charts.

One useful feature in the book is a tear-out postcard, offering to dispatch an IBM-compatible floppy disc with all the software in the book for $49.95. There is also a card enabling the reader to take out a licensing agreement- - i t would be interesting to know what proportion of readers take this up.

At £36.95 the book is not cheap. However, its clear illustrations, easy reading style and the material covered make it a worthwhile acquisition for anyone interested in interactive graphics.

Ion Leslie Logica, Swindon, UK

174 microprocessors and microsystems