earliest days. Though brief, this survey is more than a catalogue of machines; rather it stresses the development of the subject, highlighting features which have been retained in modern implementations. The next two chapters discuss arithmetic and logical operations together with data transfer, before going on to a consideration of the all important topic of microprogramming. These two chapters set the scene very well, and there is frequent reference to specificexamples chosen from modern practice, but essential unity of the subject is stressed throughout. The complementary nature of word length and instructions set is made very apparent. Having dealt with architectural considerations relating to the central processor, the logical next step is to move out to the store. Accordingly the next two chapters deal with addressing techniques and store structure respectively. Once more the treatment is general, stessing architectural features, though specificexamples drawn from modern practice illustrate the situation very well. The final chapter in the main body of the text deals logically enough with input/output devices though the title of the chapter uses the word 'transput'. The final section of the book deals with computers for specialised tasks such as array processors, and also deals with the important subject of fault-tolerant computing. This book is not for the beginner. It is very definitely a second-level text. This said, the book can be recommended with enthusiasm. The author is clearly very knowledgeable and has put much thought into his text. In a very skilful way he has provided a comprehensive treatment of computers and their internal organisation without becoming bogged down by hardware considerations. In this respect he has proved very faithful to his definition of computer architecture. I would suggest, however, that he gives some attention to fig. 1.9for any subsequent edition. This figure gives the strong impression to the superficial reader that the text is to prove a very narrow one. This is certainly not the case. The hardback edition of the book seems rather expensive at £25, but doubtless individual students will be more inclined to buy the paperback version at £12.50.The author is to be congratulated on his new work. M. G. HARTLEY, Department of Electrical Engineering and Electronics, UMIST.
International Journal of Electrical Engineering Education