Using the Unix systemRichard GauthierPrentice-Hall International, 1982, 297pp., £14.20ISBN: 8359-8164-9

Traditionally, operating systems were written specificallyfor a particular brand of hardware and, for large main-frames, were generated to include only those portionsneeded to control a given configuration. The developmentof portable systems, such as Unix, means that a machineand its operating system may be considered, and evenpurchased, separately. This has placed a greater emphasison the availablity of software facilities and has increasedthe interest in ease of use of the total system and its userfriendliness. One therefore needs to know, before thesoftware is purchased and the manuals become available,exactly what to expect. Recourse to journals and technicalpublications is one answer, but a text written specificallyfor prospective users is probably more appropriate.

'Using the Unix system' has been written for peoplewith some knowledge of computing, who are thereforeassumed to know what an operating system is likely todo, but who have no experience of Unix. It is, however,assumed that the reader has access to a Unix system sothat he/she may experiment with the commands as theyare discussed.

Chapters 2-4 cover logging into the system and creatingand manipulating files. The editor is discussed, then thefile system with details of directories and permissions.This section introduces the need for particular facilitieswithin a system, shows how Unix is commanded to performcertain functions which support the required facilityand gives examples of the use of the commands. Chapters6 and 8 are written in the same style, and cover the basicsof the Unix shell.

By contrast, chapters 5 and 7 are presented much morein the style of extracts from a manual. A wide range ofUnix commands are covered with plenty of detail andexamples. However, there is less linking material andit is thus more difficult to obtain any feeling for theoverall philosophy and structure.

The final chapter, chapter 9, which constitutes aboutone quarter of the book, is entitled 'System administrator'.As this implies it deals with the duties and tasks of the'superuser' who looks after the system for the usercommunity. Topics such as start up, shut down and dumpsare discussed with details of the commands to performthese. There are also useful sections on trouble snooting.Reading this chapter does fill in some of the general infor-mation lacking earlier; however, it is unlikely that anyonewould tackle this job without access to a full systemsmanual.

As a 'new user' text the early chapters with their tutorialapproach give a good introduction. However, the style anddetail of the remainder of the book does not seem tofollow happily. Full details of commands and optionscan be found in the Unix manuals. Surprisingly the facilityto print sections of the manual is not mentioned.

The Unix system is very open. Many systems are small,having few users. Its considerable cult following has arisenjust because it can be used in an informal way for softwaredevelopment within a project group. So to whom does theauthor aim his text? The software team who themselves

will control and run their new Unix machine seems thetarget readership. As a textbook for students using Unix,the examples form a good beginning. However, theirsystem administrator might be less happy about the'superuser' details divulged in chapter 9. Also a generalsystem overview would make the book more helpful tothem, as well as to those who wish to compare Unix withtheir present system.

Finally a warning: there seem to be a number oftypographical errors remaining in the text and the lay-out of the examples, while usually very clear, is occasionallymisleading. This latter may be due to the computerformatting and typesetting used in the preparation of thetext!

WENDY J.MILNE

Microcomputer system designM.J. Flynn, N.R. Harris and D.P. McCarthy (Eds.)Lecture notes in computer science. Vol. 126, Springer-Verlag, 1982,397 pp.ISBN: 3-54011172-7

This book contains a set of articles based on the CREST-sponsored 'Advanced course on microcomputer systemdesign' given at Trinity College, Dublin, in 1981.

As a software engineer with limited hardware experi-ence, I found the first two chapters of greatest interest,but hardware-oriented engineers would probably find thetwo language chapters and the operating system chaptermore relevant. Approximately one half of the book isconcerned with hardware topics, and the other half isconcerned with software and architecture. This seems tobe about the right balance as it is generally agreed thatmicrocomputer specialists need to be competent in bothhardware and software.

The problem, however, is that many readers will findthat they are familiar with a substantial part of material,and only two or three chapters will interest them. Thematerial covered starts with VLSI technology, treated inthe usual manner, but with extra emphasis on fabricationscience and technology. This is followed with a chapterby Prof. Lewin, on computer aided design. David Aspinall'schapter on classifying the microprocessor at the instructionset level is followed by one by Flynn on customising micro-computers for specific tasks. Two chapters by Perrott onsequential and concurrent languages are followed with oneon microcomputer operating systems by Harris. The finaltwo chapters, by Pope and Wirth, cover distributed systemsand a personal computer, respectively. This problem ofunevenness in appeal is not unique to this book, but appliesequally to the range of books produced from the CRESTcourses.

For the postgraduate student, for which these coursesare designed, and possibly for 3rd-year undergraduates,these books provide a good basic introduction to the sub-ject, and this volume on microcomputers is no exception; itcan be thoroughly recommended for this group of readers.

ROY D. DOWSING

14 Software & Microsystems, Vol.2, No.l, February 1983