SPECTRUM RULES THE WAVES

Every publisher in the UK seems to have discovered the Spectrum, so there is sure to be a bumper crop of reading matter for Spectrum owners in the coming months.

Our review panel have been looking at a selection of the Spectrum books and finds that the standard is uniformly high (both in terms of content and presentation), with each book representing value for money in its own way.

This book is in many ways a sequel to Ian Stewart and Robin Jone's book 'PEEK, POKE, BYTE, & RAM' which enjoyed so much popularity as a beginner's guide to the ZX81. Here then is the what to do next, or 'What do I do now that I've added a 16K RAM pack'. Clearly Stewart and Jones' answer is 'learn how to improve your ability to program in BASIC and start on machine code programming'.

This book is part of Shiva's 'friendly micro' series, and as you'd expect, it is written in a friendly way designed to make you feel at ease even when rather complex matters are being discussed. From this point of view the book is generally a success. About half of it is on improving your BASIC and the latter half is on acquiring a grounding of knowledge of machine code. The first section covers topics such as using data structures in general, and such things as arrays, stacks, queues and 'trees' in particular.

Whilst the writing style is warm and friendly, the text may not always be clear to all who read it as their very next step after 'PEEK, POKE'. The section on arrays, for example, contains a host of useful information, but one cannot help thinking that the subject matter could have been presented in an even more simplified fashion. The section which follows it on searches, is surprisingly only three pages long and only deals with 'binary searches'. A more thorough simple guide to a variety of search methods might have been useful.

Introducing the reader to stacks next seemed a little out of place, although I'd acknowledge that other readers might feel differently. It is not entirely clear, I'd imagine, to someone without a fair amount of experience of computing what a stack might be used for - and the 'Tower of Hanoi' example Stewart and Jones give would not necessarily have enticed me to spend long on this section were I a beginner. Perhaps the fact that they are laying ground here for their introduction to machine code could have been made clearer.

The central section on structured programming is generally well presented and we are led through three longish 16K programs.

MACHINE CODE

The last half of the book on machine code is certainly a worthy effort, but I am not convinced that it succeeded as a plain man's guide to learning machine code. The task is certainly daunting, but throwing the reader straight into HEXadecimal was not perhaps the best approach. Nor perhaps was introducing a fictional central processing unit 'which might have been built in the 1940's, but it wasn't'. Moreover, the first machine code the reader is introduced to is not machine code at all, but half way there in pseudo mnemonics - perhaps a little confusing to those who know a little about machine code already.

All in all, then a generally good followup to PEEK, POKE, if not quite as successful in accord with its aims as the earlier book. Undoubtedly useful for those who have gained some mastery of their ZX81 and want to go further, but like so many books for popular microcomputers, I would urge that this book be read alongside others aimed at a similar level.

MACHINE CODE AND BETTER BASIC COSTS £7.50 (and is, we feel, rather overpriced).