mosiac of the ESCAPE button to function, and the program got lost after tesselating a pattern and only responded to BREAK. The Escher program locked out also when painting a quadrilateral and also a HEX2 pattern.

The tesselations themselves are quite fascinating to play with and some very interesting colour effects can be seen. Figure 2 shows a pattern developed from two squares of equal size. Dumping the patterns to a printer is easiest if it is an Epson, the only printer catered for. However, the printer routine is in BASIC and

Figure2. Pattern developed from squares of equal size

assembly language and can be listed. It can thus be modified or replaced. The design has to be dumped by the program onto a 40-track disc and then picked up by the printer routine under the filename Screen.

Value for money? Perhaps for school where it is not likely to be played with for a while and then filed away. However, if used there, it would be better as a demonstration than for pupil exercises because of its peculiarities.

W H P Leslie Glasgow, UK

Light-hearted approach to MSX-BASIC

takes the myth out of programming

Jonathan Pearce and Graham Bland

'MSX-- an introduction" Century Communications, London, UK (August 1984) £7.95 pp 166

The idea of this book is to teach the average person 'everything you need to know in order to write both enjoyable and useful programs in MSX BASIC' (MSX BASIC being one of the computer languages available on several personal computers). The book is written with a friendly and light-hearted approach which takes the myth and possible initial fears out of computer programming for the beginner. Unfortunately there is no index and because of poor proof- reading there are many spelling mistakes, omission of spaces between words and incorrect references.

The book begins with a series of short explanations of buzz words, various pieces of hardware and peripheral attachments. It's nice to see a chapter dedicated to these topics in a book which is essentially oriented to software. It gives the first timer a better insight of the overall operations of a computer.

The second chapter introduces the reader to the software or programming side of computers. Definitions and formats for each verb are given comprehensively and clearly but a simple error may result in mayhem for the first-time programmer. For example, the LIST command on page 26 is very confusing. There are four examples of this command, three of which have the same structural format but apparently perform different func- tions. A hyphen was omitted from two of the examples, making them unintelligible. The reader, unless helped by some outside source, could only use the LIST or LLIST commands as they are presented to a limited extent.

The subsequent small sections deal with graphics commands, loading and saving programs and several other topics. The end of the chapter deals with verbs that are fundamental to the language. Regret- fully these verbs are used in examples of other verbs before definitions are given for them. This may lead to confusion for a beginner.

Just an interesting point on pages 34 and 35: there is a definition of the

verb PAINT, immediately followed by an example 1 but not of the PAINT verb as suggested, since 'PAINT' is nowhere to be seen in the example. A similar mistake is made in the next chapter on pages 56 and 57 which mentions an example which should be tried but which is nowhere to be found. Unfortunately these pages seem to refer to the O N . . . G O T O verb and the PRINT verb in the same paragraph.

The reading of this chapter and the ones that fol low is nevertheless enjoyable and easy to understand. Besides spelling mistakes and inaccurate references (eg to a page 000 and Appendix A instead of Appendix B), the commands and concepts are set out well and explained clearly. But eventually the errors, because of their number, became quite annoying.

There are four appendices dealing with functions, error codes, control keys of the screen editor and differences between SV BAStC and MSX BASIC. These are laid out well and easy to read. They are direct and succinct, leaving little to the imagination.

At a price of £7.95 and in its present condition I would find it hard to recommend this book. If the mistakes were corrected, a beginner could then set out to learn all this book has to offer. If I were a beginner I think I'd wait for the next edition.

David Browne ABC 5oftware, Dubfin,

Republic of Ireland

vol 9 no 6 july/august 1985 311