Anyone starting to tire of playing ready-made games on a newly-acquired home computer and wondering how to answer the inevitable enquiries of 'Yes, but what else can you actually do with it?', is likely to find that graphics and sound are among the most attractive areas of initial attempts at writing programs. This book, while not specifically setting out to teach general programming techniques, could provide a starting point for Electron owners who have little other programming experience, as well as being a source of reference for more established programmers who want to find out more about the areas of graphics and sound.
As far as the graphics are concerned, the book starts from scratch by explaining their potential use and how the video display is produced. Line and point plotting, colour, character graphics, graphs and charts, animation and elementary three-dimensional plotting are covered in subsequent chapters.
simple trigonometrical theory is introduced where it's necessary.
The first of two chapters devoted to sound covers the SOUND and ENVELOPE commands and demonstrates how they may be used to generate sound effects. The second contains some elementary music theory and shows how the Electron can be programmed to generate tunes and chords, and be turned into a simple keyboard instrument.
There are plenty of program listings throughout to demonstrate the points made in the text. They are clearly laid out and amply commented on so that they may not only by typed in and run but also understood by the inexperienced programmer.
I was glad to see that the programs in this book, on the whole, make good use of BBC Basic in that, although some use GOSUBs, procedures and local variables are introduced in the second chapter.
As a minor grumble, it ws disappointing to find that a sketching program in the first chapter is terminated by jumping prematurely out of a FOR...NEXT loop. The technique will work in this particular case, but is defefinitely not to be recommended.
In general, the book succeeds as a useful introduction to its subjects while demanding no great degree of previous programming experience.
1st December 1985
