This is yet another BBC user port interfacing manual. Programming the user port VIA chip is well explained, including information for the Master. The hardware designs follow for an LED output monitor and switch input unit, which are both well laid out on Veroboard, and control programs are provided.

There is a brief introduction to transistor driving, although the explanations are insufficient to allow intelligent user implementation - you just copy the drawing. This is not very helpful - an explanation of principles is essential if books like these are going to serve any real purpose.

The author then goes on to describe a mains control unit built on Veroboard. Apart from my usual reservations about connecting beginners to the mains, the use of Veroboard is downright lethal. It simply can't take that much power.

Supposing the reader has survived this chapter, the projects that follow are quite interesting. Information is provided on sensor interfacing, albeit on a crude level in some cases. A notable example is the use of light dependent resistors. Both the simpler and the 'improved' versions could suffer from serious stability problems that the author has not seen fit to mention, and although analogue output is covered to moderate precision, no attempt has been made to sense analogue inputs except in the simplest 'go/no go' terms.

The inevitably buggy 'robot' has some quite nice touches. Not least is a perfectly feasible dark line follower using four sensors: much better than the usual two.

The book is generally well presented, but the computer graphics throughout would have been much clearer had they been conventional artwork.