Practical Hardware Projects by Joe Telford, published by Century Communications. Price: £8.95. Recommended reading for anyone about to embark on the tricky subject of interfacing and hardware project building. It's a big leap from software to hardware. You have get your hands dirty, so to speak. A whole new set of skills have to be learned and this book is less likely to baffle you than any yet published for the BBC Micro.

It assumes no previous knowledge of the subject, repeats information and tips where necessary and uses clear diagrams. The descriptions of equipment leaves no doubt about what you should ask for at your local electronics store.

Interfacing concentrates on the analogue, user and cassette (motor control) ports. Starting with the make-up of suitable connectors, each section, on analogue and on user port, details a number of interesting projects. For analogue port: voltage, ohm, capacitance and amp meters; measurement of heat and light, a touch switch and a paddles/joysticks section. For user port: a coinboard, windspeed meter, piano type keyboard, output buffer, LED indicator, traffic lights simulator and relay board; a combination lock, movement detector and accelerometer.

There's a section on controlling motors, which leads into Beebuggy, its control and monitoring feedback from it. This involves following a white line, an obstacle detector and gradient detector and 'Drop' detector.

The final chapter presents three "upgrades" or modifications for the BBC Micro itself. The hardware disabling of the Break key has and will find applications in schools and where the BBC is used for display purposes. Fitting a DIL switch to the keyboard links enables a choice of screen mode at start-up, auto-boot on Break and selection of disc drive speeds. If you've got shadow RAM or a second processor why not show off and start up in the Mode of your choice?

The last of the three projects is a simple but effective software protection device and will spark off many further ideas. An analogue port dongle doesn't stop those who wish to hack the code but it's a nice project to demonstrate the concept. A list of suppliers and an external power supply are the standard appendices which complete the book.

Because the projects are based on the author's practical experience, they should prove ideal for the classroom with one team debugging the software, another laying out component on Veroboard, coming together to test and then use the resulting device. The hobbyist breaking new ground will also find a friend in this well produced book.