OK, so you've got your ZX81, and you've learnet how to program it, but now you want to do something really useful.

This book will give you a review of various hardware available to add on to your Sinclair ZX81, plus some useful programs to help make them work.

Projects to set up yourself include:

light sensor

burglar alarm

voice recognition system

an educational experiment to find g

flashing Christmas tree lights

Packed with pics and information!