ZX Spectrum BASIC programming, Bradbeer Robin Vickers Steven

Whether you read the Introductory book first, or came straight here, you should be aware that commands are obeyed straight away, and instructions begin with a line number and are stored away for later. You should also be aware of the commands: PRINT, LET, and INPUT (which can be used on all machines that use BASIC), and BORDER, PAPER and BEEP (which are used on the Spectrum).
This BASIC manual starts by repeating some things given in the introductory booklet, but in much more detail, telling you exactly what you can and cannot do. You will also find some exercises at the end of each chapter. Don't ignore these; many of them illustrate points that are hinted at in the text. Look through them, and do any that interest you, or that seem to cover ground that you don't understand properly.
Whatever else you do, keep using the computer. If you have the question "what does it do if I tell it such and such?" then the answer is easy: type it in and see. Whenever the manual tells you to type something in, always ask yourself, "what could I type instead?", and try out your replies. The more of your own programs you write, the better you will understand the compute
At the end of this programming manual are some appendices. These include sections on the way the memory is organised, how the computer manipulates numbers, and a series of example programs illustrating the power of the ZX Spectrum.