The ZX81 has followed rapidly on the heels of the ZX80, which has outsold almost every other type of personal computer made. The main reasons for its success are its low cost and simplicity - a unique combination.
In March 1981, Sinclair released the new ZX81 - more features, better casing, and even lower cost! How can it possibly fail to be another winner? Most of the computer press has given glowing reports of its capabilities. If you are learning, then it really is ideal.
This is our second book along these lines (the first is The ZX80 Pocket Book) and the content is entirely new. I have attempted to keep similar quality to this book, although the style is hopefully less clinical and the layout less fixed.
If you have a ZX80, you should purchase an 8K ROM upgrade before launching too deeply into this book, as all the programs have been written for the ZX81, and not for the ZX80 with "And ZX81!" just printed on the cover. This is important as the two machines are really quite different.
The vast majority of ZX81's sold will not have the additional 16K RAM pack fitted and so there is quite a large selection of assorted "goodies" for these people. Personally, I feel that the machine just cannot be used to its best without this extra RAM pack and I would strongly urge you to buy one if the computing "bug" gets hold of you in any way. Perhaps Santa may be feeling a bit more extravagant - who knows?
Newcomers to computing will hopefully find something more challenging than just another set of games to copy and run - I sincerely hope that you will learn along the way and maybe have a laugh or two. If you are relatively new to programming, you will find it very easy to fall into the habit of purely typing in programs written by other people and running them. This is not programming - most people can type. Try to develop a style of your own, using some of the ideas in this book to fuel your imagination. There is much more pleasure to be gained from running a program that is your own handiwork - especially if your friends become rather attached to it.
