Publisher: Interface. 9-11 Kensington High Street, London W8 5NP
Price: £2.99

If you have not learnt about the joys of Logo then Spectrum Plus Logo, by Tim Hartnell, provides everything you need to get started.

It is not just a book of pretty patterns produced by short listings. Hartnell has produced a version of Logo, close to the LCSI standard which is included in the book. He starts with a brief introduction to turtle graphics and shows how the language can be applied to the real world using a floor turtle to draw mathematical patterns.

The rest of the book deals with how to use Hartnell's Logo-K language, the listing for which is reproduced at the back. Hartnell uses a simple style, in text and listings, but does not miss an opportunity to show that Logo is a fun, as well as being an educational, language.

The example listings may be short - some of them are only three lines in length - but they all produce spectacular results. Starting with a simple recursive flag design Hartnell shows that there is art in the mathematics of angles. By the time you reach the end of the book you will be reproducing patterns to equal spirograph creations and have lost your fear of mathematics.

At £2.99 the book represents excellent value. Although Logo-K is written in Basic and produces turtle graphics slowly it will respond to a large number of commands.

The book is ideal for schools and colleges where it could be used as a general text on Logo and a source for an implementation of the language which students could type into their home machines. Tim Hartnell has come up with an educational winner.

This is published by Interface Publications and written by the Master-over-all-computer-books, Tim Hartnell. The book claims to provide you with a program which will turn your ZX Spectrum into a LOGO based machine.

For those of you not in the know, LOGO is a graphics programming language. It was invented for the purpose of introducing children to computers, and allows an imaginary turtle to be controlled as it moves around the screen to produce various designs and pictures. The LOGO program in the book conforms to the LOGO COMPUTER SYSTEMS, INC vocabulary. This enables the experienced user to enter the world of LOGO and one that is compatible with other systems.

The program is well written and is listed in two versions with and without the REM statements. This is an excellent idea, not only to fill the book up with a few extra pages (!) but also as the total novice to computing only wants to type in the necessary lines and not bother with pointless keying in. For the more experienced programmer, the REM's are very well detailed and give an excellent view of the program's action.

The book is written in a friendly, easy to understand way. From the introduction, right through to the many examples, the reader is taken at a steady pace through the learning process, starting with the basics of the language and then progressing, so that by the end of the book an in depth knowledge of LOGO can be achieved.

Included in the book are numerous LOGO examples, from a six-sided figure (called a sexygon by Tim Hartnell) to lots of tiny SIR CLIVE's, holding hands in a circle.

The book is a bargain at £2.99, even for the experienced reader who finds Tim's teaching a bit simple, as the LOGO emulation is very good. My only grumble being the speed at which LOGO runs, but this can only be blamed on Sinclair and not the author.