THE EDUCATIONAL value of games has been discussed in the computer press but little has been said of any practical value. Microcomputer Game Design, by Michael Rigg, develops the theme and shows that most of the effort of producing a game is in design.

Unlike many writers, Rigg does not treat any one language as inferior to another. They all have their good points and even Basic has some advantages.

The book deals with some unusual languages, such as Prolog and Comal, showing that they can have some importance in the area of games design.

Once through the process of design, coding and debugging - three processes which can often happen simultaneously - the author looks at the aspects of design such as graphics, colour and sound. He uses the Melbourne Draw program, available for the Spectrum, to create background displays, and then shows how best to cope with hundreds of Beep commands in an effort to produce interesting sound.

Following that, Rigg launches into the design of an adventure. Although the emphasis is on programming your own adventure - on any machine - the author does talk about utilities such as The Quill and how it is better to use them if you do not require any stunningly original effects. Rigg produces an entire game - called Jason - from plan to program and demonstrates that The Quill and other such utilities are more than tools for amateur programmers.

If arcade game designers are feeling left out they need not fear. The book includes a section on Ocean's White Lightning which creates background graphics and sprites using a language similar to Forth.

Machine code is, justifiably, the last aspect of game design to be dealt with by Rigg. There is nothing new in the section, but the author points the beginner in the right direction. Sparse details are given of number bases followed by basic information on such machines as the Spectrum and the Commodore 64.

The book shows that although playing games may be educational, writing games is more so. Rigg has a natural and lively sense of humour which pervades the explanations.

Rigg may not turn you into a programming genius but his book will show you where the first signpost is.

COMPILATIONS are a good way of maximising profits for a publishing company. Titles can be re-released in bundles and packaged to attract a new audience.

Dorling Kindersley has now published compilations of its screen shot books. The Screen Shot Starter Pack for the Spectrum Plus is designed to help the beginner and comes with book one and two of the series, together with a typing tutor. The two books take the beginner through all the main commands together with simple routines which can be used elsewhere. There have been a great many books published for the beginner, but these books are among the best, due to the fact that each routine is illustrated in full colour with its appropriate screen shot.

The typing tutor is pretty standard, beginning with the home keys on the keyboard and training you both in accuracy and timing.

The Screen Shot Graphics Pack follows the same format with ample illustration and explanation of what each program does. Using DATA statements incorporating machine code instructions some very fine results can be obtained. Book three covers lines, circles and filling shapes while book four moves on to sprites. There is a library of sprite shapes which can be used.

The accompanying tape demonstrates all the routines together with technical details. There is a simple graphics editor and a sprite editor.

I would recommend both packs either for the beginner or the more advanced programmer as the routines can be used easily in other programs. The quality of layout and illustration is an added incentive.

There is only one quibble and that is the price - most compilations tend to work out cheaper than the original publications, but these don't. They do, however, make attractive gift packages as an all-in-one box.

YOU CAN stuff anything into the front of a diary these days and Pitman has added another string to its 1986 bow.

The Sinclair Reference Diary, by Clive Gifford and Tim Hartnell, is just one of a range of computer diaries launched for those of you eager to find a way to fill your loved ones' stockings. Approximately three-quarters of the slim publication is filled with dates - a week to a page - and the rest devoted to computer facts relevant to the Sinclair owner.

The authors tell you everything you already know about your machine and the others which Sinclair has launched, including the ZX80. It gives information about peripherals, Spectrum RAM map and system variables.

The back of the diary contains a London tube map and the principal rail services. There's also a forward planner for 1987. I've made a note not to buy this diary next year.