An add-on software package designed to improve Logo's rather unfriendly interface is given a thorough classroom workout by Roger Frost

One of the main problems experienced by teachers when trying to encourage pupils to enthuse over Logo is the language's decidedly unfriendly startup prompt. The Logotron version - which is now the standard - simply presents a question mark as a prompt, which can be a stumbling block for some pupils who then don't know what to do next.

For them, Turtle Worlds - the company and the product have the same name - may well provide the answer. It runs on the Electron providing you have an AP4 disc interface.

Logo, a very powerful computer programming language, is set to form part of the national curriculum for many schools. The Logotron version has many in-built extensions like control and music, but many teachers are alarmed about how their pupils will cope with any variant on the basic Logo theme.

Now Turtle Worlds transforms the appearance of the language into something bright and colourful by allowing users to work on screens loaded as backgrounds.

The package consists of two discs and a very well-written manual. The aim of authors Richard Parker and Chris Morley is to make Logo accessible and easy to use. All that is needed is to insert the main disc, press Shift and Break and let the software set itself up. After a short wait, a very pleasing Turtle screens loads, followed by the main program.

The menu displays a list of the ready-made screens provided on the disc. These pictures are based on a supermarket theme, with a plan view of the car park, the front of the shop, a plan of the inside, shelves, tins of peas, some fruit and a final picture of loading the car with shopping.

These screens are only the beginning, as it is easy to create your own and add them to a Turtle Worlds Library disc. User-friendly utilities are provided to convert raw screens to Turtle Worlds format.

There are three other main features, the first being the extra Logo Keywords provided:

SETCOL allows screen colours to be altered and is equivalent to the Basic VDU 19 command, but much easier to manage. This is required to allow Turtle Worlds' screens to be displayed in the colours they were originally painted in.
1. RESET sets all colours back to their default values.
2. PANIC will regain work space at the expense of defined procedures. This could be a lifesaver for Logo users.

The other two features are designed to make the user interface easier to manage. The first, simple method is to define function keys with the more frequently used Logo keywords. The second technique is to set up a Concept keyboard.

An A4-sized overlay is provided with the pack. It can easily be photocopied and enlarged for A3 size keyboards.

The best part of Turtle Worlds is the section in the manual devoted to ideas for its use. Although simple, they will set youngsters thinking about geometry without realising it as they perform some other task. An example involves the car park plan. One suggested idea is to move the turtle along roadways to an empty parking lot and then to construct a simple plan view of a car.

Changing the colour of items on screen - a satisfying process - will require the turtle to be placed inside the object. Distances and angles will need to be estimated here. A particularly popular idea is to colour the fruit so that it looks bad.

A pity the printer option is for black and white Epson-compatible devices.

Turtle Worlds could be the way to bring any school's Logotron Logo to life. It is thorough, very user-friendly and an absolute snip at £12. Recommended.