Memory: 48/80K
Price: £14.95

From East London Robotics, 48/80 Forth is a full, integer implementation of the language, based on Fig Forth, with additional words defined to use the colour, sound and graphics capabilities of the Spectrum. While it will work on the 48K machine it can also be used by users who have the ELR 80K memory upgrade.

To use the Forth editor it has to be loaded from tape and will give a total of 16 screens, 32K on the 80K version. Each screen consists of 1,024 bytes, made up of 16 lines of 64 characters.

The instruction booklet supplied with the tape gives a very brief introduction to the language and shows how a word can be defined. It also explains the operation of the stack and has a few examples to show loops, conditionals and variables. Beginners, however, will need to buy a book on Forth to obtain the best from the program.

The booklet has a complete glossary of all the predefined words and the appendices list the error messages, memory maps and the necessary information to write your own machine code definitions.

Overall, this is a reasonable but average implementation. If you have the memory upgrade, however, it becomes a far better proposition because of the space available.