Kail Paul A.C. An introduction to Forth

Micro Books, 1985. — 128 p.FORTH is a very unusual and exciting language. It is fast, compact, and very versatile. A good FORTH program can run at up to three-quarters of the speed of the equivalent machine code version; yet at the same time, for many applications it is as easy to use as BASIC. FORTH is also a language of the future. It is available for most home micros, and is being used increasingly to control home robots. Unlike any other computer language,
the range of words that it contains can be easily extended lindeed, this is the basis on which programs are written): it can therefore be adapted to suit a wide variety of applications. In s o m e ways it is quite primitive: it uses a "stack" rather than variables (although variables can be defined as well), it uses Reverse Polish Notation and it lacks many of these functions such as sine and square root which are built into other languages.
However, the functions can easily be defined and added . The advantages of FORTH more than make up for these defects.