System reference manual and description
ACTION! is a complete software development system for the Atari 8-Bit computers. It was created by Optimized Systems Software, Inc. and Action Computer Services. The following text is from the back of the August 1983 ACTION! System reference manual and will give you a good description.
The Best Complete
Software Development System
The Fastest, High Level Language Available for the Atari:
A versatile, structured language that runs at almost assembly language speed (100 + times faster than BASIC).
Best Structured Language:
Incorporates features found in PASCAL, C, ALGOL, and ADA, yet has many of the same commands familiar to Atari BASIC programmers.
Has Everything You Need:
THE EDITOR: Many advanced features for easily creating and modifying source text…two separate program windows, each allowing up to 249 characters per line…fast horizontal and vertical scrolling…move and copy text…string find and replace…and much more!
THE MONITOR: Selects compilation options, saves compiled programs, examines variable values and memory locations…and even traces the execution of your programs.
THE COMPILER: Super fast compilation into machine code, accepting source from the Editor or from tape or disk.
THE LIBRARY: A built in collection of useful subroutines for you to use in your programs including: string manipulation…print procedures and formatting…I/O routines…and, graphics and game controller routines.
Visit: The ACTION! homepage