Action! — Atari Computers

A compiled language on cartridge

Action!, created by Clinton Parker and published by OSS, gives Atari eight-bit programmers structured procedures and fast compiled 6502 code. Its cartridge contains an editor, compiler, and monitor. BYTE, INT, and CARD types let a program work with small integers and memory addresses directly.

Example: greet the Atari owner

Action! — a complete cartridge example

PROC Main()
  BYTE count

  FOR count=1 TO 3
  DO
    PrintE("HELLO, ATARI PROGRAMMER!")
  OD
RETURN

Expected result: three greetingsIllustrative preview

HELLO, ATARI PROGRAMMER!
HELLO, ATARI PROGRAMMER!
HELLO, ATARI PROGRAMMER!

The loop calls PrintE three times, placing each greeting on its own line. This is the program’s output; the Action! monitor resumes afterward. The preview assumes the usual blue text screen.

Enter the listing in the Action! editor. Switch to the monitor with Control+Shift+M, use C to compile the editor buffer, then R to run. The loop prints three greetings. PrintE is the cartridge library procedure that adds an end-of-line after the string.

This example runs with the Action! cartridge present. Distributing a program that uses cartridge library routines without that cartridge requires the appropriate runtime support. The last procedure in an Action! source program is the entry procedure; this example has only one.

Reference: OSS Action! Reference Manual and reference card.