AGI/Specifications

AGI Specifications v3.2, 17 July 2007

Lance Ewing, Peter Kelly, Claudio Matsuoka, Stu George, David Symonds

This document is a collection of all the information currently known about the structure and operation of the Adventure Game Interpreter, used in 1984--1989 for a variety of adventure games published by Sierra On-Line such as Space Quest I and II, and Leisure Suit Larry in the Land of the Lounge Lizards.

   * 1.1 About
   * 1.2 Audience
   * 1.3 Conventions used in this document
   * 1.4 What's still missing
   * 1.5 Change log
   * 1.6 Credits

General AGI overview

   * 2.1 Versions of the AGI interpreter
   * 2.2 AGI game files
   * 2.3 LOGIC, PICTURE, SOUND, and VIEW data files
   * 2.4 What is Ego?
   * 2.5 AGI commands
   * 2.6 Debug modes
   * 2.7 Priority bands and control lines

AGI internals

   * 3.1 How the interpreter works
   * 3.2 Variable types
   * 3.3 Variables used by the interpreter
   * 3.4 Flags used by the interpreter
   * 3.5 Memory organization
   * 3.6 Game IDs and loaders
   * 3.7 Encrypted AGI data
   * 3.8 Player input parsing
   * 3.9 AGI interpreter versions
   * 3.10 Version differences

The LOGIC language

   * 4.1 LOGIC syntax
   * 4.2 Reference of the LOGIC commands
   * 4.3 Discussion of sample LOGIC code from KQ4 

Formats of the resource files

   * 5.1 Directory files
   * 5.2 Format of Vol files (version 2)
   * 5.3 Format of Vol files (version 3)
   * 5.4 Sample code

LOGIC resources

   * 6.1 Introduction
   * 6.2 Command list and argument types
   * 6.3 LOGIC resource format

PICTURE resources

   * 7.1 Introduction
   * 7.2 PICTURE resource format
   * 7.3 Implementation
   * 7.4 Using higher resolution modes
   * 7.5 Sierra's picture editor
   * 7.6 Sample code

VIEW resources

   * 8.1 Introduction
   * 8.2 VIEW resource format
   * 8.3 VIEW table
   * 8.4 VIEW test commands
   * 8.5 Sample code 

SOUND resources

   * 9.1 Introduction
   * 9.2 Sound in the IBM PCjr
   * 9.3 Sound in the Apple IIgs
   * 9.4 Sound in other platforms
   * 9.5 SOUND resource format (PCjr version)
   * 9.6 SOUND resource format (IIgs version)
   * 9.7 Playing the sounds on a sound card
   * 9.8 Sample code

Other game data

   * 10.1 Format of the object file
   * 10.2 Format of words.tok
   * 10.3 Sample code

Other information

   * 11.1 The AGDS package
   * 11.2 The making of the Thunderstorm educational Program
   * 11.3 Other AGI interpreters
   * 11.4 Fan-Made Extensions to the AGI Engine