The first King's Quest game originally used a language named Game Assembly Language, or *.gal, by its designer, Arthur Abraham. When its main designer left, Sierra was unable to complete the game, which had been intended to showcase the technology of the IBM PCjr. IBM "donated" its product, AGI, to Sierra to allow development of King's Quest to continue.
When it debuted in the mid-1980s, AGI was innovative and made impressive use of the technology available at the time. Later versions were adapted to use 16 color EGA graphics and the Adlib soundcard.
By the end of the 80s, however, AGI's 160�?�?â�?��?�200 resolution began to show its age and could not compete with newer engines such as Lucasfilm Games' SCUMM, which featured mouse support. In 1990, Sierra abandoned AGI and started using the SCI (Sierra Creative Interpreter) engine for their adventure games.
Sarien (Sierra AGI Resource Interpreter Engine) is a portable, open-source re-implementation of Sierra's AGI.
List of AGI games
- King's Quest: Quest for the Crown (1984)
- King's Quest II: Romancing the Throne (1985)
- The Black Cauldron (1986)
- Donald Duck's Playground (1986)
- King's Quest III: To Heir is Human (1986)
- Mickey's Space Adventure (1986)
- Space Quest I: The Sarien Encounter (1986)
- Winnie The Pooh in the Hundred Acre Wood (1986)
- Leisure Suit Larry in the Land of the Lounge Lizards (1987)
- Mixed Up Mother Goose (1987)
- Police Quest: In Pursuit of the Death Angel (1987)
- Gold Rush! (1988)
- Manhunter: New York (1988)
- Space Quest II: Vohaul's Revenge (1988)
- King's Quest IV: The Perils of Rosella (1988) *
- Manhunter 2: San Francisco (1989)
* King's Quest IV was simultaneously produced and published in both the AGI and SCI formats. The main advantages of SCI are a higher resolution (320x200 rather than 160x200 in AGI), sound card support, mouse support, and a more versatile scripting system. Sierra supposed that contemporary low-end systems would be unable to run the SCI version, thus requiring a 'lighter' version of the game. However, sales figures proved them wrong, and the AGI version was quickly discontinued. Because of its rarity, the AGI version could be considered a collector's item.
Since AGI was reverse engineered years ago, there are many freeware programs which allows you to create your own AGI games. In fact, a good amount of people have made their own AGI games which you can play using Sarien. At the Ultimate AGI & SCI Web Site link listed in external links, you will find programs to create your own AGI games & also be able to download homebrew AGI games created using the freeware AGI design tool.