Editing Infocom (section)

==Overview==
Infocom games are [[interactive fiction|text adventures]] where users direct the action by entering short strings of words to give commands when prompted. Generally the program will respond by describing the results of the action, often the contents of a room if the player has moved within the virtual world. The user reads this information, decides what to do, and enters another short series of words. Examples include "go west", "take flashlight", or "give the letter to the woman then ask her for a book".

Infocom games were written using a programming language called [[Z-machine|ZIL]] (Zork Implementation Language), itself derived directly from [[MDL (programming language)|MDL]], that compiled into a [[bytecode]] able to run on a standardized [[virtual machine]] called the [[Z-machine]]. As the games were text based and used variants of the same Z-machine interpreter, the interpreter had to be ported to new [[computer architecture]]s only once per architecture, rather than once per game. Each game file included a sophisticated [[parser]] which allowed the user to type complex instructions to the game. Unlike earlier works of interactive fiction which only understood commands of the form 'verb noun', Infocom's parser could understand a wider variety of sentences. For instance one might type "open the large door, then go west", or "go to festeron".<ref>[http://www.lemonamiga.com/games/docs.php?id=1795 The ''Wishbringer'' manual] with more examples of complex commands possible with Infocom games.</ref>

With the Z-machine, Infocom was able to release most of their games for most popular [[home computer]]s simultaneously: [[Apple II]], [[Atari 8-bit computers]], [[IBM PC compatible]]s, [[Amstrad CPC]]/[[Amstrad PCW|PCW]] (one disc worked on both machines), [[Commodore 64]], [[Commodore Plus/4]], [[Commodore 128]],<ref>Infocom was actually one of the very few companies to release game software for the C128's native mode, contrary to most software houses' practice of only catering for the combined C64/128 market (as the C128 was compatible with the C64)</ref> [[Kaypro]] [[CP/M]], [[TI-99/4A]], [[Mac (computer)|Macintosh]], [[Atari ST]], [[Amiga]], [[TRS-80]], and [[TRS-80 Color Computer]].
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