Infocom/Inform Text Adventures on the QL By Tim Swenson In the Beginning "It is a dark and stormy night. Lightening illuminates the room you are in. Briefly, as the lightening flashed, you can see that you are in a large library that seems to be part of a castle. The room is full of books stacked on the shelves and everywhere else. One the table before you is a parchment scroll, a candle, and a match." This is the start of a text adventure game. In the late 70's, Will Crowther and Don Woods created the first popular text adventure game, "Adventure." Scott Adams picked up the idea and wrote a number of successfull adventure games for the TRS-80 computer. Sierra Games picked up the style, added some graphics, and wrote text adventures for the Apple II. "The Quill" was a system used on Spectrums to make many commercial text adventure games. It was Infocom that took the text adventure to a higher level. Infocom developed a system that made the game in two parts, an Interpreter and a game data file. Since the user interaction part of each game was the same, Infocom created an interpreter that could be used with all of their games. The game was stored in the game file (in a "Z-Code" format) and read by the interpreter. To cover a number of different computer platforms all they had to port was the interpreter. The game data files did not have to be altered but could be used on any platform. Infocom was able to create games for MS-DOS, CP/M, Apple II, C-64, and other platforms. The Infocom game format was so popular that people started copying it for thier own purposes. Mark Howell wrote a Z-Code interpreter called "ZIP" (not to be confused with the archive utility of the same name). To create the games, Graham Nelson wrote "Inform" a compiler of Z-Code games. It uses a C-like language to write the text adventure games. Many enthusiasts of text adventure games ( or "Interactive Fiction" as it as also called) have used Inform to create their own games. There is even a yearly competition for writers of Interactive Fiction. These two utilities have been ported to many computer systems, including the QL. Luke Roberts has ported both ZIP and Inform to the QL, letting QLers both develop and play text games. ZIP There is not much to say about ZIP except to say that it works. The original distribution from Luke Roberts comes with two games to get you started. exec zip;"curses_dat" This is all it takes to start playing. From this point you have an angle backet prompt for entering your commands into the game. The games come with few instructions and you are supposed to puzzle it out for yourself. In fact, the whole idea of adventure games is to figure out the puzzle. ZIP also comes with a few utilities to "assist" your play (read that as "cheat"). Infodump extracts information from the game data file, allowing you to see inside the game. Txd is an Inform disassembler that turns a data file into a Z-Code file. You have to know Z-Code to really use Txd. INFORM If you actually have the interest in developing text adventures, Inform is the system that lets you do it. Inform uses a language fairly similar to C letting you be fairly expressive about how you want the game to run. Inform compiles the source code and creates a Z-Code file that is then used by ZIP. Since Z-Code files are portable, any adventure that you create on the QL can also be used on any other platform that has ZIP. Inform comes with a fair amount of documenation and a number of source code example games. Since Inform is a language, you will have to put for some effort to really develop a game. It is powerfull but trivial to learn. Inform comes with a couple sample adventure files (_inf). The sites listed below also have a number _inf files. These can be compiled to the resulting game file or you can study them to see how the games were made. The Games Now we come to the key point. I've sure that there are not many QLers interested enough in text adventures to write games for other QLers. But, since the game files are portable we can use the games written for the other platorms. I was able to find a few key sites on the Web that store Inform games. These sites are: Snacky Pete's Text Adventure Archive http://www.helikon.com/Personal/Pete/Advents/iflib.htm Inform Programming http://www.cl.cam.ac.uk/users/gdr11/inform/ Combined, there are about 30 games available. The second site has a number of example Inform files that show how various actions are done in Inform. A version of the original Adventure is available, along with: Adventureland (by Scott Adams), Paper Chase (the object is to get a college degree), Detective (using the characters from "Mystery Science Theatre 3000"), Odieus's Quest for the Magic Flingshot, Busted! ("a game of high cunning and low humor"), and others. Some games are small (43K) and other go as high as 224K. I'm assuming the larger the game file the bigger and more complex the game. If you visit the Activision home page, they are giving away a free copy of Zork I, the most famous Infocom game. They are giving away the MS-DOS version, but you can copy the ZORK1_DAT file to the QL. I've downloaded a few of the games (including Zork I) on these pages to make sure that they will run on the QL. Z-Code came in different versions, with version 3 and 5 being the most popular and these are supported on the QL version of ZIP. There are some games written in version 7 and 8, but these games will not run on the QL. There are even a few e-zines that support text advetures. XYZZY News and SPAG Newsletter (Society for the Preservation of Adventure Games) are both available via the Web (use Yahoo or Lycos to find them). Both of these newsletters have fairly current issues, meaning that there are still people out there writing Inform text adventure games. Having ZIP ported to the QL means that we can take advantage their efforts and play these games ourselves. The Files Both Inform and ZIP may be available on a QL BBS near you. For North American QLers, they are available on QBOX USA and from QHJ Freeware (me) at the address below. They were available on maya.dei.unipd.it, but I think it had a disk crash. You should still find them on one of the mirror sites, like ftp.nvg.unit.no. QHJ Freeware c/o Tim Swenson 5615 Botkins Rd, Huber Heights, OH 45424 swensont@mail.serve.com http://www.serve.com/swensont/