The Z-Machine

In 1979, a number of DM group members wanted to work with each other outside of the research lab. To keep the group together, they decided to form a company. In retrospect, it seemed like a na´ve thing to do, since they had no plan, product, or even an idea about what sort of work they would be doing. Each founding member was called upon to contribute some amount of money from $400 to $2,000, with the percentage of the resultant amount being proportional to the stock that each founder would receive. On June 22, 1979, Infocom was officially incorporated.

During the founding days, "nobody thought particularly about doing Zork as a product." The original intent was "to do something serious." However, once the company was founded, the employees quickly realized they needed to sell something, or they would be out of business before they were ever really in business. Since they didn't have a new product ready to sell, they decided to try to market Zork. They already had a working prototype for a DECsystem-10, and Berez and Blank were excited about making Zork run on microcomputers. Zork was not considered a serious product, but the founders thought that it would bring in some revenue to give the company a start.

At the time Infocom was founded, Personal computers cost a few thousand dollars each, and owners tended to be wealthy and well educated. Doctors, businessmen, lawyers, and other professionals could afford the price tag. The owners of the personal computers tended to enjoy reading-a factor that would prove critical to the success of Infocom's games. The emerging personal computer market presented a golden opportunity for Infocom, but its founders faced a difficult challenge: How could they make Zork, which barely ran on a DECsystem-10, work on comparatively tiny microcomputers? Making Zork fit on personal computers

Berez and Blank knew it would be a daunting technical task-they would be faced with limitations on all fronts, from memory size to processor power. And to complicate matters, they would have to support multiple platforms, since there was no clear market leader in the home computer business. Taking the idea of UCSD Pascal one step further, Berez came up with the idea of making a design for an "imaginary computer chip" specifically designed for text-adventure games, which he called the Z-machine.

Berez and Blank realized that it wasn't absolutely necessary to keep all the program code loaded in main memory, thereby reducing the memory requirements. Instead, the Z-machine could leave the bulk of the code on disk and load certain sections into memory whenever the program called for it. This idea drove Berez and Blank to employ one of the earliest virtual memory managers for the personal computer.

In addition to simply making it possible for Zork to fit on a personal computer, the Z-machine also facilitated portability to virtually all models of personal computers. This was important because Atari, Apple, Commodore, IBM, NEC, Radio Shack, and other companies had models of personal computers out of the market. While the Apple II constituted over 50% of the market by 1982, the other platforms shared the remaining percentage.

Infocom released Zork for the TRS-80 Model I in 1980, beginning its entry into the software entertainment industry. In the beginning, sales were slow. The TRS-80 version sold over 1500 copies, but Zork really became a hit after the Apple II version sold over 6000 copies. With two supported platforms and more on the way, Infocom began to take off.

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