Development
Adventure was designed and programmed by Atari employee Warren Robinett and published by Atari, Inc. At the time, Atari programmers were generally given full control on the creative direction and development cycle for their games; to stay productive, this required them to begin planning their next game as they neared completion of their current one.[4] Robinett was finishing his work on Slot Racers when he was given an opportunity to visit the Stanford Artificial Intelligence Laboratory by Julius Smith, one of several friends he was sharing a house with. There, he was introduced to the 1977 version of the computer text game Colossal Cave Adventure, created by Will Crowther and modified by Don Woods. After playing the game for several hours, he was inspired to create a graphical version.[5][4][6]
Robinett began designing his graphics-based game with the help of a Hewlett-Packard 1611A logic analyzer (a debugging tool) around May to June 1978.[6] He was soon aware that memory use was critical because Atari 2600 cartridge ROMs had only 4096 bytes (4 KB),[3] and the system had 128 bytes of RAM for program variables. In contrast, Colossal Cave Adventure used hundreds of kilobytes of memory on a large computer.[6] The final game used nearly all of the available memory (including 5% of the cartridge storage for Robinett's Easter egg), with 15 unused bytes from the ROM capacity.[6] Robinett credits Ken Thompson, his professor at University of California, Berkeley, with teaching him the skills needed to use the limited memory efficiently. Thompson had required his students to learn the C programming language that he had invented at AT&T, and Robinett carried C techniques into assembly language.
Robinett first identified ways to translate the elements of Colossal Cave Adventure into simple, easily recognizable graphics that the player interacted with directly, replacing text-based commands with joystick controls.[4][6] Due to the system's low-resolution pixels, Robinett noted the dragons look more like ducks.[6] Robinett developed workarounds for various technical limitations of the Atari 2600, which has only one playfield and five memory-mapped registers available to represent moving objects. Only two of these registers are capable of representing more complex sprites, so he used those for objects and creatures within the game. He used the register originally designated for the ball in games such as Pong to represent the player's avatar. Finally, he used the registers assigned for missiles, such as the bullets in Combat, for additional walls in the playing field, so as to represent different rooms within the game using the same playfield.[4] Another hardware limitation forces the left and right sides of nearly every screen to be mirrored, which fostered the creation of the game's confusing mazes.
Robinett overcame these limitations to introduce concepts novel to video games. He constructed thirty different rooms, whereas most games of the time presented only a single screen.[6] Furthermore, off-screen objects such as the bat continued to move according to their programming behavior.[6]
In addition to the technical limitations, Robinett had struggled with Atari's management over the game. Around the time of Adventure's development, Atari, then owned by Warner Communications, had hired Ray Kassar as general manager of their Consumer Division, and he was later promoted to president and CEO of Atari in December 1978. Kassar interacted with the programmers rarely and generally treated their contributions with indifference.[8] Robinett was initially discouraged from working on Adventure by his supervisor, George Simcock, who said the ambitious game could not be done on Atari 2600 based on knowing how much memory Colossal Cave Adventure uses.[4][9] When Robinett developed a working prototype within one month, Atari's management team was impressed, encouraging him to continue the game.[4] The management later tried to convince Robinett to make it a tie-in work for the upcoming film Superman (1978), which was owned by Warner Communication, but Robinett remained committed to his initial idea.[6] Instead, Atari developer John Dunn agreed to take Robinett's prototype source code to make the
A second prototype was completed near the end of 1978, with only about eight rooms, a single dragon, and two objects. Robinett recognized that it demonstrated his design goals but was boring. He put the game aside for a few months and came back with additional ideas, finishing it by June 1979.[4] Three of these changes were the dragon being able to eat the avatar, the ability to "resurrect" the avatar, and the addition of the sword object with which to kill the dragon. Robinett found that the possibilities that arose from this combination of elements improved the excitement of the game, and he subsequently made three dragons, reusing the same source code for the behavior of all three. The magnet was created to work around a potential situation where the player could irretrievably drop an object into a wall space.[4]
To develop the game's plot, Robinett worked with Steve Harding, the author for nearly all Atari 2600 game manuals at that time. Harding developed most of the plot after playing the game, with Robinett revising elements where he saw fit. Robinett invented names for all three dragons and used a friend's suggestion for naming the bat "Knubberrub", although the bat's name never made it into the game's official documentation.[4]
Robinett submitted the source code for Adventure to Atari management in June 1979[11] and soon left Atari.[6][12] Atari released the game in March 1980.[13][14]
