Early mainframe games
s are computers used primarily by businesses and academic institutions for large-scale processes. Before personal computers, first termed microcomputers, became widely available to the general public in the 1970s, the computing industry was composed of mainframe computers and the relatively smaller and cheaper minicomputer variant. During the mid to late 1960s, many early video games were programmed on these computers. Developed prior to the rise of the commercial video game industry in the early 1970s, these early mainframe games were generally written by students or employees at large corporations in a machine or assembly language that could only be understood by the specific machine or computer type they were developed on. While many of these games were lost as older computers were discontinued, some of them were ported to high-level computer languages like BASIC, had expanded versions later released for personal computers, or were recreated for bulletin board systems years later, thus influencing future games and developers.
Early computer games began to be created in the 1950s, and the steady increase in the number and abilities of computers over time led to the gradual loosening of restrictions on access to mainframe computers at academic and corporate institutions beginning in the 1960s. This in turn led to a modest proliferation of generally small, text-based games on mainframe computers, with increasing complexity towards the end of the decade. While games continued to be developed on mainframes and minicomputers through the 1970s, the rise of personal computers and the spread of high-level programming languages meant that later games were generally intended to or were capable of being run on personal computers, even when developed on a mainframe. These early games include Hamurabi, an antecedent of the strategy and city-building genres; Lunar Lander, which inspired numerous recreations in the 1970s and 1980s; Civil War, an early war simulation game; Star Trek, which was widely ported, expanded, and spread for decades after; Space Travel, which played a role in the creation of the Unix operating system; and Baseball, an early sports game and the first baseball game to allow player control during a game.
Background
s are powerful computers used primarily by large organizations for computational work, especially large-scale, multi-user processes. The term originally referred to the large cabinets called "main frames" that housed the central processing unit and main memory of early computers. Prior to the rise of personal computers, first termed microcomputers, in the 1970s, they were the primary type of computer in use, and at the beginning of the 1960s they were the only type of computer available for public purchase. Minicomputers were relatively smaller and cheaper mainframe computers prevalent in the 1960s and 1970s, though they were still not intended for personal use. One definition from 1970 required a minicomputer to cost less than US$25,000. In contrast, regular mainframes could cost more than US$1,000,000.By the end of the 1960s, mainframe computers and minicomputers were present in many academic research institutions and large companies such as Bell Labs. While the commercial video game industry did not yet exist at that point in the early history of video games and would not until the early 1970s, programmers at these companies created several small games to be played on their mainframe computers. Most of these spread only to other users of the same type of computer and therefore did not persist as older computer models were discontinued; several, however, inspired future games, or were later released in modified versions on more modern systems or languages. These early mainframe games were largely created between 1968 and 1971; while earlier games were created they were limited to small, academic audiences. Mainframe games also continued to be developed through the 1970s, but the rise of the commercial video game industry, focused on arcade video games and home video game consoles, followed by the rise of personal computers later in the decade, meant that beginning in the 1970s the audience and developers of video games began to shift away from mainframe computers or minicomputers, and the spread of general-purpose programming languages such as the BASIC programming language meant that later mainframe games could generally be run on personal computers with minimal changes, even if initially developed on a mainframe.
Early games
The very first computer games began to appear in the 1950s, starting with Bertie the Brain, a computer-based game of tic-tac-toe built by Dr. Josef Kates for the 1950 Canadian National Exhibition. While the status of these games as video games depends on the definition used, the games developed during this time period ran on the large antecedents of mainframe computers and were primarily developed for the purposes of academic research or to showcase the technological development of the computers on which they ran. Access to these computers, located almost exclusively in universities and research institutions, was restricted to academics and researchers, preventing any development of entertainment programs. Over the course of the decade, computer technology improved to include smaller, transistor-based computers on which programs could be created and run in real time, rather than operations run in batches, and computers themselves spread to more locations.By the 1960s, improvements in computing technology and the early development of relatively cheaper mainframe computers, which would later be termed minicomputers, led to the loosening of restrictions regarding programming access to the computers. At the Massachusetts Institute of Technology, access to the TX-0 experimental computer was opened to students and employees of the university. This in turn led to the development of programs that in addition to highlighting the power of the computer also contained an entertainment aspect. The games created for the TX-0 by the small programming community at MIT included Tic-Tac-Toe, which used a light pen to play a simple game of noughts and crosses against the computer, and Mouse in the Maze, which let players set up a maze for a mouse to run through. When the Digital Equipment Corporation PDP-1 computer was installed at MIT in 1961, the community built a video game to showcase its abilities, Spacewar!, which then became the first known video game to spread beyond a single computer installation as it was copied and recreated on other PDP-1 systems and later on other mainframe computers.
Over the course of the decade, computers spread to more and more companies and institutions, even as they became more powerful—by 1971, it is estimated that there were over 1000 computers with monitors, rather than the few dozen at the beginning of the 1960s. While different computers could generally not run the same programs without significant changes to the programs' code, due to differences in the physical hardware or machine languages, the expansion of the computing industry led to the creation of catalogs and user groups to share programs between different installations of the same series of computers, such as DEC's PDP line. These catalogs and groups, such as the IBM program catalog and the Digital Equipment Computer Users' Society, shared small games as well as programs, including, for example, "BBC Vik The Baseball Demonstrator" by John Burgeson and "Three Dimensional Tic-Tack-Toe" in the April 1962 IBM catalog, and dice games and question and answer games in the DECUS newsletter. The Sumerian Game for the IBM 7090, a strategy video game of land and resource management, was the first educational game for children. Mainframe games were developed outside of the IBM and DEC communities as well, such as the 1962 Polish Marienbad for the Odra 1003, and blackjack, hangman, and tic-tac-toe on the United States Air Force and RAND's JOSS.
By the latter half of the 1960s, higher-level programming languages such as BASIC which were able to be run on multiple types of computers further increased the reach of games developed at any given location. While most games were limited to text-based designs, rather than visual graphics like Spacewar, these games became more complicated as they reached more players, such as baseball and basketball simulation games. The November 1969 DECUS catalog listed 37 games and demos including Spacewar and The Sumer Game, compared to 58 scientific and engineering applications, the most common intended purpose of a minicomputer. Access to the computers themselves was also extended to more people by systems such as the Dartmouth Time-Sharing System, which connected several thousand users through many remote terminals to a central mainframe computer. By the 1967–68 school year the DTSS library of 500 programs for the system included, John G. Kemeny and Thomas E. Kurtz wrote, "many games". Over a quarter of the system's usage was for casual or entertainment purposes, which Kemeny and Kurtz welcomed as helping users to become familiar with and not fear the computer. They noted that "we have lost many a distinguished visitor for several hours while he quarterbacked the Dartmouth football team in a highly realistic simulated game". By 1972 the football simulation had become a multiplayer video game, supporting head-to-head play.
Mainframe games were also played and watched by people outside of college campuses. In 1968, Cornell University School of Hotel Administration funded the development of two business games: Cornell Hotel Administration Simulation Exercise and Cornell Restaurant Administration Simulation Exercise. The former was a backronym, having been developed by Prof. Robert Chase and his students. Notably the restaurant game featured competitive play, with teams of players managing competing restaurants. The games were made playable for attendees at national conventions of the American Hotel & Motel Association and the Club Managers Association of America in 1969. On Christmas Eve, 1970, the BBC television program Tomorrow's World broadcast a mainframe computer racing game played between TV presenter Raymond Baxter and British two-time Formula One world champion Graham Hill on their Christmas special. The game was written by IBM-employee, Ray Bradshaw, using CALL/360 and required two data center operators to input the instructions. "The race was run to show that computers could be fun."