page_title: Early mainframe games
section_title: Background
hierarchical_section_title: Early mainframe games / Background
caption_attribution_description: An entry-level IBM System/360 system, on display at the Computer History Museum.
context_page_description: Mainframe computers 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.
context_section_description: Mainframe computers 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.
caption: A 1965 IBM System/360 Model 30 mainframe computer at the Computer History Museum
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