CAL

CAL, short for Conversational Algebraic Language, was a programming language and system designed and developed by Butler Lampson at Berkeley in 1967 for the SDS 940 mainframe computer. CAL is a version of the seminal JOSS language with several cleanups and new features to take advantage of the SDS platform. The Berkeley SDS was used for the development of the Tymshare commercial time-sharing platform and an improved version of CAL was offered as a programming environment to its customers in 1969. Although CAL saw "almost no use", it had a lasting impact by influencing the design of Tymshare SUPER BASIC which copied a number of its features. Some of those features, in turn, appeared in BASIC-PLUS on the PDP-11, which is the direct ancestor of Microsoft BASIC. Description Basic concepts JOSS had been designed to be used by non-programmers in the US Air Force and within Rand Corporation, and to aid with that, Rand designed to custom computer terminals that were easier to set up and use. These terminals, based on the IBM Selectric typewriter, also included a custom character set that implemented common mathematical symbols like and .