BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use.
The original version of BASIC was developed by John G. Kemeny (1926-1992) and Thomas E. Kurtz (1928-2024) at Dartmouth College, USA and released on the 1st of May 1964. This new language was heavily patterned on FORTRAN II, however they wanted to produce something simpler to understand that would enable students in non-scientific fields to use computers.
Wanting use of BASIC to become widespread, its designers made the compiler available free of charge. In the following years, as other entities produced their own dialects of BASIC, Kemeny and Kurtz's original BASIC version became known as Dartmouth BASIC.
The emergence of microcomputers in the mid-1970s and home computers in the early 1980s led to the development of multiple BASIC dialects, including Microsoft BASIC (MS BASIC) and CBM (Commodore) BASIC and from a UK perspective, BBC BASIC and Sinclair BASIC (also referred to as ZX BASIC).
Due to the tiny memory capacity available on many home computers, often 4 KB or less, a variety of Tiny BASIC dialects were also created. BASIC was available for almost any system of the era, and became the de facto programming language for the home computer systems of the 1980s. These computers almost always had a BASIC interpreter installed by default, often included within the machine's firmware or sometimes on a separate ROM cartridge.
BASIC declined in popularity in the 1990s with the emergence of compatible Personal Computer types produced to operate with some form of DOS (Disk Operating System) and later Microsoft's Windows operating system.
The introduction of the first microcomputers in the mid-1970s was the start of explosive growth for BASIC. It had the advantage that it was fairly well known to the young designers and computer hobbyists who took an interest in microcomputers, many of whom had seen BASIC on minicomputers or mainframes at university.
Despite Edsger Wybe Dijkstra's famous judgement of BASIC in 1975, "It is practically impossible to teach good programming to students that have had a prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration", BASIC was one of the few languages that was both high-level enough to be usable by those with minimal training and small enough to fit into the home computers of the day, making it the de facto standard programming language on early microcomputers.
The first microcomputer version of BASIC (MS-BASIC) was co-written by Bill Gates, Paul Allen and Monte Davidoff for their newly formed company, Micro-Soft. This was released by MITS in punch tape format for the Altair 8800 shortly after the machine itself, immediately cementing BASIC as the primary language of early microcomputers. Members of the Homebrew Computer Club began circulating copies of the program, causing Gates to write his Open Letter to Hobbyists, complaining about this early example of software piracy.
Partially in response to Gates's letter, and partially to make an even smaller BASIC that would run usefully on 4 kilobyte (KB) machines, Bob Albrecht urged Dennis Allison to write their own variation of the language.
Micro-Soft, by this time renamed Microsoft, ported their BASIC interpreter for the MOS 6502, which quickly become one of the most popular microprocessors of the 8-bit era. When new microcomputers began to appear, notably the "1977 trinity" of the TRS-80, Commodore PET and Apple II, they either included a version of MS BASIC, or quickly introduced new models with it. By 1978, MS BASIC had become a de facto standard. For most home computers of the 1980s a version of BASIC was included in the system ROM. Upon boot, a BASIC interpreter in direct mode was presented.
Commodore Business Machines included CBM or Commodore BASIC, based on Microsoft BASIC.
The Apple II and TRS-80 each have two versions of BASIC: a smaller introductory version with the initial releases of the machines and a Microsoft-based version introduced as interest in the platforms increased.
As new companies entered the home computing field, further versions of BASIC were produced that subtly changed BASIC to match the hardware of those machines. The Atari 8-bit computers used the 8 KB Atari BASIC which is not derived from Microsoft BASIC. Sinclair BASIC was introduced in 1980 with the Sinclair ZX80, and was later extended for the Sinclair ZX81 and the Sinclair ZX Spectrum. The BBC BASIC, developed by Acorn Computers for their BBC and Acorn models, incorporates extra structured programming keywords and floating-point features.
As the popularity of home computing (and therefore of BASIC) grew in this period, computer magazines published complete source code in BASIC for video games, utilities, and other programs. Different magazines were published featuring programs for specific computers, though some BASIC programs were considered 'universal' and could be used in machines running any variant of BASIC (usually with minor adaptations).
Many books of type-in programs were also available, and in particular, David Ahl published versions of the original 101 BASIC games converted into the Microsoft BASIC dialect and published it from Creative Computing as 'BASIC Computer Games.' The book reached the stores in 1978 and it became the first million-selling computer book.
An example of an introductory BASIC program, often seen in instruction books and manuals, is given below :
10 PRINT "Hello World"
20 GOTO 10
The keyword PRINT is a command that is most commonly used to show on-screen messages.
References:
Wikipedia.org
Retrocomputingforum.com