BASIC (Beginners' All-purpose Symbolic Instruction Code)[1] is a family of general-purpose, high-level programming languages designed for ease of use.

Hewlett-Packard produced an entire computer line for this method of operation, introducing the HP2000 series in the late 1960s and continuing sales into the 1980s.

BASIC declined in popularity in the 1990s, as more powerful microcomputers came to market and programming languages with advanced features (such as Pascal and C) became tenable on such computers.

"[7] Moreover, the lack of any sort of immediate feedback was a key problem; the machines of the era used batch processing and took a long time to complete a run of a program.

While Kurtz was visiting MIT, John McCarthy suggested that time-sharing offered a solution; a single machine could divide up its processing time among many users, giving them the illusion of having a (slow) computer to themselves.

New Hampshire recognized the accomplishment in 2019 when it erected a highway historical marker in Hanover describing the creation of "the first user-friendly programming language".

The emergence of minicomputers during the same period, and especially low-cost microcomputers in the mid-1970s, allowed anyone to purchase and run their own systems rather than buy online time which was typically billed at dollars per minute.

These machines had small main memory, perhaps as little as 4 KB in modern terminology,[c] and lacked high-performance storage like hard drives that make compilers practical.

The first, a low-end machine in the HP 2100 series, was used to control user input and save and load their programs to tape or disk.

Despite Dijkstra's famous judgement 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",[22] BASIC was one of the few languages that was both high-level enough to be usable by those without training and small enough to fit into the microcomputers of the day, making it the de facto standard programming language on early microcomputers.

The first microcomputer version of BASIC was co-written by Bill Gates, Paul Allen and Monte Davidoff for their newly formed company, Micro-Soft.

[23] This was released by MITS in punch tape format for the Altair 8800 shortly after the machine itself,[24] 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.

How to design and implement a stripped-down version of an interpreter for the BASIC language was covered in articles by Allison in the first three quarterly issues of the People's Computer Company newsletter published in 1975 and implementations with source code published in Dr. Dobb's Journal of Tiny BASIC Calisthenics & Orthodontia: Running Light Without Overbyte.

This led to a wide variety of Tiny BASICs with added features or other improvements, with versions from Tom Pittman and Li-Chen Wang becoming particularly well known.

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 the MS code, or quickly introduced new models with it.

FutureBASIC and Chipmunk Basic meanwhile targeted the Apple Macintosh, while yab is a version of yaBasic optimized for BeOS, ZETA and Haiku.

[37] These later variations introduced many extensions, such as improved string manipulation and graphics support, access to the file system and additional data types.

[38] The addition of an integrated development environment (IDE) and electronic Help files made the products easier to work with and supported learning tools and school curriculum.

Learn BASIC Now included software disks containing the Microsoft QuickBASIC Interpreter and a programming tutorial written by Michael Halvorson and David Rygmyr.

[39] By the late 1980s, many users were using pre-made applications written by others rather than learning programming themselves, and professional developers had a wide range of advanced languages available on small computers.

The language retained some compatibility with its predecessors, such as the Dim keyword for declarations, "Gosub"/Return statements and optional line numbers which could be used to locate errors.

The latter has essentially the same power as C# and Java but with syntax that reflects the original Basic language, and also features some cross-platform capability through implementations such as Mono-Basic.

[57] The IDE, with its event-driven GUI builder, was also influential on other rapid application development tools, most notably Borland Software's Delphi for Object Pascal and its own descendants such as Lazarus.

QuickBasic is part of a series of three languages issued by Microsoft for the home and office power user and small-scale professional development; QuickC and QuickPascal are the other two.

The various Microsoft, Lotus, and Corel office suites and related products are programmable with Visual Basic in one form or another, including LotusScript, which is very similar to VBA 6.

Futurist and sci-fi writer David Brin mourned the loss of ubiquitous BASIC in a 2006 Salon article[73] as have others who first used computers during this era.

Some dialects of BASIC supported matrices and matrix operations, which can be used to solve sets of simultaneous linear algebraic equations.

New BASIC programmers on a home computer might start with a simple program, perhaps using the language's PRINT statement to display a message on the screen; a well-known and often-replicated example is Kernighan and Ritchie's "Hello, World!"

program: An infinite loop could be used to fill the display with the message: Note that the END statement is optional and has no action in most dialects of BASIC.