GW-BASIC is a dialect of the
BASIC
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 was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College ...
programming language
A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language.
The description of a programming ...
developed by
Microsoft
Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...
from
IBM BASICA. Functionally identical to BASICA, its
BASIC interpreter
A BASIC interpreter is an interpreter that enables users to enter and run programs in the BASIC language and was, for the first part of the microcomputer era, the default application that computers would launch. Users were expected to use the BAS ...
is a fully self-contained executable and does not need the
Cassette BASIC
The IBM Personal Computer Basic, commonly shortened to IBM BASIC, is a programming language first released by IBM with the IBM Personal Computer, Model 5150 (IBM PC) in 1981. IBM released four different versions of the Microsoft BASIC interpre ...
ROM found in the original
IBM PC
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team ...
. It was bundled with
MS-DOS
MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few ope ...
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
s on
IBM PC compatible
Hawaii
IBM PC compatible computers are similar to the original IBM PC, XT, and AT, all from computer giant IBM, that are able to use the same software and expansion cards. Such computers were referred to as PC clones, IBM clones or IBM PC cl ...
s by Microsoft.
The language is suitable for simple games, business programs and the like. Since it was included with most versions of MS-DOS, it was also a low-cost way for many aspiring
programmer
A computer programmer, sometimes referred to as a software developer, a software engineer, a programmer or a coder, is a person who creates computer programs — often for larger computer software.
A programmer is someone who writes/creates ...
s to learn the fundamentals of
computer programming
Computer programming is the process of performing a particular computation (or more generally, accomplishing a specific computing result), usually by designing and building an executable computer program. Programming involves tasks such as ana ...
. Microsoft also sold a BASIC
compiler
In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs that ...
, BASCOM, compatible with GW-BASIC, for programs needing more speed.
According to Mark Jones Lorenzo, given the scope of the language, "GW-BASIC is arguably the ''
ne plus ultra
NE, Ne or ne may refer to:
Arts and entertainment
* Neutral Evil, an alignment in the American role-playing game ''Dungeons & Dragons''
* New Edition, an American vocal group
* Nicomachean Ethics, a collection of ten books by Greek philosopher Ar ...
'' of Microsoft's family of line-numbered BASICs stretching back to
Altair BASIC
Altair BASIC is a discontinued interpreter for the BASIC programming language that ran on the MITS Altair 8800 and subsequent S-100 bus computers. It was Microsoft's first product (as Micro-Soft), distributed by MITS under a contract. Altair BASI ...
and perhaps even of line-numbered BASIC in general."
With the release of MS-DOS 5.0, GW-BASIC's place was taken by
QBasic
QBasic is an integrated development environment (IDE) and interpreter for a variety of dialects of BASIC which are based on QuickBASIC. Code entered into the IDE is compiled to an intermediate representation (IR), and this IR is immediately e ...
, a slightly abridged version of the interpreter part of the separately available
QuickBASIC
Microsoft QuickBASIC (also QB) is an Integrated Development Environment (or IDE) and compiler for the BASIC programming language that was developed by Microsoft. QuickBASIC runs mainly on DOS, though there was also a short-lived version for the c ...
interpreter and compiler package.
On May 21, 2020, Microsoft released the
8088 assembler source code for GW-BASIC 1.0 on
GitHub
GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, continuous ...
under the
MIT License
The MIT License is a permissive free software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts only very limited restriction on reuse and has, therefore, high license comp ...
.
Features
IBM BASICA and GW-BASIC are largely ports of
MBASIC
MBASIC is the Microsoft BASIC implementation of BASIC for the CP/M operating system. MBASIC is a descendant of the original Altair BASIC interpreters that were among Microsoft's first products. MBASIC was one of the two versions of BASIC bundled w ...
version 5.x, but with added features specifically for the IBM PC hardware. Common features of BASIC-80 5.x and BASICA/GW-BASIC include:
*
WHILE...WEND
loops
* Variable names of up to 40 characters
*
OPTION BASE
statement to set the starting index of array variables as either 0 or 1
* Dynamic string space allocation
*
LINE INPUT
, which allowed field-separator characters like comma to be ignored
*
CALL
statement for executing machine-language routines
*
CHAIN
and
MERGE
commands
* Ability to save programs in either tokenized binary format or ASCII text
The ability to "crunch" program lines by omitting spaces, a common feature of earlier Microsoft BASIC implementations, was removed from BASIC-80 5.x and BASICA/GWBASIC.
BASIC-80 programs not using
PEEK
/
POKE
statements run under GW-BASIC. BASICA adds many features for the IBM PC such as sound, graphics, and memory commands. Features not present in BASIC-80 include the ability to execute the
RND
function with no parameters and the ability to also save programs in a "protected" format, preventing them from being
LIST
ed. BASICA also allows double-precision numbers to be used with mathematical and trigonometric functions such as
COS
,
SIN
, and
ATN
, which wasn't allowed in 8-bit versions of BASIC. This feature was normally not enabled and required the optional parameter
/D
at startup, i.e.,
GWBASIC /D
. BASIC's memory footprint was slightly increased if it was used.
Microsoft did not offer a generic version of MS-DOS until v3.20 in 1986; before then, all variants of the operating system were OEM versions. Depending on the OEM, BASIC was distributed as either BASICA.EXE or GWBASIC.EXE. The former should not be confused with IBM BASICA, which always came as a
COM file
A COM file is a type of simple executable file. On the Digital Equipment Corporation (DEC) VAX operating systems of the 1970s, .COM was used as a filename extension for text files containing commands to be issued to the operating system (simi ...
. Some variants of BASIC has extra features to support a particular machine. For example, the AT&T and Tandy versions of DOS include a special GW-BASIC that supports their enhanced sound and graphics capabilities.
The initial version of GW-BASIC is the one included with Compaq DOS 1.13, released with the Compaq Portable in 1983, and was analogous to IBM BASICA 1.10. It uses the
CP/M
CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/ 85-based microcomputers by Gary Kildall of Digital Research, Inc. Initial ...
-derived file control blocks for disk access and does not support subdirectories. Later versions support subdirectories, improved graphics, and other capabilities.
GW-BASIC 3.20 (1986) adds
EGA graphics support (no version of BASICA or GW-BASIC had
VGA
Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the PC industry within three years. The term can no ...
support) and is the last major new version released before it was superseded by
QBasic
QBasic is an integrated development environment (IDE) and interpreter for a variety of dialects of BASIC which are based on QuickBASIC. Code entered into the IDE is compiled to an intermediate representation (IR), and this IR is immediately e ...
.
Buyers of
Hercules Graphics Card The Hercules Graphics Card (HGC) is a computer graphics controller made by Hercules Computer Technology, Inc. that combines IBM's text-only MDA display standard with a bitmapped graphics mode. This allows the HGC to offer both high-quality text an ...
s received a special version of GW-BASIC on the card's utility disk that is called HBASIC, which adds support for its 720×348 monochrome graphics. Other versions of BASICA/GW-BASIC do not support Hercules graphics and can only display graphics on that card through the use of third-party
CGA emulation, such as SIMCGA.
GW-BASIC has a
command-line
A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...
-based
integrated development environment
An integrated development environment (IDE) is a software application that provides comprehensive facilities to computer programmers for software development. An IDE normally consists of at least a source code editor, build automation tools a ...
(IDE) based on
Dartmouth BASIC
Dartmouth BASIC is the original version of the BASIC programming language. It was designed by two professors at Dartmouth College, John G. Kemeny and Thomas E. Kurtz. With the underlying Dartmouth Time Sharing System (DTSS), it offered an inter ...
. Using the cursor movement keys, any line displayed on the screen can be edited. It also includes
function key
A function key is a key on a computer or terminal keyboard that can be programmed so as to cause an operating system command interpreter or application program to perform certain actions, a form of soft key. On some keyboards/computers, function ...
shortcuts at the bottom of the screen. Like other early
microcomputer
A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (PC ...
versions of BASIC, GW-BASIC lacks many of the structures needed for
structured programming
Structured programming is a programming paradigm aimed at improving the clarity, quality, and development time of a computer program by making extensive use of the structured control flow constructs of selection ( if/then/else) and repetition ( ...
, such as local variables. GW-BASIC programs executed relatively slowly because it was an
interpreted language
In computer science, an interpreter is a computer program that directly executes instructions written in a programming or scripting language, without requiring them previously to have been compiled into a machine language program. An interprete ...
. All program lines must be numbered; all non-numbered lines are considered to be commands in
direct mode
In computing, direct or immediate mode in an interactive programming system is the immediate execution of commands, statements, or expressions. In many interactive systems, most of these can both be included in programs or executed directly in ...
to be executed immediately. Program source files are normally saved in binary compressed format with
tokens replacing keywords, with an option to save in
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of ...
text form.
The GW-BASIC command-line environment has commands to
RUN
,
LOAD
,
SAVE
,
LIST
the current program, or quit to the operating
SYSTEM
; these commands can also be used as program statements. There is little support for
structured programming
Structured programming is a programming paradigm aimed at improving the clarity, quality, and development time of a computer program by making extensive use of the structured control flow constructs of selection ( if/then/else) and repetition ( ...
in GW-BASIC. All
IF
/
THEN
/
ELSE
conditional statements must be written on one line, although
WHILE
/
WEND
statements may group multiple lines.
Functions can only be defined using the single line
DEF FN A user-defined function (UDF) is a function provided by the user of a program or environment, in a context where the usual assumption is that functions are built into the program or environment. UDFs are usually written for the requirement of its cr ...
f(x)=
statement (e.g.,
DEF FNLOG(base,number)=LOG(number)/LOG(base)
). The data type of
variables can be specified with a character at the end of the variable name:
A$
is a
string of characters,
A%
is an
integer
An integer is the number zero (), a positive natural number (, , , etc.) or a negative integer with a minus sign (−1, −2, −3, etc.). The negative numbers are the additive inverses of the corresponding positive numbers. In the language ...
, etc. Groups of variables can also be set to default types based on the initial letter of their name by use of the
DEFINT
,
DEFSTR
, etc., statements. The default type for undeclared variables not identified by such typing statements is single-precision
floating-point
In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can b ...
(
32-bit MBF
3 (three) is a number, numeral and digit. It is the natural number following 2 and preceding 4, and is the smallest odd prime number and the only prime preceding a square number. It has religious or cultural significance in many societie ...
).
GW-BASIC allows use of
joystick
A joystick, sometimes called a flight stick, is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. A joystick, also known as the control column, is the principal cont ...
and
light pen
A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's cathode-ray tube (CRT) display.
It allows the user to point to displayed objects or draw on the screen in a similar way to a tou ...
input devices. GW-BASIC can read from and write to files and
COM ports; it can also do event trapping for ports. Since the cassette tape port interface of the original IBM PC was never implemented on compatibles, cassette operations are not supported. GW-BASIC can play simple music using the
PLAY
statement, needing a string of notes represented in a
music macro language
Music Macro Language (MML) is a music description language used in sequencing music on computer and video game systems.
Background
Early automatic music generation functions were used in arcade games, which used many computer sounds. An example ...
, e.g.,
PLAY "edcdeeL2edfedL4c"
. More
low-level control is possible with the
SOUND
statement, which takes the arguments of a
frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...
in
hertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that on ...
and a length in clock ticks for the standard internal
PC speaker in IBM machines. Consequently, sound is limited to single channel beeps and whistles as befits a "business" machine. Home-based PCs like the
Tandy 1000 allow up to three channels of sound for the
SOUND
and
PLAY
commands.
Name
There are several theories on what the initials "GW" stand for.
Greg Whitten, an early
Microsoft
Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...
employee who developed the standards in the company's BASIC compiler line, says that
Bill Gates
William Henry Gates III (born October 28, 1955) is an American business magnate and philanthropist. He is a co-founder of Microsoft, along with his late childhood friend Paul Allen. During his career at Microsoft, Gates held the positions ...
picked the name GW-BASIC. Whitten refers to it as ''Gee-Whiz'' BASIC and is unsure whether Gates named the program after him.
The ''Microsoft User Manual'' from
Microsoft Press
Microsoft Press is the publishing arm of Microsoft
Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the ...
also refers to it by this name. It may have also been
nickname
A nickname is a substitute for the proper name of a familiar person, place or thing. Commonly used to express affection, a form of endearment, and sometimes amusement, it can also be used to express defamation of character. As a concept, it is ...
d ''Gee-Whiz'' because of its numerous
graphics
Graphics () are visual images or designs on some surface, such as a wall, canvas, screen, paper, or stone, to inform, illustrate, or entertain. In contemporary usage, it includes a pictorial representation of data, as in design and manufacture ...
commands.
Other common theories as to the initials' origins include "Graphics and Windows", "
Gates, William" (Microsoft's president at the time), or "Gates–Whitten" (the two main designers of the program).
See also
*
Microsoft Binary Format
In computing, Microsoft Binary Format (MBF) is a format for floating-point numbers which was used in Microsoft's BASIC language products, including MBASIC, GW-BASIC and QuickBASIC prior to version 4.00.
There are two main versions of the format ...
(MBF)
References
External links
GW-BASIC source code on GitHub*
regarding BASIC, with timeline dates for DOS, Windows and BASIC dialects
GW-BASIC– A resource for GW-BASIC, gathered from various sources.
{{DEFAULTSORT:Gw-Basic
Discontinued Microsoft BASICs
Programming languages created in 1983
BASIC interpreters
BASIC programming language family
Software using the MIT license
Assembly language software
Formerly proprietary software
Microsoft free software
Microsoft programming languages