SuperBASIC is an advanced variant of the BASIC programming language with many structured programming additions. It was developed at Sinclair Research by Jan Jones during the early 1980s.
106-637: Originally SuperBASIC was intended as the BASIC interpreter for a home computer code-named SuperSpectrum , then under development. This project was later cancelled; however, SuperBASIC was subsequently included in the ROM firmware of the Sinclair QL microcomputer (announced in January 1984), also serving as the command line interpreter for the QL's QDOS operating system . It
212-502: A PDP-10 time-sharing computer. Allen adapted this emulator based on the Altair programmer guide, and they developed and tested the interpreter on Harvard's PDP-10. When Harvard stopped their use of this system, Gates and Allen bought computer time from a timesharing service in Boston to complete their BASIC program debugging. Gates claimed, in his Open Letter to Hobbyists in 1976, the value of
318-547: A syntax chart for the language. He did not know that HP's BASIC was very different from the DEC BASIC variety used in 101 Games . The two languages differed principally in terms of string handling and control structures. Data General Business Basic , an integer-only implementation, was the inspiration for Atari BASIC. In contrast, Dennis Allison , a member of the Computer Science faculty at Stanford University , wrote
424-428: A system call to perform a block I/O write operation, then the system call might execute the following instructions: While the writing takes place, the operating system will context switch to other processes as normal. When the device finishes writing, the device will interrupt the currently running process by asserting an interrupt request . The device will also place an integer onto the data bus. Upon accepting
530-595: A web browser . In 2014, Robin H. Edwards released Arduino BASIC for the Arduino , and now a widely forked implementation. Another implementation using the same name was adapted from Palo Alto Tiny BASIC in 1984 by Gordon Brandly for his 68000 Tiny BASIC, later ported to C by Mike Field. Many BASIC interpreters are now available for smartphones and tablets via the Apple App Store , or Google Play store for Android. Today, coding BASIC interpreters has become part of
636-408: A BASIC compiler (not an interpreter) as one of its primary selling points. Other companies in the emerging field quickly followed suit. By the early 1970s, BASIC was largely universal on general-purpose mainframe computers. BASIC, as a streamlined language designed with integrated line editing in mind, was naturally suited to porting to the minicomputer market, which was emerging at the same time as
742-404: A BASIC interpreter could be. Because RAM were sold as 4 KB chips, Altair BASIC was initially packaged in separate editions for 4K, 8K, and 12K; this carried over to ROM chips, as manufacturers would decide how many ROM chips they could fit in their design, given price goals and other constraints. The first implementation of BASIC, Dartmouth BASIC , was a compiler. Generally, compilers examine
848-409: A compiler, the entire source code is converted during what appears to the user as a single operation, whereas an interpreter converts and runs the source one statement at a time. The resulting machine code is executed, rather than output, and then that code is then discarded and the process repeats with the next statement. This dispenses with the need for some form of secondary storage while an executable
954-645: A computer even if they are not compatible with the base operating system. A library operating system (libOS) is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with a single application and configuration code to construct a unikernel : a specialized (only the absolute necessary pieces of code are extracted from libraries and bound together ), single address space , machine image that can be deployed to cloud or embedded environments. The operating system code and application code are not executed in separated protection domains (there
1060-571: A development of MULTICS for a single user. Because UNIX's source code was available, it became the basis of other, incompatible operating systems, of which the most successful were AT&T 's System V and the University of California 's Berkeley Software Distribution (BSD). To increase compatibility, the IEEE released the POSIX standard for operating system application programming interfaces (APIs), which
1166-654: A focus on multimedia: STOS BASIC for the Atari ST , in 1988, and AMOS BASIC for the Amiga , in 1990. In May 1991, Microsoft released Visual Basic , a third-generation event-driven programming language known for its Component Object Model (COM) programming model. Visual Basic supported the rapid application development (RAD) of graphical user interface (GUI) applications, access to databases using Data Access Objects , Remote Data Objects , or ActiveX Data Objects , and creation of ActiveX controls and objects. Visual Basic
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#17328548654891272-526: A game creation system for Microsoft Windows , with accompanying IDE and development tools. In 2001, SmallBASIC was released for the Palm PDA . Another BASIC interpreter for Palm was HotPaw BASIC, an offshoot of Chipmunk Basic . In 2002, Emmanuel Chailloux, Pascal Manoury and Bruno Pagano published a Tiny BASIC as an example of developing applications with Objective Caml . In 2011, Microsoft released Small Basic (distinct from SmallBASIC), together with
1378-484: A large legal settlement was paid. In the twenty-first century, Windows continues to be popular on personal computers but has less market share of servers. UNIX operating systems, especially Linux, are the most popular on enterprise systems and servers but are also used on mobile devices and many other computer systems. On mobile devices, Symbian OS was dominant at first, being usurped by BlackBerry OS (introduced 2002) and iOS for iPhones (from 2007). Later on,
1484-442: A library with no protection between applications, such as eCos . A hypervisor is an operating system that runs a virtual machine . The virtual machine is unaware that it is an application and operates as if it had its own hardware. Virtual machines can be paused, saved, and resumed, making them useful for operating systems research, development, and debugging. They also enhance portability by enabling applications to be run on
1590-447: A malformed machine instruction . However, the most common error conditions are division by zero and accessing an invalid memory address . Users can send messages to the kernel to modify the behavior of a currently running process. For example, in the command-line environment , pressing the interrupt character (usually Control-C ) might terminate the currently running process. To generate software interrupts for x86 CPUs,
1696-455: A particular application's memory is stored, or even whether or not it has been allocated yet. In modern operating systems, memory which is accessed less frequently can be temporarily stored on a disk or other media to make that space available for use by other programs. This is called swapping , as an area of memory can be used by multiple programs, and what that memory area contains can be swapped or exchanged on demand. Virtual memory provides
1802-503: A program does not interfere with memory already in use by another program. Since programs time share, each program must have independent access to memory. Cooperative memory management, used by many early operating systems, assumes that all programs make voluntary use of the kernel 's memory manager, and do not exceed their allocated memory. This system of memory management is almost never seen any more, since programs often contain bugs which can cause them to exceed their allocated memory. If
1908-408: A program fails, it may cause memory used by one or more other programs to be affected or overwritten. Malicious programs or viruses may purposefully alter another program's memory, or may affect the operation of the operating system itself. With cooperative memory management, it takes only one misbehaved program to crash the system. Memory protection enables the kernel to limit a process' access to
2014-440: A program tries to access memory that is not accessible memory, but nonetheless has been allocated to it, the kernel is interrupted (see § Memory management ) . This kind of interrupt is typically a page fault . When the kernel detects a page fault it generally adjusts the virtual memory range of the program which triggered it, granting it access to the memory requested. This gives the kernel discretionary power over where
2120-467: A significant amount of CPU time. Direct memory access (DMA) is an architecture feature to allow devices to bypass the CPU and access main memory directly. (Separate from the architecture, a device may perform direct memory access to and from main memory either directly or via a bus.) When a computer user types a key on the keyboard, typically the character appears immediately on the screen. Likewise, when
2226-402: A specific moment in time. Hard real-time systems require exact timing and are common in manufacturing , avionics , military, and other similar uses. With soft real-time systems, the occasional missed event is acceptable; this category often includes audio or multimedia systems, as well as smartphones. In order for hard real-time systems be sufficiently exact in their timing, often they are just
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#17328548654892332-528: A specification for a simple version of the language. Allison was urged to create the standard by Bob Albrecht of the Homebrew Computer Club , who had seen BASIC on minicomputers and felt it would be the perfect match for new machines like the Altair. Allison's proposed design only used integer arithmetic and did not support arrays or string manipulation. The goal was for the program to fit in 2 to 3 kilobytes of memory. The overall design for Tiny BASIC
2438-404: A system that wrote out the source, compiled it, and then ran the result would have taken minutes. Because of these constraints, interpreters proliferated. Interpreters ultimately perform the same basic tasks as compilers, reading the source code and converting that into executable instructions calling runtime functions. The primary difference is when they perform the various tasks. In the case of
2544-488: A teaching curriculum and an introductory guide., designed to help students who have learnt visual programming languages such as Scratch learn text-based programming. The associated IDE provides a simplified programming environment with functionality such as syntax highlighting , intelligent code completion , and in-editor documentation access. The language has only 14 keywords. In 2019, Microsoft announced Small Basic Online (SBO), allowing students to run programs from
2650-409: A typical mainframe might have on the order of 64 KB. On a timesharing system, the case for most 1960s BASICs, that memory was shared among many users. In order to make a compiler work, the systems had to have some form of high-performance secondary storage , typically a hard drive . Program editing took place in a dedicated environment that wrote the user's source code to a temporary file. When
2756-417: A user moves a mouse , the cursor immediately moves across the screen. Each keystroke and mouse movement generates an interrupt called Interrupt-driven I/O . An interrupt-driven I/O occurs when a process causes an interrupt for every character or word transmitted. Devices such as hard disk drives , solid-state drives , and magnetic tape drives can transfer data at a rate high enough that interrupting
2862-453: A variation of the classic reader/writer problem . The writer receives a pipe from the shell for its output to be sent to the reader's input stream. The command-line syntax is alpha | bravo . alpha will write to the pipe when its computation is ready and then sleep in the wait queue. bravo will then be moved to the ready queue and soon will read from its input stream. The kernel will generate software interrupts to coordinate
2968-500: A wide variety of Tiny BASICs with added features or other improvements, with well-known versions from Tom Pittman and Li-Chen Wang , both members of the Homebrew Computer Club. Tiny BASIC was published openly and Wang coined the term "copyleft" to encourage others to copy his source code. Hobbyists and professionals created their own implementations, making Tiny BASIC an example of a free software project that existed before
3074-418: Is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers . In the personal computer market, as of September 2024 , Microsoft Windows holds a dominant market share of around 73%. macOS by Apple Inc. is in second place (15%), Linux is in third place (5%), and ChromeOS
3180-562: Is remote direct memory access , which enables each CPU to access memory belonging to other CPUs. Multicomputer operating systems often support remote procedure calls where a CPU can call a procedure on another CPU, or distributed shared memory , in which the operating system uses virtualization to generate shared memory that does not physically exist. A distributed system is a group of distinct, networked computers—each of which might have their own operating system and file system. Unlike multicomputers, they may be dispersed anywhere in
3286-484: Is a change away from the currently running process. Similarly, both hardware and software interrupts execute an interrupt service routine . Software interrupts may be normally occurring events. It is expected that a time slice will occur, so the kernel will have to perform a context switch . A computer program may set a timer to go off after a few seconds in case too much data causes an algorithm to take too long. Software interrupts may be error conditions, such as
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3392-641: Is a compatible superset of Atari BASIC, developed by Frank Ostrowski and published in the December 1985 issue of German computer magazine Happy Computer , making it one of the last interpreters published as a type-in program . The language included a compiler in addition to the interpreter and featured structured programming commands. Several modified versions working with different DOS systems were released by other authors. In France, François Lionet and Constantin Sotiropoulos developed two BASIC interpreters with
3498-456: Is a major challenge, but it eliminates the need for secondary storage and was the only practical solution for early minicomputers and most of the history of the home computer revolution. Language design for the first interpreters often simply involved referencing other implementations. For instance, Wozniak's references for BASIC were an HP BASIC manual and a copy of 101 BASIC Computer Games . Based on these sources, Wozniak began sketching out
3604-447: Is being built. The primary disadvantage is that you can no longer split the different parts of the overall process apart - the code needed to convert the source into machine operations has to be loaded into memory along with the runtime needed to perform it, and in most cases, the source code editor as well. Producing a language with all of these components that can fit into a small amount of memory and still has room for user's source code
3710-553: Is common in computer language grammar notation, the vertical bar (" | ") distinguishes alternatives, as does being listed on separate lines. The symbol " CR " denotes a carriage return . This syntax, as simple as it was, added one innovation: GOTO and GOSUB could take an expression rather than a line number, providing an assigned GOTO rather than the switch statement of the ON-GOTO/GOSUB structure more typical of BASIC. Sinclair BASIC used as its language definition
3816-422: Is difficult to define, but has been called "the layer of software that manages a computer's resources for its users and their applications ". Operating systems include the software that is always running, called a kernel —but can include other software as well. The two other types of programs that can run on a computer are system programs —which are associated with the operating system, but may not be part of
3922-896: Is in fourth place (2%). In the mobile sector (including smartphones and tablets ), as of September 2023 , Android's share is 68.92%, followed by Apple's iOS and iPadOS with 30.42%, and other operating systems with .66%. Linux distributions are dominant in the server and supercomputing sectors. Other specialized classes of operating systems (special-purpose operating systems), such as embedded and real-time systems, exist for many applications. Security-focused operating systems also exist. Some operating systems have low system requirements (e.g. light-weight Linux distribution ). Others may have higher system requirements. Some operating systems require installation or may come pre-installed with purchased computers ( OEM -installation), whereas others may run directly from media (i.e. live CD ) or flash memory (i.e. USB stick). An operating system
4028-443: Is only a single application running, at least conceptually, so there is no need to prevent interference between applications) and OS services are accessed via simple library calls (potentially inlining them based on compiler thresholds), without the usual overhead of context switches , in a way similarly to embedded and real-time OSes. Note that this overhead is not negligible: to the direct cost of mode switching it's necessary to add
4134-499: Is supported by most UNIX systems. MINIX was a stripped-down version of UNIX, developed in 1987 for educational uses, that inspired the commercially available, free software Linux . Since 2008, MINIX is used in controllers of most Intel microchips , while Linux is widespread in data centers and Android smartphones. The invention of large scale integration enabled the production of personal computers (initially called microcomputers ) from around 1980. For around five years,
4240-473: Is that they do not load user-installed software. Consequently, they do not need protection between different applications, enabling simpler designs. Very small operating systems might run in less than 10 kilobytes , and the smallest are for smart cards . Examples include Embedded Linux , QNX , VxWorks , and the extra-small systems RIOT and TinyOS . A real-time operating system is an operating system that guarantees to process events or data by or at
4346-435: Is the part of the operating system that provides protection between different applications and users. This protection is key to improving reliability by keeping errors isolated to one program, as well as security by limiting the power of malicious software and protecting private data, and ensuring that one program cannot monopolize the computer's resources. Most operating systems have two modes of operation: in user mode ,
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4452-543: The Altair 8800 shortly after the machine itself, showcasing BASIC as the primary language for early microcomputers. In March 1975, Steve Wozniak attended the first meeting of the Homebrew Computer Club and began formulating the design of his own computer. Club members were excited by Altair BASIC. Wozniak concluded that his machine would have to have a BASIC of its own. At the time he was working at Hewlett Packard and used their minicomputer dialect, HP Time-Shared BASIC , as
4558-558: The Apple I ). During the Altair period, BASIC interpreters were sold separately, becoming the first software sold to individuals rather than to organizations; Apple BASIC was Apple's first software product. After the MITS Altair 8800 , microcomputers were expected to ship bundled with BASIC interpreters of their own (e.g., the Apple II , which had multiple implementations of BASIC). A backlash against
4664-569: The BBC Micro and Locomotive BASIC for the Amstrad CPC , both supporting commands for an ISAM indexed file system. In 1985, MetaComCo released ABasiC for the Amiga and ST BASIC for the Atari ST . In 1978, David Lien published the first edition of The BASIC Handbook: An Encyclopedia of the BASIC Computer Language , documenting keywords across over 78 different computers. By 1981,
4770-535: The CP/M (Control Program for Microcomputers) was the most popular operating system for microcomputers. Later, IBM bought the DOS (Disk Operating System) from Microsoft . After modifications requested by IBM, the resulting system was called MS-DOS (MicroSoft Disk Operating System) and was widely used on IBM microcomputers. Later versions increased their sophistication, in part by borrowing features from UNIX. Apple 's Macintosh
4876-528: The Data General Nova . One holdout was Digital Equipment Corporation (DEC), the leading minicomputer vendor. They had released a new language known as FOCAL , based on the earlier JOSS developed on a DEC machine at the Stanford Research Institute in the early 1960s. JOSS was similar to BASIC in many respects, and FOCAL was a version designed to run in very small memory systems, notably
4982-447: The IBM PC team, said, "IBM has an excellent BASIC--it's well received, runs fast on mainframe computers, and it's a lot more functional than micro-computer BASICs... But [its] number of users were infinitesimal compared to the number of Microsoft BASIC users. Microsoft BASIC had hundreds of thousands of users around the world. How are you going to argue with that?" (See Microsoft BASIC for
5088-496: The INT assembly language instruction is available. The syntax is INT X , where X is the offset number (in hexadecimal format) to the interrupt vector table . To generate software interrupts in Unix-like operating systems, the kill(pid,signum) system call will send a signal to another process. pid is the process identifier of the receiving process. signum is
5194-566: The OCaml Tiny BASIC . Initially, interpreters were either bundled with computer hardware or developed as a custom service, before an industry producing independently packaged software for organizations came about in the late 1960s. BASIC interpreters were first sold separately from microcomputers, then built-in, before becoming sold as applications again in the DOS era. As the market shifted to ROMs, ROM size came to dominate decisions about how large
5300-614: The PDP-8 , which often shipped with 4 KB of main memory . By the late 1960s, DEC salesmen, especially in the educational sales department, found that their potential customers were not interested in FOCAL and were looking elsewhere for their systems. This prompted David H. Ahl to hire a programmer to produce a BASIC for the PDP-8 and other DEC machines. Within the year, all interest in alternatives like JOSS and FOCAL had disappeared. The introduction of
5406-663: The SWTPC (a 6800 system) on a legal pad. Steve Wozniak wrote the code to Integer BASIC by hand, translating the assembler code instructions into their machine code equivalents and then uploading the result to his computer. (Because of this, the program was very hard to change, and Wozniak was not able to modify it quickly enough for Steve Jobs , who subsequently licensed BASIC from Microsoft. ) Gates and Allen did not have an Altair system on which to develop and test their interpreter. However, Allen had written an Intel 8008 emulator for their previous venture, Traf-O-Data , that ran on
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#17328548654895512-517: The free software movement . Many firms developed BASIC interpreters. In 1976, SCELBI introduced SCELBAL for the 8008 and the University of Idaho and Lawrence Livermore Laboratory announced that they would be publishing to the public domain LLL BASIC, which included floating-point support. In 1977, the Apple II and TRS-80 Model I each had two versions of BASIC, a smaller version introduced with
5618-499: The original Macintosh computer and was developed by Donn Denman, Marianne Hsiung, Larry Kenyon, and Bryan Stearns. MacBASIC was released as beta software in 1985 and was adopted for use in places such as the Dartmouth College computer science department, for use in an introductory programming course. It was doomed to be the second Apple-developed BASIC killed in favor of a Microsoft BASIC. In November 1985, Apple abruptly ended
5724-483: The retrocomputing hobby. Higher level programming languages on systems with extensive RAM have simplified implementing BASIC interpreters. For instance, line management is simple if your implementation language supports sparse matrixes , variable management is simple with associative arrays , and program execution is easy with eval functions. As examples, see the open-source project Vintage BASIC, written in Haskell or
5830-420: The transistor in the mid-1950s, mainframes began to be built. These still needed professional operators who manually do what a modern operating system would do, such as scheduling programs to run, but mainframes still had rudimentary operating systems such as Fortran Monitor System (FMS) and IBSYS . In the 1960s, IBM introduced the first series of intercompatible computers ( System/360 ). All of them ran
5936-583: The 1978 American National Standards Institute (ANSI) Minimal BASIC standard, but was itself an incomplete implementation with integer arithmetic only. The ANSI standard was published after the design of the first generation of interpreters for microcomputers. Common components of a BASIC interpreter: Early microcomputers lacked development tools, and programmers either developed their code on minicomputers or by hand. For instance, Dick Whipple and John Arnold wrote Tiny BASIC Extended directly in machine code, using octal . Robert Uiterwyk handwrote MICRO BASIC for
6042-705: The 6502. In 1979, Warren Robinett developed the BASIC Programming cartridge for Atari, Inc. , even though it only supported programs with 9 lines of code (64 characters in total). Also in 1979, Texas Instruments released TI BASIC with its TI-99/4 , which would sell nearly 3 million systems when revamped as the TI-99/4A. Sinclair BASIC was developed for the ZX-80 by John Grant and Steve Vickers of Nine Tiles. In 1980, Sophie Wilson of Acorn Computers developed Atom BASIC , which she later evolved into BBC BASIC , one of
6148-410: The CPU for every byte or word transferred, and having the CPU transfer the byte or word between the device and memory, would require too much CPU time. Data is, instead, transferred between the device and memory independently of the CPU by hardware such as a channel or a direct memory access controller; an interrupt is delivered only when all the data is transferred. If a computer program executes
6254-474: The CPU to re-enter supervisor mode , placing the kernel in charge. This is called a segmentation violation or Seg-V for short, and since it is both difficult to assign a meaningful result to such an operation, and because it is usually a sign of a misbehaving program, the kernel generally resorts to terminating the offending program, and reports the error. Windows versions 3.1 through ME had some level of memory protection, but programs could easily circumvent
6360-534: The application program, which then interacts with the user and with hardware devices. However, in some systems an application can request that the operating system execute another application within the same process, either as a subroutine or in a separate thread, e.g., the LINK and ATTACH facilities of OS/360 and successors . An interrupt (also known as an abort , exception , fault , signal , or trap ) provides an efficient way for most operating systems to react to
6466-586: The basis for his own version. Integer BASIC was released on cassette for the Apple I , and was supplied in ROM when the Apple II shipped in the summer of 1977. Other members of the Homebrew Computer Club began circulating copies of Altair BASIC on paper tape, causing Gates to write his Open Letter to Hobbyists , complaining about this early example of software piracy . Partially in response to Gate's letter, and partially to make an even smaller BASIC that would run usefully on 4 KB machines, Bob Albrecht urged Dennis Allison to write their own variation of
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#17328548654896572-478: The computer time for the first year of software development was $ 40,000. Not that Allen couldn't handcode in machine language. While on final approach into the Albuquerque airport on a trip to demonstrate the interpreter, Allen realized he had forgotten to write a bootstrap program to read the tape into memory. Writing in 8080 machine language, Allen finished the program before the plane landed. Only when he loaded
6678-453: The computer's memory. Various methods of memory protection exist, including memory segmentation and paging . All methods require some level of hardware support (such as the 80286 MMU), which does not exist in all computers. In both segmentation and paging, certain protected mode registers specify to the CPU what memory address it should allow a running program to access. Attempts to access other addresses trigger an interrupt, which causes
6784-549: The default application that computers would launch. Users were expected to use the BASIC interpreter to type in programs or to load programs from storage (initially cassette tapes then floppy disks ). BASIC interpreters are of historical importance. Microsoft 's first product for sale was a BASIC interpreter ( Altair BASIC ), which paved the way for the company's success. Before Altair BASIC, microcomputers were sold as kits that needed to be programmed in machine code (for instance,
6890-471: The details of how interrupt service routines behave vary from operating system to operating system. However, several interrupt functions are common. The architecture and operating system must: A software interrupt is a message to a process that an event has occurred. This contrasts with a hardware interrupt — which is a message to the central processing unit (CPU) that an event has occurred. Software interrupts are similar to hardware interrupts — there
6996-411: The entire program in a multi-step process and produce a second file that is directly executable in the host computer's underlying machine language without reference to the source code. This code is often made up of calls to pre-written routines in the language's runtime system . The executable will normally be smaller than the source code that created it. The main disadvantage of compilers, at least in
7102-422: The environment. Interrupts cause the central processing unit (CPU) to have a control flow change away from the currently running program to an interrupt handler , also known as an interrupt service routine (ISR). An interrupt service routine may cause the central processing unit (CPU) to have a context switch . The details of how a computer processes an interrupt vary from architecture to architecture, and
7208-413: The first microcomputers in the mid-1970s continued the explosive growth of BASIC, which 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 minis or mainframes. 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
7314-515: The first interpreters to offer structured BASIC programming, with named DEF PROC / DEF FN procedures and functions, REPEAT UNTIL loops, and IF THEN ELSE structures inspired by COMAL . Jan Jones developed SuperBASIC , another British BASIC supporting structured programming, for the Sinclair QL . In 1983, Randall Hyde developed SmartBASIC for the Coleco Adam . Richard Clayton, Chris Hall, and Paul Overell developed Mallard BASIC for
7420-469: The function Iso will act like an extension to the operating system. Similarly, according to the QL User Guide, "many of the operating system commands are themselves defined as procedures." ctrl + space 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,
7526-410: The hardware checks that the software is only executing legal instructions, whereas the kernel has unrestricted powers and is not subject to these checks. The kernel also manages memory for other processes and controls access to input/output devices. The operating system provides an interface between an application program and the computer hardware, so that an application program can interact with
7632-493: The hardware only by obeying rules and procedures programmed into the operating system. The operating system is also a set of services which simplify development and execution of application programs. Executing an application program typically involves the creation of a process by the operating system kernel , which assigns memory space and other resources, establishes a priority for the process in multi-tasking systems, loads program binary code into memory, and initiates execution of
7738-399: The historical context, is that they require large amounts of temporary memory. As the compiler works, it is producing an ever-growing output file that is being held in memory along with the original source code. Additional memory for temporary lookups, notably line numbers in the case of BASIC, adds to the memory requirement. Computers of the era had very small amounts of memory; in modern terms
7844-418: The indirect pollution of important processor structures (like CPU caches , the instruction pipeline , and so on) which affects both user-mode and kernel-mode performance. The first computers in the late 1940s and 1950s were directly programmed either with plugboards or with machine code inputted on media such as punch cards , without programming languages or operating systems. After the introduction of
7950-536: The initial releases of the machines and a licensed Microsoft version introduced later as interest in the platforms increased. Microsoft ported its interpreter to the MOS 6502 , which quickly became one of the most popular microprocessors of the 8-bit era. When new microcomputers began to appear, such as the Commodore PET , their manufacturers licensed a Microsoft BASIC, customized to the hardware capabilities. By 1978, MS BASIC
8056-404: The interrupt request, the operating system will: When the writing process has its time slice expired, the operating system will: With the program counter now reset, the interrupted process will resume its time slice. Among other things, a multiprogramming operating system kernel must be responsible for managing all system memory which is currently in use by the programs. This ensures that
8162-431: The kernel—and applications—all other software. There are three main purposes that an operating system fulfills: With multiprocessors multiple CPUs share memory. A multicomputer or cluster computer has multiple CPUs, each of which has its own memory . Multicomputers were developed because large multiprocessors are difficult to engineer and prohibitively expensive; they are universal in cloud computing because of
8268-498: The language. 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
8374-400: The memory allocated to a different one. Around the same time, teleprinters began to be used as terminals so multiple users could access the computer simultaneously. The operating system MULTICS was intended to allow hundreds of users to access a large computer. Despite its limited adoption, it can be considered the precursor to cloud computing . The UNIX operating system originated as
8480-634: The microcomputer era, then faded to become just another application in the DOS and GUI era, and today survives in a few niches related to game development, retrocomputing, and teaching. First implemented as a compile-and-go system rather than an interpreter, BASIC emerged as part of a wider movement towards time-sharing systems. General Electric , having worked on the Dartmouth Time-Sharing System and its associated Dartmouth BASIC , wrote their own underlying operating system and launched an online time-sharing system known as Mark I featuring
8586-493: The microcomputers of the day. In 1972, HP introduced the HP 9830A programmable desktop calculator with a BASIC Plus interpreter in read-only memory (ROM). In June 1974, Alfred Weaver, Michael Tindall, and Ronald Danielson of the University of Illinois at Urbana-Champaign proved it was possible to produce "A BASIC Language Interpreter for the Intel 8008 Microprocessor," in their paper of
8692-465: The need for source listings less important. Additionally, increasingly sophisticated command shells like MS-DOS and the Mac GUI became the primary user interface , and the need for BASIC to act as the shell disappeared. The use of BASIC interpreters as the primary language and interface to systems had largely disappeared by the mid-1980s. BASIC helped jumpstart the time-sharing era, became mainstream in
8798-408: The need to use it. A general protection fault would be produced, indicating a segmentation violation had occurred; however, the system would often crash anyway. The use of virtual memory addressing (such as paging or segmentation) means that the kernel can choose what memory each program may use at any given time, allowing the operating system to use the same memory locations for multiple tasks. If
8904-408: The open-source Android operating system (introduced 2008), with a Linux kernel and a C library ( Bionic ) partially based on BSD code, became most popular. The components of an operating system are designed to ensure that various parts of a computer function cohesively. With the de facto obsoletion of DOS , all user software must interact with the operating system to access hardware. The kernel
9010-457: The original IBM PC . According to Mark Jones Lorenzo, given the scope of the language, "GW-BASIC is arguably the ne plus ultra of Microsoft's family of line-numbered BASICs stretching back to the Altair--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 . MacBASIC featured a fully interactive development environment for
9116-421: The piping. Signals may be classified into 7 categories. The categories are: Input/output (I/O) devices are slower than the CPU. Therefore, it would slow down the computer if the CPU had to wait for each I/O to finish. Instead, a computer may implement interrupts for I/O completion, avoiding the need for polling or busy waiting. Some computers require an interrupt for each character or word, costing
9222-452: The price of Microsoft's Altair BASIC also led to early collaborative software development, for Tiny BASIC implementations in general and Palo Alto Tiny BASIC specifically. BASIC interpreters fell from use as computers grew in power and their associated programs grew too long for typing them in to be a reasonable distribution format. Software increasingly came pre-compiled and transmitted on floppy disk or via bulletin board systems , making
9328-414: The program onto an Altair and saw a prompt asking for the system's memory size did he know that the interpreter worked on the Altair hardware. Operating system An operating system ( OS ) is system software that manages computer hardware and software resources, and provides common services for computer programs . Time-sharing operating systems schedule tasks for efficient use of
9434-546: The project as part of a deal with Microsoft to extend the license for BASIC on the Apple II . \ BASIC interpreters were not just an American/British development. In 1984, Hudson Soft released Family BASIC in the Japanese market for Nintendo's Family Computer video game console, an integer-only implementation designed for game programming, based on Hudson Soft BASIC for the Sharp MZ80 (with English keywords). Turbo-Basic XL
9540-459: The same name, though their application was deployed to an 8008 simulator for the IBM 360/75 and required 16 KB. In January 1975, the Altair 8800 was announced and sparked the microcomputer revolution. One of the first microcomputer versions of BASIC was co-written by Gates, Allen, and Monte Davidoff for their newly formed company, Micro-Soft. This was released by MITS in punch tape format for
9646-418: The same operating system— OS/360 —which consisted of millions of lines of assembly language that had thousands of bugs . The OS/360 also was the first popular operating system to support multiprogramming , such that the CPU could be put to use on one job while another was waiting on input/output (I/O). Holding multiple jobs in memory necessitated memory partitioning and safeguards against one job accessing
9752-577: The second edition documented keywords from over 250 different computers, showcasing the explosive growth of the microcomputer era. With the rise of disk operating systems and later graphical user interfaces , BASIC interpreters became just one application among many, rather than providing the first prompt a user might see when turning on a computer. In 1983, the TRS-80 Model 100 portable computer debuted, with its Microsoft BASIC implementation noteworthy for two reasons. First, programs were edited using
9858-400: The signal number (in mnemonic format) to be sent. (The abrasive name of kill was chosen because early implementations only terminated the process.) In Unix-like operating systems, signals inform processes of the occurrence of asynchronous events. To communicate asynchronously, interrupts are required. One reason a process needs to asynchronously communicate to another process solves
9964-465: The simple text editor, TEXT, rather than typed in line by line (but line numbers were still required). Second, this was the last Microsoft product that Bill Gates developed personally. Also in 1983, Microsoft began bundling GW-BASIC with DOS. Functionally identical to IBM BASICA , its BASIC interpreter was a fully self-contained executable and did not need the Cassette BASIC ROM found in
10070-400: The size of the machine needed. The different CPUs often need to send and receive messages to each other; to ensure good performance, the operating systems for these machines need to minimize this copying of packets . Newer systems are often multiqueue —separating groups of users into separate queues —to reduce the need for packet copying and support more concurrent users. Another technique
10176-467: The subsequent history of these different implementations.) Many vendors did "argue with that" and used other firms or wrote their own interpreters. In September 1978, Shepardson Microsystems was finishing Cromemco 16K Structured BASIC for the Z80 -based Cromemco S-100 bus machines. Paul Laughton and Kathleen O'Brien then created Atari BASIC as essentially a pared-down version of Cromemco BASIC ported to
10282-442: The system and may also include accounting software for cost allocation of processor time , mass storage , peripherals, and other resources. For hardware functions such as input and output and memory allocation , the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or
10388-518: The time-sharing services. These machines had very small main memory , perhaps as little as 4 KB in modern terminology, and lacked the high-performance storage like hard drives that make compilers practical. In contrast, an interpreter would take fewer computing resources, at the expense of performance. In 1968, Hewlett Packard introduced the HP 2000 , a system that was based around its HP Time-Shared BASIC interpreter. In 1969, Dan Paymar and Ira Baxter wrote another early BASIC interpreter for
10494-403: The user ran the program, the editor exited and ran the compiler, which read that file and produced the executable code, and then finally the compiler would exit and run the resulting program. Splitting the task up in this fashion reduced the amount of memory needed by any one of the parts of the overall BASIC system; at any given time, only the editor, compiler, or runtime had to be loaded, the rest
10600-473: The world. Middleware , an additional software layer between the operating system and applications, is often used to improve consistency. Although it functions similarly to an operating system, it is not a true operating system. Embedded operating systems are designed to be used in embedded computer systems , whether they are internet of things objects or not connected to a network. Embedded systems include many household appliances. The distinguishing factor
10706-449: Was a de facto standard and practically every home computer of the 1980s included it in ROM . In 1980, as part of a larger licensing deal that included other languages and PC DOS , IBM rejected an overture from Atari and instead licensed MS-BASIC over its own implementation, eventually releasing four versions of IBM BASIC , each much larger than prior interpreters (for instance, Cartridge BASIC took 40 KB). Don Estridge , leader of
10812-399: Was on storage. While mainframes had small amounts of memory, minicomputers had even smaller amounts: 4 and 8 KB systems were typical in the 1960s. But far more importantly, minicomputers tended to lack any form of high-performance storage; most early designs used punch tape as a primary storage system, and magnetic tape systems were for the high end of the market. In this environment,
10918-461: Was one of the first second-generation BASICs to be integrated into a microcomputer's operating system (unlike BBC BASIC which preceded it in 1981), making the OS user-extendable—as done by Linus Torvalds in his formative years. The function below illustrates the last eight of these features. After having RUN it, entering will print FRI to the screen. Until cleared (e.g. by entering NEW ),
11024-569: Was published in the September 1975 issue of the People's Computer Company (PCC) newsletter. The grammar is listed below in Backus–Naur form . In the listing, an asterisk (" * ") denotes zero or more of the object to its left — except for the first asterisk in the definition of " term ", which is the multiplication operator; parentheses group objects; and an epsilon (" ε ") signifies the empty set. As
11130-406: Was the first popular computer to use a graphical user interface (GUI). The GUI proved much more user friendly than the text-only command-line interface earlier operating systems had used. Following the success of Macintosh, MS-DOS was updated with a GUI overlay called Windows . Windows later was rewritten as a stand-alone operating system, borrowing so many features from another ( VAX VMS ) that
11236-754: Was used to develop proprietary in-house applications as well as published applications. In 1993, Microsoft released Visual Basic for Applications , a scripting language for Microsoft Office applications, which supersedes and expands on the abilities of earlier application-specific macro programming languages such as Word's WordBASIC (which had been introduced in 1989). In 1996, Microsoft released VBScript as an alternative to JavaScript for adding interactive client-side functionality to web pages viewed with Internet Explorer . In 1999, Benoît Minisini released Gambas as an alternative for Visual Basic developers who had decided to migrate to Linux . In 2000, Lee Bamber and Richard Vanner released DarkBASIC ,
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