The
history of computer operating systems recapitulates to a degree, the recent
history of computing.
Operating systems (OS) provide a set of functions needed and used by most application-programs on a computer, and the necessary linkages for the control and sychronization of the computer's hardware. On the first computers, without an operating system, every program needed the full hardware specification to run correctly and perform standard tasks, and its own drivers for peripheral devices like printers and card-readers. The growing complexity of hardware and application-programs eventually made operating systems a necessity.
Background
Early computers lacked any form of operating system. The user had sole use of the machine and would arrive armed with program and data, often on punched paper and tape. The program would be loaded into the machine, and the machine would be set to work until the program completed or crashed. Programs could generally be debugged via a front panel using switches and lights. It is said that
Alan Turing was a master of this on the early
Manchester Mark I machine, and he was already deriving the primitive conception of an
operating system from the principles of the
Universal Turing machine.
Later machines came with
libraries of support code, which would be linked to the user's program to assist in operations such as input and output. This was the genesis of the modern-day operating system. However, machines still ran a single job at a time; at
Cambridge University in England the job queue was at one time a washing line from which tapes were hung with different colored clothes-pegs to indicate job-priority.
As machines became more powerful, the time needed for a run of a program diminished and the time to hand off the equipment became very large by comparison. Accounting for and paying for machine usage moved on from checking the wall clock to automatic logging by the computer. Run queues evolved from a literal queue of people at the door, to a heap of media on a jobs-waiting table, or batches of punch-cards stacked one on top of the other in the reader, until the machine itself was able to select and sequence which
magnetic tape drives were online. Where program developers had originally had access to run their own jobs on the machine, they were supplanted by dedicated machine operators who looked after the well-being and maintenance of the machine and were less and less concerned with implementing tasks manually. When commercially available computer centers were faced with the implications of data lost through tampering or operational errors, equipment vendors were put under pressure to enhance the
runtime libraries to prevent misuse of system resources. Automated monitoring was needed not just for
CPU usage but for counting pages printed, cards punched, cards read, disk storage used and for signalling when operator intervention was required by jobs such as changing magnetic tapes.
All these features were building up towards the repertoire of a fully capable operating system. Eventually the
runtime libraries became an amalgamated program that was started before the first customer job and could read in the customer job, control its execution, clean up after it, record its usage, and immediately go on to process the next job. Significantly, it became possible for programmers to use symbolic program-code instead of having to hand-encode binary images, once task-switching allowed a computer to perform translation of a program into binary form before running it. These resident background programs, capable of managing multistep processes, were often called monitors or monitor-programs before the term OS established itself.
An underlying program offering basic hardware-management, software-scheduling and resource-monitoring may seem a remote ancestor to the user-oriented OSes of the
personal computing era. But there has been a shift in meaning. With the era of commercial computing, more and more "secondary" software was bundled in the OS package, leading eventually to the perception of an OS as a complete user-system with utilities, applications (such as text editors and file managers) and configuration tools, and having an integrated
graphical user interface. The true descendant of the early operating systems is what we now call the "
kernel". In technical and development circles the old restricted sense of an OS persists because of the continued active development of
embedded operating systems for all kinds of devices with a data-processing component, from hand-held gadgets up to industrial robots and
real-time control-systems, which do not run user-applications at the front-end. An embedded OS in a device today is not so far removed as one might think from its ancestor of the 1950s.
The broader categories of systems and application software are discussed in the computer software article.
The mainframe era
Early operating systems were very diverse, with each vendor producing one or more operating systems specific to their particular hardware. Every operating system, even from the same vendor, could have radically different models of commands, operating procedures, and such facilities as debugging aids. Typically, each time the manufacturer brought out a new machine, there would be a new operating system. This state of affairs continued until the 1960s when IBM developed the
System/360 series of machines which all used the same instruction architecture. Because there were enormous performance differences across the range, a single operating system could not be used and a family of operating systems were developed.
See: OS/360. (The problems encountered in the development of the OS/360 are legendary, and are described by
Fred Brooks in
The Mythical Man-Month—a book that has become a classic of
software engineering).
OS/360 evolved to become successively
MFT,
MVT,
SVS,
MVS,
MVS/XA,
MVS/ESA,
OS/390 and
z/OS, that includes the UNIX kernel as well as a huge amount of new functions required by modern mission-critical applications running on the
zSeries mainframes. It is worth mentioning, that IBM maintained full compatibility with the past, so that programs developed in the sixties can still run under z/OS with no change. Although z/OS runs UNIX applications, it is a
proprietary OS.
Control Data Corporation developed the Scope operating system in the 1960s, for batch processing. In cooperation with the University of Minnesota, the KRONOS and later the NOS operating systems were developed during the 1970s, which supported simultaneous batch and timesharing use. Like many commercial timesharing systems, its interface was an extension of the
Dartmouth BASIC operating systems, one of the pioneering efforts in timesharing and programming languages.
In the late 1970s, Control Data and the University of Illinois developed the
PLATO operating system, which used plasma panel displays and long-distance time sharing networks. Plato was remarkably innovative for its time, featuring real-time chat, and multi-user graphical games.
UNIVAC, the first commercial computer manufacturer, produced a series of EXEC operating systems. Like all early main-frame systems, this was a batch-oriented system that managed magnetic drums, disks, card readers and line printers. In the 1970s, UNIVAC produced the Real-Time Basic (RTB) system to support large-scale time sharing, also patterned after the Dartmouth BASIC system.
General Electric and MIT developed
General Comprehensive Operating System (or General Electric Comprehensive Operating System) known as
GECOS and later
GCOS when General Electric's computer business was acquired by
Honeywell. GECOS introduced the concept of ringed security privilege levels.
Digital Equipment Corporation developed many operating systems for its various computer lines, including the simple
RT-11 system for its 16-bit
PDP-11 class machines, the VMS system for the 32-bit VAX computer, and TOPS-10 and TOPS-20 time sharing systems for the 36-bit PDP-10 class systems. Prior to the widespread use of UNIX, TOPS-10 was a particularly popular system in universities, and in the early ARPANET community.
Minicomputers and the rise of UNIX
The beginnings of the
UNIX operating system was developed at AT&T Bell Laboratories in the late 1960s. Because it was essentially free in early editions, easily obtainable, and easily modified, it achieved wide acceptance. It also became a requirement within the Bell systems operating companies. Since it was written in a high level language, when that language was ported to a new machine architecture
UNIX was also able to be ported. This portability permitted it to become the choice for a second generation of minicomputers and the first generation of
workstations. By widespread use it exemplified the idea of an operating system that was conceptually the same across various hardware platforms. It still was owned by AT&T and that limited its use to groups or corporations who could afford to license it.
Many early operating systems were collections of utilities to allow users to run software on their systems. There were some companies who were able to develop better systems, such as early Digital Equipment Corporation systems, but others never supported features that were useful on other hardware types.
In the late 1960s through the late 1970s, several hardware capabilities evolved that allowed similar or ported software to run on more than one system. Early systems had utilized
Microprogramming to implement features on their systems in order to permit different underlying architecture to appear to be the same as others in a series. In fact most 360's after the 360/40 (except the 360/165 and 360/168) were microprogrammed implementations.
One system which evolved in this time frame was the
Pick operating system. The Pick system was developed and sold by Microdata Corporation who created the precursors of the system . The system is an example of a system which started as a database application support program, graduated to system work, and still exists across a wide variety of systems supported on most
UNIX systems as an addon database system.
Other packages such as Oracle are
middleware and contain many of the features of operating systems, but are in fact large applications supported on many hardware platforms.
As hardware was packaged in ever larger amounts in small packages, first the bit slice level of integration in systems, and then entire systems came to be present on a single chip. This type of system in small 4 and 8 bit processors came to be known as
microprocessors. Most were not microprogrammed, but were completely integrated general purpose processors.
The case of 8-bit home computers and game consoles
Home computers
Although most smallest 8-bit
home computers of the
1980s, such as the
Commodore 64, the
Amstrad CPC,
ZX Spectrum series and others
could use a "normal" disk-loading operating system, such as
CP/M or
GEOS they could generally work
without one. In fact, most if not all of these computers shipped with a built-in
BASIC interpreter on ROM, which also served as a crude operating system, allowing minimal
file management operations (such as deletion, copying, etc.) to be performed and sometimes disk formatting, along of course with
application loading and execution, which sometimes required a non-trivial command sequence, like with the
Commodore 64.
The fact that the majority of these machines were bought for entertainment and educational purposes and were seldom used for more "serious" or business/science oriented applications, partly explains why a "true" operating system was not necessary.
Another reason is that they were usually single-task and
single-user machines and shipped with minimal amounts of
RAM, usually between 4 and 256
kilobytes, with 64 and 128 being common figures, and 8-bit processors, so an operating system's
overhead would likely compromise the performance of the machine without really being necessary.
Even the rare
word processor and
office suite applications were mostly self-contained programs which took over the machine completely, as also did
video games.
Finally, most of these machines didn't even ship with a built-in
flexible disk drive, which made using a disk-based OS
impossible or a luxury option.
Game consoles and video games
Since virtually all video game consoles and
arcade cabinets designed and built after
1980 were true digital machines (unlike the analog
Pong clones and derivatives), some of them carried a minimal form of
BIOS or built-in game, such as the
ColecoVision, the
Sega Master System and the
SNK Neo Geo. There were however successful designs where a BIOS was not necessary, such as the
Nintendo NES and its clones.
Modern day game consoles and videogames, starting with the
PC-Engine, all have a minimal BIOS that also provides some interactive utilities such as
memory card management,
Audio or
Video CD playback,
copy prevention and sometimes carry
libraries for developers to use etc.
Few of these cases, however, would qualify as a "true" operating system.
The most notable exceptions are probably the
Dreamcast game console which includes a minimal BIOS, like the
PlayStation, but can load the
Windows CE operating system from the game disk allowing easily porting of games from the
PC world, and the
Xbox game console, which is little more than a disguised Intel-based
PC running a secret, modified version of
Microsoft Windows in the background.
Furthermore, there are
Linux versions that will run on a
PlayStation or
Xbox and maybe other game consoles as well, provided they have access to a large mass storage device and
have a reasonable amount of RAM (the bare minimum for a
GUI is around 512
kilobytes, as the case of the
Commodore Amiga or early
ATARI ST shows.
GEOS however ran on a stock C64 which came with as little as 64
kilobytes).
Long before that,
Sony had released a kind of
development kit called the
Net Yaroze for its first
PlayStation platform, which provided a series of programming and developing tools to be used with a normal PC and a specially modified "Black PlayStation" that could be interfaced with a PC and download programs from it. These operations require in general a functional OS on both platforms involved.
In general, it can be said that videogame consoles and arcade coin operated machines used at most a built-in
BIOS during the
1970s,
1980s and most of the
1990s, while from the
PlayStation era and beyond they started getting more and more sophisticated, to the point of requiring a generic or custom-built OS for aiding in development and expandability.
The personal computer era: Apple, PC/MS/DR-DOS and beyond
The development of microprocessors made inexpensive computing available for the
small business and hobbyist, which in turn led to the widespread use of interchangeable hardware components using a common interconnection (such as the
S-100, SS-50,
Apple II,
ISA, and
PCI buses), and an increasing need for 'standard' operating systems to control them. The most important of the early OSes on these machines was Digital Research's CP/M-80 for the 8080 / 8085 / Z-80 CPUs. It was based on several Digital Equipment Corporation operating systems, mostly for the PDP-11 architecture. MS-DOS (or PC-DOS when supplied by IBM) was based originally on CP/M-80. Each of these machines had a small boot program in ROM which loaded the OS itself from disk. The BIOS on the IBM-PC class machines was an extension of this idea and has accreted more features and functions in the 20 years since the first IBM-PC was introduced in 1981.
The decreasing cost of display equipment and processors made it practical to provide graphical user interfaces for many operating systems, such as the generic
X Window System that is provided with many UNIX systems, or other graphical systems such as
Microsoft Windows, the
RadioShack Color Computer's
OS-9, Commodore's
AmigaOS, Level II,
Apple's
Mac OS, or even
IBM's
OS/2. The original GUI was developed at Xerox Palo Alto Research Center in the early '70s (the Alto computer system) and imitated by many vendors.
See also
Further reading
history of computing is longer than the history of computing hardware and modern computing technology and includes the history of methods intended for pen and paper or for chalk and slate, with or without the aid of tables.
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Computing hardware has been an important component of the process of calculation and computer data storage since it became useful for numerical values to be processed and shared.
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history of computing hardware in former Soviet Bloc is somewhat different from that of Western countries. Since Communist party propaganda maintained that western construction was next to useless, and the West had strict export restrictions on this technology, everything had to be
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Cost and Budget Overruns: The OS/360 operating system was a classic example. This decade-long project from the 1960s and 1970s eventually produced one of the most complex software systems ever created. OS/360 was one of the first large (1000 programmer) software projects.
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programming languages. For a detailed timeline of events, see the timeline of programming languages.
Prehistory
The first programming languages predate the modern computer. From the first, the languages were codes.
..... Click the link for more information. Limited computer power: There was not enough memory or processing speed to accomplish anything truly useful. For example, Ross Quillian's successful work on natural language was demonstrated with a vocabulary of only twenty
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The graphical user interface, or "GUI" (IPA: /ˈɡuːiː/), is a computer interface that uses graphic icons and controls in addition to text.
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first multiprotocol wide area network called the NASA Science Internet, or NSI. NSI was established to provide a total integrated communications infrastructure to the NASA scientific community for the advancement of earth, space and life sciences.
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World Wide Web ("WWW" or simply the "Web") is a global information medium which users can read and write via computers connected to the Internet. The term is often mistakenly used as a synonym for the Internet itself, but the Web is a service that operates over the
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Video games were introduced as a commercial entertainment medium in 1971, becoming the basis for an important entertainment industry in the late 1970s/early 1980s in the United States, Japan, and Europe.
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timeline of events in the history of computing. For a narrative explaining the overall developments, see the related History of computing.
Computing timelines: 2400 BC-1949, 1950-1979, 1980-1989, 1990-present
Resources
..... Click the link for more information. An operating system (OS) is the software that manages the sharing of the resources of a computer. An operating system processes system data and user input, and responds by allocating and managing tasks and internal system resources as a service to users and programs of the
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history of computing is longer than the history of computing hardware and modern computing technology and includes the history of methods intended for pen and paper or for chalk and slate, with or without the aid of tables.
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Alan Mathison Turing, OBE, FRS (23 June 1912 – 7 June 1954) was an English mathematician, logician, and cryptographer.
Turing is often considered to be the father of modern computer science.
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Manchester Mark I was one of the earliest electronic computers, built at the University of Manchester in England, in 1949. It was also called Manchester Automatic Digital Machine, or MADM. It was developed from the Small-Scale Experimental Machine (SSEM) or "Baby".
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;DADDCRDAA;DAADDRDAAA;DAAADDCCRDAAAA;DAAAADDRDA
This code he placed on alternate squares -- the "F-squares" -- leaving the "E-squares" (those liable to erasure) empty.
..... Click the link for more information. In computer programming, a runtime library is a special program library used by a compiler to implement functions built into a programming language during the runtime (execution) of a computer program.
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University of Cambridge (often Cambridge University), located in Cambridge, England, is the second-oldest university in the English-speaking world and has a reputation as one of the world's most prestigious universities.
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Magnetic tape is a medium for magnetic recording generally consisting of a thin magnetizable coating on a long and narrow strip of plastic. Nearly all recording tape is of this type, whether used for recording audio or video or for computer data storage.
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In computer programming, a runtime library is a special program library used by a compiler to implement functions built into a programming language during the runtime (execution) of a computer program.
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central processing unit (CPU), or sometimes simply processor, is the component in a digital computer capable of executing a program.(Knott 1974) It interprets computer program instructions and processes data.
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In computer programming, a runtime library is a special program library used by a compiler to implement functions built into a programming language during the runtime (execution) of a computer program.
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personal computer (PC) is a computer whose original sales price, size, and capabilities make it useful for individuals.
It is unknown who coined the phrase with the intent of a small affordable computing device but John W.
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graphical user interface (GUI) is a type of user interface which allows people to interact with a computer and computer-controlled devices which employ graphical icons, visual indicators or special graphical elements called "widgets", along with text, labels or text
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kernel is the central component of most computer operating systems (OS). Its responsibilities include managing the system's resources (the communication between hardware and software components).
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An embedded system is a special-purpose computer system designed to perform one or a few dedicated functions.[1] It is usually embedded as part of a complete device including hardware and mechanical parts.
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real-time computing (RToC) is the study of hardware and software systems which are subject to a "real-time constraint"—i.e., operational deadlines from event to system response.
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System/360 Model 65 operator's console, with register value lamps and toggle switches (middle of picture) and "emergency pull" switch (upper right).]] The IBM System/360 (S/360) is a mainframe computer system family announced by IBM on April 7, 1964.
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OS/360 (Operating System/360) was a batch processing operating system developed by IBM for their then-new System/360 mainframe computer, announced in 1964. OS/360 was amongst the earliest operating systems to make direct access storage devices a prerequisite for its operation.
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Frederick Phillips Brooks, Jr.
Born March 19 1931 (1931--) (age 76)
Durham, North Carolina
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