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THE EVOLUTION OF OPERATING SYSTEMS Nechiele T Whittington Kaplan College IT320-05 Operating Systems Concepts Instructor: Denver Martin January 17, 2010 OS EVOLUTION - 2 Everything has to start from somewhere. The concept of the computer operating system evolved from several versions of straight forward programming and assembly languages to uniprogramming and multiprogramming batch systems, to time-sharing applications to finally become what we recognize today as an operating system application. The concept of the operating system started in the late 1940’s with a notable blip in 1954 with the introduction of the IBM 701 open shop application, where users had to manually operate the computer processors and were allotted a minimum amount of time to initiate and complete their computations. (Hansen, “Evolution of Operating Systems” 2000). According to Stallings (Stallings, “Operating Systems, Internals and Design Principals” 2009), “…computers were run from a console consisting of display lights, toggle switches, some form of input device and a printer.” While the computer was being used, any errors would be noted by system lights and a printer readout. Of course, this would halt the entire system which would impact the current user and those immediately scheduled to use the system afterwards since all processing was done in the order received. As you can imagine, this ‘serial processing’ operation was less than stellar. It was considered extremely inefficient because of the excessive resources being wasted. As noted by Brinch Hanson, “The cost of the wasted computer time was $146,000 per month in 1954 dollars!” (Hanson, 2000, “Evolution”) This was a result of the length of time consumed by users just trying to set up their calculations for processing! The next evolutionary step towards the creation of operating systems was the implementation of ‘batch processing’. It was a widely agreed upon idea that computer resources were wasted with the way things were done up until this point. Then someone OS EVOLUTION - 3 got the idea to take the users out of the equation and let the computer set up their workloads on their own. IBM introduced a more streamlined system under the IBM 704 system. This system used operators that processed punch card information into satellite computer feeds that were then translated onto magnetic tapes. Those tapes were then “mounted on a tape station connected to a main computer.”(Hanson, 2000 “Evolution”) This was an improvement over the serial processing set-up because it cut out a lot of user error, but the application was still time consuming. This wasn’t a big leap in terms of execution as programs were still processed on a first-come, first-served basis. 1959 introduced the next step towards operating systems: the multi-programmed batch systems. As you can imagine, this process allowed multiple programs to be run at one time under the premise of multi-tasking—when one program would hit an area where it would need to wait for the I/O process, another program would be started in the interim which would improve resource utilization. Unfortunately, this still didn’t solve the problem of memory management because while the choice of programs allowed to run was ultimately left up to the processor, the necessary algorithms were still resource hogs. Thus the ideas of ‘time sharing’ and ‘spooling’ were introduced into the programming world. These ideas and applications would lay the foundations for the creation and implementation of what we understand as operating system programs today. There were many advances from 1959 to 1969 that would shape the programming world—advances that would make programmers question the veracity and more importantly, the efficiency of the use of assembly language and direct processor/memory interface for computer programming. What was being used and created just wasn’t efficient enough. People wanted more from the computer. By 1969, they got it. OS EVOLUTION - 4 In 1969, UNICS was introduced into the computer world. A C based programming language was created and used to jumpstart the computing world. It was because of UNICS that a programmer named Ken Thompson over at Bell Labs ultimately created the first version of UNIX which was based off of the C programming language. From that point on, the world of computers would never be the same (FreeDictionary.com UNIX). UNIX was the launch pad for operating systems then, and as you can imagine, is still the basis of the standard operating systems in use today. At first, while UNIX was the operating system to have, there were compatibility issues that overshadowed the overall product usefulness. The compatibility issues stemmed from the fact that vendors were creating their own versions of UNIX for competition. This was great in that it offered users the chance to try other UNIX flavors, but because there was really no standardization at the time, there really wasn’t a guideline outside of what vendors could imagine and implement to suit their particular needs. The Open Group website has a great sentence/quote that sums up the first iterations of UNIX: “In the early 1980's, the market for UNIX systems had grown enough to be noticed by industry analysts and researchers. Now the question was no longer "What is a UNIX system?" but "Is a UNIX system suitable for business and commerce?"” (The Open Group: UNIX Timeline: http://www.unix.org/what_is_unix/history_timeline.html ) Between 1969 and 1979, there were multitudes of operating systems; some were received well and some never made it out of the development arena. Operating systems like Atlas (1960’s), the Burroughs 5000 (1961), Exec II (approximately 1966), and The Edgon System (approximately 1966) were some of the more ‘notable’ ones. UNIX OS EVOLUTION - 5 would experience no less than ten different versions during this time. Then, something interesting happened… In 1991, Linus Torvalds answered the call with the creation and subsequent 1992 introduction of the first flavor of Linux. His operating system offered a stable kernel— something UNIX hadn’t achieved yet. Torvalds became something of a phenomena in the computer world because of one simple fact: Linux (unlike its predecessors) incorporated the standards, suggestions, and development of hundreds of other programmers and developers. It was (and is) a true open-source operating system that focused on the needs of its users. Because of the open-source nature of Linux, compatibility issues were negated almost as quickly as they occurred and it wasn’t bogged down in the political/bureaucratic red tape that UNIX couldn’t avoid. Some would say that Linux helped heal the “UNIX wars” rift. To date, there have been several Linux flavors released, some of the most popular being Red Hat, SuSE, and (most recent) Ubuntu. The Novell infrastructure features both Linux and Windows based applications and is often used in the backbone infrastructure of businesses worldwide. Entities like The Library of Congress are using Linux applications to help digitize and retain historic documents. The FBI uses Linux applications to link federal, state and local government systems together to hopefully improve communications and facilitate faster emergency response times. Even international governments are using Linux based applications for their research, data migration and distribution efforts. (Linux in Government: http://www.linux.org/info/linux_govt.html) OS EVOLUTION - 6 I’ve recently become a personal Linux fan myself. While other operating systems may offer universally recognized branding, I’ve come to see Linux as the more business compatible operating system platform available. I love the fact that Linux is (relatively) easily customizable and can be adapted to fit my business needs. The open-source aspect helps quite a bit in that vein; problems that I may encounter have probably been encountered, tackled and resolved before and that information is freely available should I ever need it. We’ve come a long way with computers. As a personal and business user and potential developer, I just can’t wait to see what we do next with them… OS EVOLUTION - 7 - REFERENCES: Stallings, William (2009): “Operating Systems Internals and Design Principles” Sixth Edition, Pearson/Prentice Hall, Saddle River, NJ Hansen, Brinch (2000): The Evolution of Operating Systems- http://brinchhansen.net/papers/2001b.pdf Free Dictionary.com explanation of UNIX origins: http://encyclopedia2.thefreedictionary.com/Unics The Open Group.com-UNIX History: http://www.unix.org/what_is_unix/history_timeline.html Linux Online-Linux Timeline: http://www.linux.org/info/linux_timeline.html