An operating system (OS) is the software on a computer that manages the way different programs use its hardware, and regulates the ways that a user controls the computer.[1][2] Operating Systems is also a field of study within Applied Computer Science. Operating systems are found on almost any device that contains a computer with multiple programs—from cellular phones and video game consoles to supercomputers and web servers. Some popular modern operating systems for personal computers include Microsoft Windows, Mac OS X, and Linux[3] (see also: list of operating systems, comparison of operating systems.
Ahad, 13 Jun 2010
OPERATION SYSTEM
Meaning:--
An Operating System is a computer program that manages the resources of a computer. It accepts keyboard or mouse inputs from users and displays the results of the actions and allows the user to run applications, or communicate with other computers via networked connections.
Example of operation system :--
Such as HD,PD,CD and DVD.... Other than that is Despite running five applications simultaneously the Operating System responded immediately to mouse clicks.
Rabu, 5 Mei 2010
FUNCTION SECONDARY STORAGE
FUNCTION:---
A digital computer represents data using the binary numeral system. Text, numbers, pictures, audio, and nearly any other form of information can be converted into a string of bits, or binary digits, each of which has a value of 1 or 0. The most common unit of storage is the byte, equal to 8 bits. A piece of information can be handled by any computer whose storage space is large enough to accommodate the binary representation of the piece of information, or simply data. For example, using eight million bits, or about one megabyte, a typical computer could store a short novel.
Without a significant amount of memory, a computer would merely be able to perform fixed operations and immediately output the result. It would have to be reconfigured to change its behavior. This is acceptable for devices such as desk calculators or simple digital signal processors. Von Neumann machines differ in that they have a memory in which they store their operating instructions and data. Such computers are more versatile in that they do not need to have their hardware reconfigured for each new program, but can simply be reprogrammed with new in-memory instructions; they also tend to be simpler to design, in that a relatively simple processor may keep state between successive computations to build up complex procedural results. Most modern computers are von Neumann machines.
SECONDARY STORAGE
Meaning:--
Computer data storage, often called storage or memory, refers to computer components, devices, and recording media that retain digital data used for computing for some interval of time. Computer data storage provides one of the core functions of the modern computer, that of information retention. It is one of the fundamental components of all modern computers, and coupled with a central processing unit (CPU, a processor), implements the basic computer model used since the 1940s.
In contemporary usage, memory usually refers to a form of semiconductor storage known as random-access memory (RAM) and sometimes other forms of fast but temporary storage. Similarly, storage today more commonly refers to mass storage — optical discs, forms of magnetic storage like hard disk drives, and other types slower than RAM, but of a more permanent nature. Historically, memory and storage were respectively called main memory and secondary storage. The terms internal memory and external memory are also used.
The contemporary distinctions are helpful, because they are also fundamental to the architecture of computers in general. The distinctions also reflect an important and significant technical difference between memory and mass storage devices, which has been blurred by the historical usage of the term storage. Nevertheless, this article uses the traditional nomenclature.
PRIMARY STORAGE
Meaning:---
computer's main memory: the main memory in a computer, including the random-access memory and the read-only memory, directly accessible by the processor
Process:---
process involving functioning of id: in Freudian psychoanalysis, a basic process that is involved in the functioning of the id and is ruled by the pleasure principle
Function:--Primary storage (or main memory or internal memory), often referred to simply as memory, is the only one directly accessible to the CPU. The CPU continuously reads instructions stored there and executes them as required. Any data actively operated on is also stored there in uniform manner.
STORAGE
Meaning of storage....
1. storing or being stored: the act of storing something, or the condition of being stored
2. space for storing: space in which to store things, especially the amount of such space
3. comput medium for storing data: any device or medium used for deposit, retention, and retrieval of computer data, especially a hard disk or floppy disk
4. finance price for storing: the price charged for storing something
Picture:--
Rabu, 28 April 2010
ABOUT ICT
Founded in 1996, the International Institute for Counter-Terrorism (ICT) is the leading academic institute for counter-terrorism in the world, facilitating international cooperation in the global struggle against terrorism. ICT is an independent think tank providing expertise in terrorism, counter-terrorism, homeland security, threat vulnerability and risk assessment, intelligence analysis and national security and defense policy.
ICT Brochure
ICT also serves as a joint forum for international policymakers and scholars to share information and expertise through research papers, situation reports and academic publications for worldwide distribution. A number of international seminars, workshops and conferences are organized monthly by ICT to discuss and educate on global and regional issues of security, defense, and public policy making in order to better facilitate the exchange of perspectives, information and proposals for policy action. Finally, ICT administers the largest public domain research database on the Internet encompassing global terrorist attacks, terrorist organizations and activists in addition to statistical reports.
ICT draws upon a comprehensive and international network of individuals and organizations with unique expertise on terrorism and counter-terrorism research, public policy analysis and education dispersed all over the world, including the United States, European Union and Israel, among others. An acclaimed management and research staff at ICT spearheads the Institute's efforts to coordinate the struggle against global terrorism and leads a worldwide team of affiliates and academic partners working to encourage cooperation among experts and disseminate innovative ideas for policymakers in the fight against terrorism.
ICT is a non-profit organization located at the Interdisciplinary Center (IDC), Herzliya, Israel which relies exclusively on private donations and revenue from events, projects and programs.
Isnin, 22 Mac 2010
1900 Series computers
These varied in computing power and the models included:
ICT 1901
ICT 1902
ICT 1903
ICT 1904
ICT 1905 (similar to the 1904 but incorporating an autonomous floating-point unit)
ICT 1906
ICT 1907 (similar to the 1906 but incorporating an autonomous floating-point unit)
ICT 1909 (similar to the 1905 but with low-cost 6µs core store)
The execution time for an addition instruction ("add the contents of store location x to register y") ranged from 2.5μs for a 1906 or 1907 with 1.1μs core store, to 34μs for a 1901 with 6μs core store.
The first machine was the 1904 which was a Canadian design from the Ferranti-Packard company, originally called the FP6000, although commonly referred to within West Gorton as the FP1. It is said that this machine with core store memory fired up with its program still in store after its sea freight journey from Canada.[citation needed]
One feature of these mainframes was the common instruction set throughout the range, meaning that a program written and compiled on one machine would run unchanged on any larger machine in the range, and also on any smaller machine that had all the facilities used by the program. In fact the hardware was different between machines. To achieve this a program termed "the executive" or exec encapsulated the hardware and supplied software routines (extracodes) to supplement the hardware supplied instructions.
By 1968 ICT had merged with English Electric computers and become ICL.
Enhanced versions of the 1900 series subsequently appeared with an A suffix, an E suffix, an F suffix (for floating point), a T suffix, and an S suffix, e.g.
The operation in Stevenage, Hertfordshire, designed and built machines, typically smaller systems using the E3RM executive software
ICL 1901A
ICL 1901S/T
ICL 1902A
ICL 1902S
ICL 1902T
ICL 1903A
ICL 1903S
The operation at West Gorton, Manchester, built machines, typically larger systems using the E6RM executive software:
ICL 1903T
ICL 1904A
ICL 1904T
ICL 1904S
ICL 1905F
ICL 1906S
The 1900 Series were 24-bit word machines, supporting four 6-bit characters per word and using octal for binary short-hand — as opposed to the IBM systems, which used 8-bit bytes and hex. Basic memory on the smaller machines was 16K words (or 64 kilobytes equivalent), and there were even 8K word versions sold (although most actually had 16K memory factory installed in readiness for the certain upgrade order that followed!)—early machines using core memory (ferrite rings on a copper wire matrix) and operated on binary hand-switches on the mainframe cabinet. Despite the apparent small memory size, quite sophisticated applications were run on the equipment and computer programmers paid great attention to the efficient use (and reuse) of memory.
Input and output (I/O) consisted of 80-column cards (40-column cards—with round holes—were unable to cope with the full 64-character set), a card punch and 8-track paper tape; printed output was produced on a solid barrel line printer (120 columns wide).
The first commercial sale was made in 1964 to the Morgan Crucible Company and consisted of a 16K word 1902 with an 80-column 980-card/minute reader, a card punch, a 600 line/min printer and 4 x 20kb/s tape drives. It was soon upgraded to a 32K word memory and a floating point unit to allow for some scientific work. Incidentally this company was also the first business to order ICT's previous computer, the HEC4 (later ICT 1201) in 1955.
Early machines used storage on reels of half-inch magnetic tape and were then augmented by direct access devices (EDS, Exchangeable Disc Store) typically with capacities of 1.6Mch, 4Mch and 8Mch. By the time 30Mch packs were available they occupied a cabinet 4 feet (1.2 m) high.
After ICL had introduced the "New Range" (NR) series of computers during the 70s, marketed as the 2900 series, the 1900 series actually lived on as there was such a wealth of software written for it:
The ICL 2903/2904, designed and built in Stevenage, which were really successors to the 1902A/3A machines as they had the same target instruction set (albeit with a native 32 bit rather than 24 bit architecture)
Second generation "S3E" (microcoded) versions of the larger NR systems (such as the 2960/2966 from West Gorton, and the later 2940/50 from Stevenage), could run 1900 series code under DME (Direct Machine Environment) as an emulation as well as the New Range instruction set under the newer VME (Virtual Machine Environment)
The later availability of CME (Concurrent Machine Environment) microcode, which allowed DME and VME to co-exist (and run) concurrently on the same platform, similar to the functionality offered by virtualisation software such as VMware today
The replacement for the 2903/4 was the ME29 (Machine Environment 29) with its own operating system, TME (Transaction Machine Environment), which could still execute 1900 applications
An update of CME to CME* in the 1980s to support a small VME range called DM1 that replaced the ME29, which could run TME within a VME VM (virtual machine)
Programming languages included the assembly type language PLAN (Programming LAnguage Nineteen-hundred) and latterly COBOL for the development of commercial-orientated systems while ALGOL and FORTRAN were used for scientific work.
The basic operating system was called "Executive" and supported "multiprogramming", i.e. it was capable of running up to four programs concurrently on the 1904, and more on the larger machines. From about 1968 onwards, advanced features such as a tree-structured filestore, batch processing and multi-access with identical command languages, and spooling were provided by a privileged ("trusted") program called GEORGE.
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