What is The Computer System Concept

The computer is a system of hardware devices organized according to the following system functions: Input. The input devices of a computer system include keyboards, touch screens, pens, electronicmice,optical scanners, and so on.They   convert   data   into   electronic machine-readable form for direct entry or through telecommunications links into a computer system.
Processing. The central processing unit (CPU) is the main processing component of a computer system. (In microcomputers, it is the main microprocessor. ) hi particular, the arithmetic-logic unit, one of the CPU’s major components, performs the arithmetic and logic functions required in computer processing.
Output. The output devices of a computer system include video display units, printers, audio response units, and so on. They convert electronic information produced by the computer system into human-intelligible form for presentation to end users.
Storage. The storage function of a computer system takes place in the computer’s primary storage unit, or memory, and in secondary storage devices such as magnetic disk and tape units. These devices store data and program instructions needed for processing.IWC replica watches.
Control. The control unit of the CPU is the control component of a computer system. It interprets computer program instructions and transmits directions to the other components of the computer system.
Computer System Components
The Central Processing Unit. The central processing unit is the most important hardware component of a computer system. It is also known as the CPU, the central processor or instruction processor, and as the main microprocessor in a microcomputer. Conceptually, the CPU can be subdivided into two major subunits: the arithmetic-logic unit (ALU) and the control unit. The CPU also includes specialized circuitry and devices such as registers for high-speed, temporary storage of instruction and data elements, and various subsidiary processors such as those for arithmetic operations, input/output, and telecommunications support. (Conceptually, a computer’s primary storage unit or memory is sometimes shown as part of a CPU.
The control unit obtains instructions from those stored in the primary storage unit and interprets them. Then it transmits directions to the other components of the computer system, ordering them to perform required operations. The arithmetic-logic unit performs required arithmetic and comparison operations. A computer can make logical changes from one set of program instructions to another (e. g., overtime pay versus regular pay calculations) based on the results of comparisons made in the ALU during processing.
Multiple Processors. Many current computers, from microcomputers to large mainframes, use multiple processors for their processing functions. Instead of having one CPU with a single control unit and arithmetic-logic unit, the CPUs of these computers contain several types of processing units. Let’s briefly look at the major types of such multiprocessor designs.
A support processor design relies on specialized microprocessors to help the main CPU perform a variety of functions. These microprocessors may be used for input/output, memory management, arithmetic computations, and telecommunications, thus freeing the main processor to do the primary job of executing program instructions. For example, many microcomputers rely on support microprocessors, such as arithmetic coprocessors, video display controllers, and magnetic disk controllers, to reduce the processing on their main microprocessors. A large computer may use support microprocessors called channels to control the movement of data between the CPU and input/output devices. Advanced microprocessor designs integrate the functions of several support processors on a single main microprocessor.Replica Patek Philippe
A coupled processor design uses multiple CPUs or main microprocessors to do multiprocessing, that is, execute more than one instruction at the same time. Some configurations provide a fault-tolerant capability, since multiple CPUs provide a built-in backup to each other should one of them fail.
A parallel processor design can use several instruction processors, or even hundreds or thousands, organized in clusters or networks. For example, some massively parallel designs containing thousands of processors are based on simple models of the human brain called neural networks. These systems can therefore execute many instructions at a time in parallel. This is a major departure from the traditional design of current computers, called the Von Neumann design, which executes instructions serially (one at a time). Though difficult to program, many experts consider parallel processor systems the key to providing artificial intelligence capabilities to fifth-generation computers.
* RISC Processors. Many advanced technical workstations and other computers rely on a processor design called RISC (reduced instruction set computer). This contrasts with most current computers, which use CISC (complex instruction set computer) processors. RISC processor designs optimize a CPU’s processing speed by using a smaller instruction set. That is, they use a smaller number of the basic machine instructions than a processor is capable of executing. By keeping the instruction set simpler than CISC processors and using more complex software, a RISC processor can reduce the time needed to execute program instructions.
Computer Processing Speeds. How fast are computer systems? Computer operating speeds that were formerly measured in milliseconds (thousandths of a second) are now being measured in the microsecond (millionth of a second) and nanosecond (billionth of a second) range, with picoseconds (trillionth of a second) speed being attained by some computers. Such speeds seem almost incomprehensible. For example, an average person taking one step each nanosecond would circle the earth about 20 times in one second!
Many microcomputers and minicomputers, and most mainframe computers,operate at nanosecond speeds and can thus process several million instructions per second (MIPS^). Another measure of processing speed is megahertz (MHz), or millions of cycles per second. It is commonly used to rate microprocessors by the speed of their timing circuits.  However, megahertz ratings can be misleading indicators of the effective processing speeds of microprocessors as measured in MIPS and other measures. That’s because processing speed depends  on  factors  such  as  the  size  of circuitry  paths,   or busses,   that  interconnect microprocessor components, the use of high-speed memory caches, and the use of specialized microprocessors such as a math coprocessor to do arithmetic calculations faster.