GuruIntroduction
A computer system includes components that work together to convert data into information. Data is entered via the input unit, processed by the CPU, and output to the user. Memory stores and processes data. These parts—CPU, input, output, and memory—make up the computer's hardware.
Components of computer system
There are several computer systems in the market with a wide variety of makes, models, and peripherals.In general, a computer system comprises the following components:
- Input Unit: This unit accepts instructions and data.
- Central Processing Unit (CPU): This unit performs processing of instructions and data inside the computer.
- Output Unit: This unit communicates the results to the user.
- Memory/Storage Unit: This unit stores temporary and final results.
Input Unit
- The input unit consists of various input devices—such as the keyboard, mouse, light pen, and others—connected to the computer. These devices are electromechanical and allow users to enter data and instructions. Since different input devices produce data in varying formats, the input unit converts this information into a form the computer can understand. It then transmits the converted data and instructions to the CPU for processing.
Central Processing Unit
- The central processing unit (CPU), often called the 'brain' of a computer system, converts input data into meaningful output information.It is a highly complex, extensive set of electronic circuitry, which executes stored program instructions. It controls all the internal and external devices, performs arithmetic and logic operations, and operates only on binary data, that is, data composed of 1s and 0s.In addition, it also controls the usage of main memory to store data and instructions and controls the sequence of operations.
- The central processing unit consists of three main subsystems, the Arithmetic/Logic Unit (ALU),the Control Unit (CU), and the Registers. The three subsystems work together to provide operational capabilities to the computer.
Arithmetic/Logic Unit
The arithmetic/logic unit (ALU) contains the electronic circuitry that executes all arithmetic and logical operations on the data made available to it. The data required to perform the arithmetic and logical functions are inputs from the designated registers. ALU comprises the following two units:
- Arithmetic unit:The arithmetic unit contains the circuitry that is responsible for performing the actual computing and carrying out the arithmetic calculations, such as addition, subtraction, multiplication, and division. It can perform these operations at a very high speed.
- Logic unit: The logic unit enables the CPU to perform logical operations based on the instructions provided to it.These operations are logical comparison between data items.The logic unit can compare numbers, letters, or special characters and can then take action based on the result of the comparison. Logical operations of Logic unit test for three conditions: equal-to condition, less-than condition, and greater-than condition.
Control Unit
- The control unit of the CPU contains circuitry that uses electrical signals to direct the entire computer system to carry out, or execute, stored program instructions. This unit checks the correctness of sequence of operations. It fetches program instructions from the primary storage unit, interprets them, and ensures correct execution of the program. It also controls the input/output devices and directs the overall functioning of the other units of the computer.
Registers
- Registers are special-purpose, high-speed temporary memory units that hold various types of information such as data, instructions, addresses, and the intermediate results of calculations. Essentially, they hold the information that the CPU is currently working on. Registers serve as the CPU’s working memory, providing high-speed storage for immediate data access.They work under the direction of the control unit to accept, hold, and transfer instructions or data and perform arithmetic or logical comparisons at high speed.
Output Unit
- The output unit is formed by attaching output devices such as printer, monitor, and plotter to the computer. An output device is used to present the processed data (results) to the user. The basic task of output unit is just opposite to that of input unit. It takes the outputs (which are in machine-coded form) from the CPU, converts them into the user understandable form such as characters, graphical, or audio visual,and supplies the converted results to the user with the help of output devices.
Storage Unit
- A computer system incorporates storage unit to store the input entered through input unit before processing starts and to store the results produced by the computer before supplying them to the output unit.The storage unit of a computer comprises two types of memory/storage: primary and secondary. The primary memory holds the instructions and data currently being processed by the CPU, the intermediate results produced during the course of calculations, and the recently processed data.
- While the instructions and data remain in primary memory, the CPU can access them directly and quickly. Due to the limited size of primary memory, a computer employs secondary memory, which is extensively used for storing data and instructions. It supplies the stored information to other units of the computer as and when required.
Conclusion
The recognition of the interactions among these elements allows insights into how a computer system works as an integrated whole. Regardless of whether you are an amateur or recreational user surfing the web, a professional worker breaching computational boundaries in production settings; understanding how these elements works makes your overall computer use happier. With technological development also advances the field of computer hardware, eventually rendering more splendid advancements and innovations for years to come.