Today, computers play an important part in almost every facet of our lives. So, it is important to understand how a computer works.
To do this, you must first know the basic parts of a computer. They are the input and output devices, the memory, and the CPU or central processing unit.
A computer takes in the information given to it, does a task assigned to it, and also gives you the result. The input unit takes in the information and instructions that a computer works with.
The computer’s memory stores or remembers the information and instructions given to it. The CPU processes the information and does the actual work of computing. The CPU brainfood is data!
Finally, the output unit gives you the results.
What are the input devices?
An input device is a device for entering information into a computer. Input devices include the keyboard, joystick, mouse, lightpen, touch-sensitive screen, scanner, speech-recognition device, vision system, etc.
Of these, the keyboard, mouse, and the joystick are those that you will be most familiar with.
What are a computer’s main output devices?
An output device lets a computer communicate with you. The monitor, printer, and speaker of a computer are output devices.
A monitor is a screen on which words, numbers, and graphics can be seen. The monitor is the most common output device.
The printer prints whatever is on the monitor onto paper. Printers can print words, numbers, or pictures.
A speaker gives you sound output from your computer. Some speakers are built into the computer, and some are separate.
Why is the CPU known as the ‘brain’ of the computer?
The Central Processing Unit or CPU performs the actual processing of data. It is called the ‘brain’ of the computer, because like a brain, it controls information and tells other parts what to do.
It is the single most important chip in the computer, and is made up of many electronic circuits, sometimes millions!
Each circuit is made up of transistors that strengthen electric current flowing through it or change the path of the current. The job of each circuit is to perform a very simple operation in arithmetic.
The CPU performs the system’s calculating and processing. The type of CPU in a computer also determines how fast that computer can operate.
Why is the memory unit of a computer so important?
The memory unit is the part of the computer that holds the programs that the CPU must follow and also the data or information on which the CPU must operate. Storing information is referred to as ‘placing it in memory’.
A computer system usually contains several kinds of storage, each with an individual purpose. A digital computer represents information using the binary numeral system.
In this system, 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, which is equal to 8 bits.
Why is the Arithmetic Logic Unit of the computer important?
The Arithmetic Logic Unit or ALU is a vital part of the central processing unit. Its job is to carry out calculations, adding subtracting, multiplying and dividing.
The ALU also carries out comparisons which answer questions such as, ‘is the number ‘A’ greater, less than or equal to the number B? Another name for comparing two numbers is a ‘logical operation’
In the ALU, binary numbers or ‘bits’ are handled by special storage units calledregisters. Each register has 8 or more storage positions, and a register with 8 storage positions can store 8 bits.
With the help of two or more registers, and the ability to do binary arithmetic (which is different from the arithmetic that you learn in mathematics), the ALU performs all calculations.