STRUCTURE AND FUNCTIONS OF A COMPUTER
MAJOR FUNCTIONS AND PARTS
A computer is an electronic device operating under the controls of instructions stored in its own memory unit that can accept data (input), process data arithmetically and logically produce output for processing and store result for future use.
A computer is a device, which can perform computation, including arithmetic and logic operations, without intervention by a human being. A computer system consist not only of the device which can perform computations without human intervention but also devices which allows data to be made available for processing and devices on which data can be displayed or printed for use by human beings.
1. List the three main components of a computer system.
2. Describe the functions of the three main components of a computer system. (i) Input - involves accepting data in machine-readable form and sending it to the Central Processing Unit (CPU) for processing.
(ii) Processor - The central processing unit - controls and manipulates data to produce information. A microcomputer's CPU is contained on a single integrated circuit or microcomputer chip. These chips are called microprocessor. Microprocessor - It carries out the processing task by interpreting and executing the instruction in a program. (iii) Output - The output function involves the presenting of data externally, passing data for further processing, or sending data for storage. 3. List the three components of the central processing unit. a.
Arithmetic Logic Unit (ALU)
4. Briefly describe the functions of the following three components of the central processing unit: a. Memory - used to store program being run on the computer and data on which the program works. b. Control Unit - takes one program instruction at a time and acts upon it. The actions results in the flow of data from one part of the computer to another. c. Arithmetic and Logic Unit - the area where the computer performs simple arithmetic on the data, or compares one piece of data with another.
5. Explain what is meant by primary memory/storage.
Primary Storage (main memory) - the part of the computer that holds data and programs before and after they have been processed by the CPU.
6. Define secondary memory/storage.
Secondary Storage (auxiliary storage)- a more permanent storage for data and programs than RAM. Secondary storage uses media such as hard disk, floppy disks and CD-ROM. 7. Differentiate between random access memory (RAM) and read only memory (ROM). RAM - Primary storage that is volatile. RAM is memory where data and instructions are held temporarily. When a computer is turned off, everything is lost from memory - all the transistor switches are set to 'off' (or 'O'). This means when it is turned back on there is nothing in memory. ROM - Primary storage that is non-volatile. ROM hold data and instructions which are fixed at the time of production and cannot be changed by the user or the computer. It is also known as the permanent memory of the computer system. The computer reads the instructions and executes them automatically - they cannot be altered.
8. Identify various types of:
Direct entry creates machine-readable data that can go directly to the CPU. Direct entry includes pointing, scanning and voice-input device.
In key entry, people type input. The input usually appears on a monitor.
- Keyboard - used for typing, commands, messages and instructions and transmitting them to the CPU for interpretation and action. - Mouse - used for pointing at items displayed on the screen (selecting) and activating them by clicking the buttons. Trackballs also operate in the similar manner. - Scanner - can read...
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