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"Education is not a way to escape poverty, it is a way to fight it" - Mwl J. K. Nyerere
Subjects >> Form 1 >> ICS >> The Computer
A Computer
Meaning:
By definition a computer can be explained as an electronic device that accepts data, process data, manipulate data, saves data and output the results of processed data in the form of information.
What is data manipulation?
Meaning:
This is an action of performing calculations on values consisting arithmetic's and logic’s operators.
Arithmetic operators (+, -, x, /)
Logic operators (=, <, >, >=, <=)
Section of a CPU which deals with data manipulation is called ALU (Arithmetic logic unit).
What is an electronic device?
This is a device that uses direct current (DC) power to operate.
This direct current power can be obtained in batteries
Or the device itself will contain a unit called power supply that will convert an Alternative current (AC) to direct current (DC) and supply appropriate power into the device.
- Alternative current (AC)
This is the power that we get in our houses. Devices that use AC power to operate are called electrical devices.
Power supply unit (PSU) - This is a device used to convert AC power to DC.
- There are many devices that we can refer to as electronic devices, but some of them are such as;
Television set, Calculator, Microwave oven, Radio, DVD player, Mobile phones, Play stations, digital watch, computer system, Personal Digital Assistant (PDA), etc
- There are so many ways of defining a computer system, here are some examples of definitions that are acceptable,
A computer is an electronic device which process data according to set of instructions obtained in a program.
A computer is an electronic device for data processing and manipulation which outputs information.
A computer is an electronic device which use input data and transform it under influence of software to produce desired information.
Note: You can define a computer system in any way you want but note that, you must put an emphasis on the fact that a computer is an electronic device, and that a computer processes data to produce information.
A computer system is divided into two divisions
Computer hardware, andComputer software
Computer hardware
This is a physical appearance of electronic components found within a computer system, e.g.
Monitor, Central processing Unit (CPU), Keyboard, Mouse, etc
Classes of computer hardware
Input devices
Processor unit (CPU)
Output devices
- Input devices
These are those devices which are used to enter data and information into the computer.
Example; Keyboard, Mouse, Digital camera, Web Camera, Microphones, Scanner, etc
Keyboard
Digital camera
- Processor unit
Also called CENTRAL PROCESSING UNIT (CPU). This is where all activities of a computer are done.
Comprises items such as;
Processor chip, Motherboard, Power supply unit, Memory, etc
Processor unit (CPU)
Processor chip (CPU Chip)
- Output devices
These devices are used to display data and information from the computer in the form of softcopy and hardcopy. This class includes devices such as,
Monitor, Printer, Speaker, Projector, plotter, beamer, etc
Monitor
Projector
note:
- Softcopy- This is the display of information that is obtained through monitor or projector.
- Hardcopy- This is the display of information from the computer on a piece of paper.
The INPUT-PROCESS-OUTPUT (IPO) as a method of computer operations
As computers are able to
Accept data
Process data, and
Produce the results of processed data in the form of information, then
This process can be named as Input-Process-Output (IPO).
Example:
Let us look at a calculator and a computer system and see how they undergo the IPO process.
A calculator's IPO
When you press a number (e.g. 1) and that number appears on the screen, this process is called INPUT.
When you input all the information necessary, calculator will do all the calculations. This process is called PROCESSING.
Then the calculator displays the results on the screen, this process is called OUTPUT.
A computer system's IPO
A computer system is an integrated system of hardware and software that enable data to be input, then processed and the results communicated to the user. (This paragraph can also be used as a computer's definition.)
That is INPUT-PROCESS-OUTPUT (IPO)
Steps:
1. Input Stage
- When you input data into the computer, it is converted into codes, for example in Ms-Excel the date 26th September 1964 is given a code 23646. this is because its 23646 day from 1st January 1900.
- Then the data entered should be checked to make sure it’s the right type (validation), e.g. to find a percentage of a certain number, the % is 100 not otherwise.
- Also the data should be checked that it was entered correctly (verification), meaning no typing errors when entering the data.
2. Processing stage
Processing involves turning data into information.
For example, a set of examination results could be put into a computer which then calculates the average score.
A set of examination results (Student's test scores) is input data.
The class' average score or the school's average score is the information that can be concluded (processed) from a given data.
3. Output stage
Output is when the computer communicates the results of the data processing to the user. At this point data becomes information.
The most two common ways are a screen display (softcopy) and printed paper (hardcopy).
Then, in this manner, we will come to realize that a computer do its operations in the form of circles.
A computer will accept the input data, process it and go back to fetch another data to be processed after finishing the first circle; the next fetched data could be the information that was obtained at the output stage that needs to be processed again to obtain more detailed information. This is termed as feedbacks in IPO.
Feedbacks in IPO happens whereby the information obtained at the output stage can then be used as feedback to input more data. This turns the system into a cycle.
