Chapter 1 Computer Concepts (1)

Ms. Jennifer O. Calleja | IT Instructor

Chapter 1 : Computer ConceptsIT 12 | Fundamentals of Programming and Database Theory and Applications


Objectives

•At the end of this module you should be able to:

Explain how computer works State the functions of each basic hardware

component of a computer system Classify computers


Computer

is an electronic device that accepts data, stores and processes the data and generates information as output.


Computer (stores and

process data)Data

inputinfo

output

A computer


Data and Information

Data is a raw, unprocessed data

Information is a processed data


Four Basic Functions:• Input – the procedure of feeding data into a

computer•Process – refers to the operation of

manipulating and transforming data into something useful.

Program – a set of written instructions, is what tells the computer how to manipulate and transform the data it was given into information

•Output – the result of the processing function.•Storage – computers can save data so that ir

can be used at another time.


SAQ 1-1

•How does the computer process data?


ASAQ 1-1

•The computer processes data by following a set of instructions called a program


Computer Systems Components•Hardware – refers to the tangible

components of a computer system•Software – refers to the set of instructions

written in a code.


Basic Hardware Components

•Input devices – perform the two most basic computing tasks : issuing commands and entering data.

Data entry – defined as the process of entering data into the computer memory and issuing commands that tell the processor how to work with the data.


Examples of Input device:

•Keyboard•Mouse•Trackball•Joystick•Lightpen•Video input device•Scanners



•Output Device after processing data fed into the computer with the use of input devices, the information must now be outputted in a form understood by human beings. For this purpose, computer system components collectively called as output devices are used.


Examples of Output device:

•Printer•Video monitors•Speakers•modem



•Central Processing Unit (CPU)CPU does the data processing. Its job is to fetch instructions (programs) from the main memory, decode, and execute it.


Parts of a CPU:

•Control Unit (CU)▫can be described as a sort of circuitry that

supervises and controls the path of information that runs over the processor and organizes the various activities of those units that lie inside it.

•Arithmetic Logic Unit (ALU)▫Involves comparing two items and

determining whether one is greater than, equal or less than the other.


Companies that design and Manufacture CPUs:•Intel•Motorola•DEC•SUN•IBM•AMD


SAQ 1-2

•What specific components of the computer does the arithmetic computations?


ASAQ 1-2

•The arithmetic/logic unit (ALU)



•Main Memory and Secondary Memorywhen the CPU processes the data, it uses the memory as temporary storage to aid in the calculations.


Bits and bytes

•The data and programs are stored in the memory in the form of binary digits (0 and 1). Numbers are all represented using the binary system, and text and characters are coded in binary.▫8 bits = 1 byte▫1024 bytes = 1 kilobyte▫1024 kilobytes = 1 megabytes▫1024 megabytes = 1 gigabyte


Computer Memory

•Consists of the main memory and the secondary memory. The difference between the two types of memory lies in the technology used.

•Main Memory – stores data using electric current flowing around the loop of wire.

•Secondary Memory – usually uses magnetic materials, just like those found in cassette tapes.


Comparison of Computer MemoryMemory

TypeTechnology Limitations, Advantages

and Disadvantages

Main Memory

Uses electric current

-Very expensive-Fast access-Volatile

Secondary Memory

Uses magnetic materials

-Relatively cheap-Slow access-Non-volatile


SAQ 1-3

•Why do computers need to use both types of memories (main and secondary)?


ASAQ 1-3

•It uses main memory to be able to process data at high speeds (remember how the memory is used as temporary storage?) and it uses secondary memory to preserve data.


COMPUTER SOFTWARE

•It can be categorized into two classes : ▫Applications Software ▫System Software


Application Software

•Are programs that are used by people to solve their individual needs. ▫Examples:

Word Processor Spreadsheet programs


Systems Software

•Are programs that control the operations of the computer hardware.▫Task of Systems Software

Starting up of the computer Loading Executing applications software.


CLASSIFICATION OF COMPUTERS•Computers are usually classified

according to their sizes and processing speeds. But since technology changes very rapidly, no absolute measures to classify computers exist.


Classification of Computers

•Microcomputers▫refer to small desktop

systems made popular by IBM in the early 80s. They are also called personal computers and are usually used for individual tasks such as word processing, spreadsheet computations and other interactive applications.



•Minicomputers▫are more powerful than

microcomputer and are intended to support several users who are concurrently doing different tasks. They are widely used in real time applications such as air traffic control.



•Mainframes▫are large systems that can

process huge amounts of data at a very high rate. The main difference between mainframes and minicomputers is their input/output capacity and the applications for which it is used.



•Supercomputers▫are the fastest computers

and achieve processing speeds more than 10 times that of the minicomputers. To achieve high speeds, they usually consists of several processors running simultaneously.


SAQ 1-4

•Differentiate microcomputer and minicomputers.


ASAQ 1-4

•Microcomputers are less powerful than minicomputers. They are designed for individual use, while minicomputers are designed to handle several users at a time.


Chapter 1 Computer Concepts (1)

Documents

main memory

computer

data

applications

time

information

cpu

minicomputers