this notes prepared to enable the trainee to describe computer system,Describe connection ports,procedures for connecting peripherals to micro-computer system and test the system
3. 1.It accepts data or instruction by way of
input,
2. it stores data,
3. it can process data as required by the user,
4. it gives results in the form of output, and
5. it controls all operations inside a
computer.
4. Input: this is the process of entering data and
programs into the computer system.
Control Unit (CU): The process of
input,output,processing and storage is
performed under the supervision of a unit called
'Control Unit'.
It decides when to start receiving data,
when to stop it,
where to store data, etc.
It takes care of step-by-step processing of all operations
in side the computer.
5. Memory Unit: Computer is used to store data and
instructions.
Arithmetic Logic Unit (ALU): The major operations
performed by the ALU are addition(+), subtraction(-
),multiplication(x), division(/), logic and comparison(yes/no).
Output: This is the process of producing results from the
data for getting useful information.
The ALU and the CU of a computer system are jointly known
as
the central processing unit (CPU).
You may call CPU as the brain of any computer system.
6. What are the five basic operations performed by the
computer?
Define ALU, CU and CPU.
Choose the correct answer.
1. The task of performing arithmetic and logical operations is called
a. ALU
b. editing
c. storage
d. Output
2. The ALU and CU jointly are known as
a. RAM
b. ROM
c. CPU
d. None of above
3. The process of producing results from the data for getting useful information is
called
a. output
b. input
c. processing
d. storage
7. Peripheral devices are connected to the computer
externally.
These devices are used for performing some
specific functions.
Peripheral devices are as follows:
1. Input Devices
2. Output Devices
3. Other Peripherals
8.
9. INPUT DEVICES
Input devices accept data and instructions from the
user
Example
1. Keyboard
2. Mouse
3. Light Pen
4. Optical/magnetic Scanner
5. Touch Screen
6. Microphone for voice as input
7. Track Ball
10. is the most common input device.
Several kinds of keyboards are available, but
they
The keyboard in most common use is the
QWERTY board.
Generally standard keyboard has 104 keys.
In these keyboards, the cursor control keys are
duplicated to allow easier use of the numeric
pad.
11.
12. A mouse is an electro-mechanical, hand-held
device .
It is used as a pointer.
It can perform functions like selecting menu
commands, moving icons, resizing windows,
starting programs, and choosing options.
13.
14. The most common mouse uses an internal,
magnetically coated ball, to detect the
movement of the mouse across a flat surface,
Now a days Optical or laser mouse is used to
detect the movement.
15. An input device that utilizes a light-sensitive
detector to select objects on a display screen.
A light pen is similar to a mouse , except that
with a light pen you can move the pointer and
select objects on the display screen by directly
pointing to the objects with the pen.
16.
17. These devices are used for automatic data collection.
The devices of this category completely eliminate
manual input of data.
For example, the bar-code reader is actually just a special
type of image scanner.
An image scanner translates printed images into an electronic
format that can be stored in a computer’s memory, and with the
right kind of software, one can alter a stored image.
Another example of scanner is optical character recognition
(OCR) device, used by banks to convert the scanned image of a
typed or printed page into text that can be edited on the
computer.
18.
19. Touch panel displays and pads are now being
offered as alternatives to keyboard. Here the
input can be given through the computer
screen, that accepts the input through monitor;
users touch electronic buttons displayed on the
screen or they may use light pen.
20.
21. Microphone is an input device, which takes
voice as input.
The voice communication is more error-prone
than information through keyboard.
There are two types of microphones available
1. Desktop Microphone
2. Hand held Microphone
23. Trackball, a pointing device, is a mouse nlying
on its.
To move the pointer, you rotate the ball with
your thumb, your fingers, or the palm of your
hand.
There are usually one to three buttons next to
the ball, which you use just like mouse buttons.
24.
25. Output devices return processed data that is
information, back to the user.
Some of the commonly used output devices are:
1. Monitor (Visual Display Unit)
2. Printers
3. Plotter
4. Speakers
26. Out of all the output devices, monitor is perhaps
the most important output device because people
interact with this device most intensively than
others.
Computer information is displayed, visually with
a video adapter card and monitor. Information
processed within the CPU, that needs to be
visually displayed, is sent to video adapter.
The video adapter converts information from the
format used, in the same manner as a television
displays information sent to it by a cable service
28. 1. CRT
Cathode Ray Tube (CRT): CRT or Cathode Ray Tube Monitor is the
typical monitor that you see on a desktop computer.
It looks a lot like a television screen, and works the same way.
This type uses a large vacuum tube, called cathode ray tube (CRT).
2. LCD
Liquid Crystal Displays (LCD): This type of monitors are also known as
flat panel monitor. Most of these employ liquid crystal displays (LCDs) to
render images. These days LCD monitor are very popular.
29. After a document is created on the
computer, it can be sent to a printer
for a hard copy (printout). Some
printers offer special features such as
colored and large page formats.
31. Speakers are another type of
output device, which allow
you to listen to voice like
music, and conversation with
people.
32. Software refers to a set of programs that makes
the hardware perform a particular set of tasks
in particular order.
Sets of instructions are called Programs.
33.
34. System software's are sets of programs,
responsible for running the computer,
controlling various operations of computer
systems and management of computer
resources.eg: operating system (os).
35. An operating system is a system software that
provides an interface for a user to communicate
with the computer, manages hardware devices
(disk drives, keyboard, monitor, etc), manages
and maintains disk file systems and supports
application programs.
Some popular Operating systems are UNIX,
Windows and Linux
36. These are programs that bridge the gap
between the functionality of an OS and the
needs of users.
Utility programs are a broad category of
software such as compress (zip)/uncompress
(unzip) files software, anti virus software, split
and join files software, etc.
37. Application software is a set of programs, which
are written to perform specific tasks, for example:
1. Generalized packages
Word Processing Software(for preparing documents):
Word Perfect, MS-Word, OpenOffice.org Writer
Spreadsheets (Data Analysis): Lotus Smart suites, MS-
Excel, OpenOffice.org Calc, Apple Numbers
Presentations : Presentation Graphics, MS-PowerPoint,
OpenOffice.org Impress
Database Management System: MS-Access,
OpenOffice.org Base, MS-SQL Server, ORACLE
Graphics Tools: Paint shop pro, Adobe Photoshop
38. 2. Customized Packages
These are the applications that are customized (or
developed) to meet the specific requirements of an
organization/institution.
For Example: Student information details, Payroll
packages, inventory control etc.
These packages are developed using high-level
computer language.
39. What is a Port?
A port: Is a physical docking point using which an
external device can be connected to the computer.
Can also be programmatic docking point through
which information flows from a program to
computer or over the internet.
40. A port has the following characteristics:
External devices are connected to a computer
using cables and ports.
Ports are slots on the motherboard into which a
cable of external device is plugged in.
Examples of external devices attached via ports
are mouse, keyboard, monitor, microphone,
speakers etc
41.
42.
43. Serial Port
Used for external modems and older computer
mouse
Two versions : 9 pin, 25 pin model
Data travels at 115 kilobits per second
Parallel Port
Used for scanners and printers
Also called printer port
25 pin model
Also known as IEEE 1284-compliant Centronics
port
44. PS/2 Port
Used for old computer keyboard and mouse
Also called mouse port
Most of the old computers provide two PS/2 port, each for mouse and
keyboard
Also known as IEEE 1284-compliant Centronics port
Universal Serial Bus (or USB) Port
It can connect all kinds of external USB devices such as external hard
disk, printer, scanner, mouse, keyboard etc.
It was introduced in 1997.
Most of the computers provide two USB ports as minimum.
Data travels at 12 megabits per seconds
USB compliant devices can get power from a USB port
45. VGA Port
Connects monitor to a computer's video card.
Has 15 holes.
Similar to serial port connector but serial port
connector has pins, it has holes.
Power Connector
Three-pronged plug
Connects to the computer's power cable that
plugs into a power bar or wall socke
46. Firewire Port
Transfers large amount of data at very fast speed.
Connects camcorders and video equipments to the
computer
Data travels at 400 to 800 megabits per seconds
Invented by Apple
Three variants : 4-Pin FireWire 400 connector, 6-
Pin FireWire 400 connector and 9-Pin FireWire 800
connector
47. Modem Port
Connects a PC's modem to the telephone network
Ethernet Port
Connects to a network and high speed Internet.
Connect network cable to a computer.
This port resides on an Ethernet Card.
Data travels at 10 megabits to 1000 megabits per
seconds depending upon the network bandwidth.
48. Game Port
Connect a joystick to a PC
Now replaced by USB.
Digital Video Interface, DVI port
Connects Flat panel LCD monitor to the
computer's high end video graphic cards.
Very popular among video card manufacturers.
Sockets
Connect microphone, speakers to sound card of
the computer
49. I. Keyboard and mouse: Set up the keyboard right in front of where you’ll sit when you
use the computer, between you and where the monitor goes. The mouse lives to the
right or left of the keyboard, depending on whether you’re right- or left-handed.The PC
keyboard plugs into the keyboard port on the back of the console. The mouse plugs
into the mouse port. Note that the two ports look identical but are different.
II. Monitor: Set the monitor atop your desk, generally back away from where you sit, to
accommodate room for the keyboard.
The monitor plugs into the VGA, or graphics adapter, jack on the back of the console.
The plug goes in only one way.
III. Network: Plug the network, or Cat 5, cable into the network jack on the back of the
console. This is how you connect your PC to a network, or how you connect to a
broadband modem.
iv. Printer: Set up the printer where it’s within arm’s reach of the console. To get the printer
and console talking to each other, you need a cable, either a USB cable or the traditional
printer cable. When you’re blessed with a wireless printer, keep it close enough to the
console to ensure that it’s in range of the signal.
v. USB: USB devices plug into the USB port — any USB port. The USB cable may be
attached directly to the gizmo, or you may have to use (or buy) a separate USB cable.
50. Plug in your computer and all peripherals.
Peripherals include such items as your monitor,
keyboard, mouse and printer, if you have one. In order
to protect your computer, you should use a surge
protector.
Turn on the surge protector. Usually surge protectors
feature a light that will glow when powered on.
Press the power button on your computer or CPU
(Central Processing Unit). These buttons can be
recognized by the power symbol, a circle with a
vertical line intersecting the top of it. Your computer
will boot, and you can begin using it as desired.
51. “using a computer should
enable you to focus on what
you want to accomplish
instead of how to
accomplish”
ALPHONCE ASSENGA
Diploma in computer science and engineering
alphoncesteven@gmail.com