Computer Hardware Maintenance 2010
Computer Hardware Maintenance 2010
Computer Hardware Maintenance 2010
Theory
Notes on
COMPUTER HARDWARE
MAINTENANCE
[As per the Revised Curriculum (Revision 2010) of Unitech
Group for the Advanced Electronics division]
UNITECH GROUP
H.O.: Bakery Junction, Trivandrum. Phone : 0471 2333194
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Printed at
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PREFACE
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CONTENTS
SL.
NO.
TOPIC
Introduction
11
13
Memory Systems
16
22
26
SMPS
30
33
10
35
11
Chipset
36
12
Microprocessors
39
13
50
14
Interconnection Structures
51
15
56
16
62
17
Software
65
18
Operating system
19
DOS Commands
20
LINUX
21
Trouble Shooting
22
23
PAGE
NO.
68
79
References
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Introduction
Simply computer is an electronic machine that helps us to solve problems.
The problems that can be solved with the aid of Computer are wide varied. They
can be problems relating to industry, medicine, education, scientific research, law,
social sciences, arts etc. In fact a computer can solve any problem that can be
solved through step-by-step procedure.
A computer can be defined as an electronic device, which is capable to
hold, retrieve & manipulate information to get the desired output. Computer will
soon play a significant role in the daily functioning of every individual of our
society. In the beginning the computers were very large and costly, so they were
accessible and affordable only to the large corporations, big universities and
government agencies. Advances in semiconductor technology and development
of micro-chips has given rise to such a level of miniaturization, that computing
power of a room sized computer of earlier days is now available on a desk top
computers affordable even to a common individual. These two factors have played
important role in the development of the personal computer (PC), which has
completely invaded our day-to-day life.
A computer is basically a tool to assist man in performing various tasks.
But it differs from other types of tools and machines; the same computer can
perform i.e. many different types of jobs. E.g. computers are used in offices, may
be for word processing or administrative works or accounts; factories - production
planning; education institutions; banking institutions; publishing house; arts and
animation
studios;
advertising
agencies;
architects;
airlines
and
railway
reservations; military and police; doctors and hospitals, The ability to do different
jobs on the same machine distinguishes computers from other machines.
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Computers were invented as a result of mans search for fast and accurate
calculating devices. The earliest device that qualifies as the digital computer is the
ABACUS. This device permits the user to represent numbers by the positions of
beads on a rack.
In the 19th century Charles Babbage (father of modern digital computer),
Professor at the Cambridge University invented the Differential Engine and the
Analytical Engine the principle of which has been the fundamentals of modern
digital computers.
COMPUTER GENERATION
After the II World war rapid developments took place in the growth of
computer in five distinct phases known as the Computer Generation.
First Generation (1942-1955)
The first generation computers were the voluminous computers with large
frame. ENIAC (Electronic Numerical Integrator and Calculator) was the first all
electronic computer.
It was developed at MOORE School of the University of Pennsylvania in
USA by a team led by Professors J.P. Eckert and J.W. Mauchley.
It was
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transistors were smaller in size. Use of transistors reduced the size of computers,
increased its speed and also minimized power consumption.
Third Generation (1964-1975)
The third generation computers were introduced in the year 1964. During
this period transistors were replaced by the Integrated Circuits (I.C.s). Each of
these I.C.s consisted of number of circuits consisting of transistors and capacitors
fabricated in a single chip of silicon. With the introduction of I.C.s computers
processing speed as well as its storing capabilities improved.
Fourth Generation (1975 Onwards)
Initially, I.C.s contained only 10 to 20 components. Which were named
Small Scale Integrator (S.S.I.). Later hundreds of components was integrated into
one chip which was called Medium Scale Integration (M.S.I.).
Later it was
possible to integrate over 30,000 components into one chip called Large Scale
Integration (L.S.I.).
In this fourth generation we have Microprocessors as the brain of
computers. We are now in the Fourth Generation of Computers.
Fifth Generation (Yet To Come)
Scientists are now at work on the fifth generation of computers, which is not
yet a reality. They aim to bring out machines with genuine I.Q., the ability to
reason logically and with real knowledge of the world.
Classification of computers
Generally computers are classified as: Microcomputers, Minicomputers,
Mainframes and Super computers. With the development in technology, the
distinction between all the computers is becoming blurred.
Microcomputers
A Microcomputers Central Processing Unit (CPU) is a microprocessor. The
first microcomputers were built around 8-bit microprocessor chips. (That is, the
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chip can retrieve instructions/data from storage, manipulate, and process an 8-bit
data at a time or that the chip has a built in 8-bit data transfer path.). Nowadays
there are microcomputers with 32-bit or higher microprocessor chips.
Minicomputers
Initial minicomputers were built around 8 and 12 bit machines. But by
1970s almost all the mini computers were 16 bit machines. With the advancement
in technology, the speed, memory size and other characteristics developed. The
minicomputer was more powerful machine, which could be used in variety of
applications and could support business applications along with scientific
applications. The minicomputer was used as a multi-user system, which can be
used by various users at the same time.
Mainframe computers
Mainframe computers are generally 32-bit machines or on the higher side.
These are suited for big organizations to manage high volume applications.
Mainframes are also used as central host computers in distributed system.
Supercomputers
These are amongst the fastest machines in terms of processing speed and
use multiprocessing techniques where a number of processors are used to solve a
CPU
problem. These are mainly used for weather forecasting, remote sensing, image
processing, etc.
Input Unit
Main Memory
Output Unit
ALU
Control Unit
Secondary
Memory
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Data Flow
Control Flow
PERIPHERAL DEVICES
Input Devices
These are the devices, using which user enters the data and the program into
computers storage. Most commonly used input devices are Mouse, Keyboard, and
Scanner etc.
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KEYBOARD
Keyboard is a standard input device.
available that can be attached to the IBM PC/XT/AT. The 84/101 keys keyboard
contains English letters, ten special function characters (F1 to F10), three special
keys (Ctrl, shift, Alt.), three shift lock keys (Caps lock, Num lock and scroll lock)
and several cursor or numeric keypad keys. The keyboard cable is approximately
6 ft. long and coiled like a telephone cable. It is connected to the keyboard at one
end and to a 5 pin DIN connector at the other end.
connector ensures that the keyboard can be connected only in one direction.
There are two types of keyboards. 84 keys keyboard (PC/XT) & 101/104 Keys key
board (PC/AT).
The types of key switches used are:
1. Capacitive switches
2. Hall effect switches
3. Carbon contact
Pin
No.
Description
Description
Keyboard
Clock
Keyboard Data
Keyboard
Data
N/C
N/C
Ground
Ground
+5V DC
+5 V DC
Keyboard
Clock
N/C
4. Hard contact.
Key board signals are:
4. Ground
10
Pin
No.
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XT/AT Switch
Some keyboards have a switch on the rear side viz. Which one can select
MOUSE
It is a digitizing device capable of sensing the position of every desired
point.. The cursor on the monitor follows the movement of the mouse.
DB-25F
25 PIN
WIRE NAME
SHELL
PROTECTIVE
GROUND
RECEIVE DATA
TRANSMIT DATA
7
8
6
5
4
5
6
7
RTS
CTS
DSR
SIGNAL GROUND
20
DTR
DETAILS
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DATA TERMINAL
READY
11
WIRE NAME
DATA
RESERVED
GROUND
+5V SUPPLY
CLK
RESERVED
CHASIS
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touching the ball. At the end of each roller there is a slotted wheel formed by
perforating the edges of the wheels with tiny holes. On one side of the holes there
is an LED and the other side a photodiode or a phototransistor is present to
function as a photo sensor. When the mouse is moved, the ball rotates and the
rollers rotate the slotted wheels. The light emitted by the LED is alternatively
blocked and allowed because of the slots. Accordingly the photo sensor generates
a series of pulses. The opto mechanical mouse has longer life and better reliability.
But it needs periodic cleaning to remove dust and dirt.
3. Optical mouse:
In optical mouse, there is no ball or rollers. A special mouse pad with a grid
is used. The mouse movement is tracked by LEDs and Light-sensitive transistors.
Though expensive, an optical mouse is desirable because of its better accuracy
and higher reliability. There are no moving parts and practically no maintenances
is needed.
A mouse has two or three buttons. The function of each button is defined by
the software. When a button is pressed, the mouse transmits a signal that is
interpreted by the mouse driver. The action taken by a system depends on the
operating system and application program. There are 3 gestures associated with
mouse: Single click, Double click and Drag.
.
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SCANNER
So we have looked at two most common input
devices, key board and mouse, key board is most
suited for entering and editing textual data, Mouse is
best suited as pointing devices in Graphical User
Interface such as MS Windows and for freehand
drawing jobs
But, if you have some existing photograph and you want to transfer it in to the
computer, then none of the above input devices are useful for this purpose, you
need another input device called Scanner for this.
Scanners are the best choice for transferring existing graphical images such as
photograph, logo etc. in to the computer. Using a scanner one can quickly and
easily bring existing images in to the computer.
Once these images are scanned and brought in to the computer one can include
them in to documents, print them or edit them with some image editing software
such as Photoshop, Corel Photo Paint etc.
Scanners are also useful for OCR (Optical Character Recognition) work.
Using OCR software one can scan existing text documents in to the computer and
then convert them in to a format that the word processing software such as MSWord can edit. It is also useful with the fax cards. As the fax cards do not have any
facility to get existing documents in to the computer, one can use the scanner to
scan and get the documents in to the computer for faxing them
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OUTPUT DEVICES
These are the devices, using which user get the output from the computers, in the
form of hard copy and Soft copy. The output form the Monitor is called Hard copy
and the output form the Printer is called Soft copy. The output devices are Monitor,
Printer, and Speaker etc.
MONITORS
The main display unit in computer is the monitor. Now CRT monitors, LCD
monitors are available with different screen sizes.14, 15, 17 etc.Screen
size is commonly measured diagonally.
Power switch
Brightness control
Contrast control
Vertical hold
Horizontal hold
Focus
Vertical size
Horizontal shift
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Vertical linearity
Vertical phase
Monitors are also available with touch screen technology, Plasma screen
etc.
PRINTERS
Printers are the most commonly used output devices to produce printouts of
results, programs and data. In impact printers electromechanical mechanisms are
employed to cause hammers or pins to strike against a ribbon and the paper to
print the text.
Print
To
Dot matrix
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An Epson MX-80
INKJET PRINTERS: These printers use a Non Impact approach to produce a
character. It is quiet in operation as it is a non-impact printer. Ink-jet
printers use a variety of approaches to print a character. In one of
the approaches a voltage causes a piezo electric crystal to send a
pressure wave through an ink chamber. When the pressure
reaches the tip of the nozzle, it forces a drop of ink to move straight
to the paper. The print head employ multiple nozzles just as
multiple pins in a dot matrix print head.
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LASER PRINTERS
These are non-impact page printers. Two types of Laser printers are
available. Post script & Non-post script. These are printer languages used to make
characters.
Post script is from Adobe Inc. and non post script is from HP.
Characters are developed using mathematical equations in post script and using 0
& 1 in non post script, and is stored in a ROM.
Coronas
Toner unit
Fuser Unit
1000V power supply is used to charge the paper, 40V for motors and + 12V
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beam of light with high intensity. This section consists of diodes & mirrors. The
laser beam is produced by the lasing diode and then split into two beams. These
are given to a rotating scanning mirror. This rotating beam is given to the rotating
drum. It is a metallic drum made of Aluminum.
CORONAS
It is a metallic container with a thin metallic wire, which has high melting
point. One end of this wire is connected to an electrode and the other end is
terminator. A high voltage of 1000V is applied to this electrode. Two different
coronas are used in Laser printers. They are Charger & Transfer. The charger
corona is placed above the drum and it charges the drum. The transfer corona is
on the paper path to charge the paper.
TONER & DRUM ASSEMBLY
The toner is a powder, which is a mixture of carbon, iron and plastic. This
toner is placed in a separate container with an outlet, which comes in contact with
the drum. Some printers like HP having disposable toner called toner cartridge.
PAPER TRANSPORT MECHANISM
This has a tray, which can hold around 200 sheets. A paper pickup roller
and a paper feed roller. These are used to feed the paper into the printer.
FUSER ASSEMBLY
Its function is to melt the plastic in the toner and press the image into the
paper surface. This assembly consists of a pressure roller and a heating lamp to
heat the toner around 200 degree Celsius.
Working of laser printer
`
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The text or images are down loaded from the computer to the printer
memory through the parallel ports. The control circuitry in the printer converts it
into full lines. These lines are converted again into dot information and send to the
scanning unit for writing image into the drum. Then the paper is inserted between
the drum and coronas. The image from the drum is transferred to the paper when
the paper is attached to the lower section. The remaining toner is removed from
the drum by cleaning pads and fresh charge is placed on the drum for next image.
The paper is then fed to the fuser assembly, which will melt the toner and press it
to the paper through pressure roller.
Printer Controls
The following discussion summarizes the most common button controls
available for printer systems.
On-line:- The on-line button switch connects and disconnects the printer
from the computer system. When in on-line mode (often indicated by the
on-line light being lit), the printer is connected to the computer system and
able to receive information from it. When the printer is off-line (indicated by
the on-line light being out), the printer is disconnected from the computer
system and ignores any information received.
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Form-feed: -This button switch, when pressed, advances the paper from its
current location to the top of the next page. The new position is established
as the top of form (beginning of a new page). On printers, which support
single sheet paper, this prints a single page of paper.
SPEAKERS
Speaker is also an output device. It is used for hearing sound. It has a
power connector for 230v/110v supply AC. Motherboards Audio line-out (lime
colour) provides signal to the speaker. Advanced sound cards will give better
experience of sound with 5.1, 7.1 sound systems.
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1) The Memory that is directly accessible by the microprocessor is called the main
memory or the primary memory. It includes RAM and ROM. In the earlier
computers, core memory was used as the primary memory. Where in both
program and data were stored. In modern computer semiconductor memory is
used as primary memory
2) External Storage devices or mass storage devices, which are used for storing
large resumes of information and programs, are called Secondary Memory.
It includes Hard disks, CD ROM,DVD ROM, Floppy disks and Flash memories
( pen or Thumb drives) etc.
Primary Memory
(ROM)
ROM
PROM
UVEPROM
MM
EPROM
SDRAM
DDRAM
EEPROM
Flash ROM
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MEMORY SYSTEM
Memory in a computer system is required for storage and subsequent
retrieval of instruction and data. A computer system uses variety of devices for
storing these instructions and data, which are required for its operations.
Volatile and non-volatile memories: The memory, which loses its contents when
the power source is removed, is known as volatile memory. The memory, which
holds the contents even when the power source is removed, is known as nonvolatile memory.
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main memory. It stores some of the content of the main memory, which is currently
in use.
Cache memory is sometimes described in levels of closeness and
accessibility to the microprocessor. An L1 cache is on the same chip as the
microprocessor. (For example, the PowerPC 601 processor has a 32 kilobyte
level-1 cache built into its chip.) L2 is usually a separate static RAM (SRAM) chip.
When the processor needs to execute an instruction, it looks first in its own data
registers. If the needed data isn't there, it goes to the L1 cache and then to the L2
cache. If the data isn't in any cache, the CPU calls out to the main RAM. It might
not even be there, in which case the system has to retrieve it from the disk.
Intel Corp.'s Pentium III processor has 32KB of L1 cache on the processor
chip and either 256KB of L2 on-chip or 512KB of L2 off-chip. The L2 cache on the
CPU chip can be accessed four times faster than if it were on a separate chip.
Indeed, Intel will introduce Level 3 (L3) cache in its 64-bit server
processors, called Itanium. The 2MB or 4MB cache will connect to the processor
over a bus that runs as fast as the processor - 800 MHz.
ACCESS MODES
A memory is considered to consist of various memory locations. The
information from these locations can be accessed in the following ways.
Random Access: In this mode any memory location can be accessed in any
order in the same amount of time. Semiconductor memories, which generally
constitute main memory uses this method.
Sequential access: In this method, the locations can be accessed in pre-defined
sequences only. Magnetic tape uses this type of access. Here different locations
are accessed in different amount of time.
Direct access: In this case the information is accessed neither randomly nor in
sequence but something in between. A separate read/write head exist for a track
and on a track the information can be accessed serially. Magnetic disks use this
semi-random mode of operation.
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DDR RAM
Single Sided
28
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RAM Double Sided
It is used to read a
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This BIOS software is in some regards like other software. There are newer
versions available that contain updates, enhanced, features, new features, and
bug fixes. It is possible to install newer BIOS versions and upgrade, but the
process is different from upgrading regular software that's installed on your
computer. The BIOS software is not stored on the hard drive, but in a chip on the
motherboard. To erase the software on the chip and program it with a newer
software version you need to use a special program called a flash utility, and the
process of performing the upgrade is called flashing the BIOS.
Support for newer processors - The BIOS allows the motherboard to accept
processors up to a certain speed. Since you got the computer, the top
speed of the processor type your computer accepts has increased. You
decide to replace your processor with a faster one, but the BIOS does not
recognize it or does not have the right settings. Upgrading the BIOS can
resolve this problem.
Support for bigger hard drives - The BIOS allows the motherboard to accept
hard drives up to a certain size. Since you got the computer, the maximum
size for hard drives has increased. You decide to install a newer and bigger
hard drive, but the BIOS does not recognize it or only recognizes part of the
drive. Upgrading the BIOS can resolve this problem.
Bug fixes - The BIOS contains certain features and options, but one of them
does not function properly or not at all. Since you got the computer, the
manufacturer has recognized and corrected the problem with a new BIOS
version. Upgrading the BIOS can resolve this problem.
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Note: Please keep in mind that the following steps are an example to help you
understand how the process works. However, your motherboard and BIOS version
are most likely different from mine and you will have to adjust your steps,
download files, and command line switches accordingly. Please exercise caution
when flashing your BIOS and stop and ask for help if you are not certain.
Reboot your machine and press the appropriate key to enter your BIOS. Typical
keys to access the BIOS are (by manufacturer):
AMI - F1, Del, Ctrl-S
AST - Ctrl-Alt-Esc
Award - F1, F2, Del, Ctrl-Alt-Enter
Compaq - F10
Phoenix - F2, Ctrl-Alt-Esc, Ctrl-Alt-R, Ctrl-Alt-Ins, Ctrl-Alt-Q, Ctrl-Alt-F1, Ctrl-Alt-+,
Ctrl-Alt-IBM - PS1 Ctrl-Alt-I
SECONDARY STORAGE
Secondary storage devices are used to store the data and programs
permanently for future use. A disk, like a cassette tape, is a reusable storage
device that holds information, such as programs and data in files. The amount of
space on a disk is measured in bytes. The information stored on a disk is not
deleted when you turn off your computer. (It is deleted on RAM).
There are two kinds of disk drives Hard disk drive and Floppy disk drive. A
hard disk drive contains a non-removable disk that is built into your system. You
can store large amount of information on hard disk in one place, instead of storing
it on many floppy disks. A floppy disk drive holds a removable floppy disk, which
has less storage capacity than a hard disk. The read /write process is very fast on
the hard disk drive than on a floppy disk drive.
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assigned to it so you can tell your system where to find instructions, data or
informations. Normally the floppy disk drives are called A drive or B drive while
the hard disk is called C drive. Floppy disk can be carried any where by the user,
while the hard disk is fixed and cannot be removed by the user.
HARD DISK
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minimum of 1024 Bytes of space while on hard disk it takes minimum of 2048
bytes of space.
On a standard DSDD (Double Sided Double Density) floppy disk there are
80 tracks ( 40 tracks on each side with density 48 T.P.I.) divided into 9 sectors, so
the total capacity is 2 sides x 40 tracks x 9 sectors x 512 bytes = 360 Kilobytes.
While on a D.S.H.D. (Double Sided High Density) floppy disk there are 160 tracks
(80 tracks on each side with Density 96 TPI) divided into 15 sectors, so the total
capacity is 2 sides x 80 tracks x I5 sectors x 512 bytes = 1.2 Mega Bytes.
Bits & Bytes
The binary digits are called as Bits. A BIT represents either 0 or 1. A
character is coded using combination of 8 Bits. When eight bits are combined
together, it is known as a BYTE. It is equivalent of one character. A character or
number is represented by one byte.
eg : Using ASCII code capital letter A is represented in computers as 01000001.
8 bit
=1 byte
1024 bytes
=1 kilobyte
1024 kilobytes
=1 megabyte
1024 megabytes
=1 gigabyte
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2.
3.
Pulse width modulation (PWM) which compares the sampled output with fixed
reference and it adjusts the pulse width of the switching element to get fixed
output.
LINE
FILTER
BRIDGE
RECTIFIER
SWITCH
RECTIFIER
& FILTER
SMT
+12V
STARTER
-12V
PWM
+5V
Vref
-5V
GND
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PGS
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decreases. Output voltage drops back to its desired value. The output voltage
remains regulated
Two Types of SMPS
AT (Advanced Technology) --12 Pin
ATX (Advanced Technology Extended) -- 20 Pin / 24 Pin
AT Connector
Red
+5 v
Black
Ground
Red
+5 v
Black
Ground
Red
+5 v
Blue
Yellow
-12 v
+12 v
Red
+5 v
White
Black
Black
-5 v
Ground
Orange
Ground
ATX Connector
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+5 v
+5 v
+5 v
+12 v
+5 v
Yellow
Red
Voilet
Red
-5 v
+5 v
Gnd
+5 v
Grey
White
Gnd
Black
Black
Gnd
Red
Black
Gnd
Black
+5 v
Gnd
+3.3 v
+3.3 v
Red
Black
Green
Gnd
Power
On
Hardware
Black
Black Computer
Gnd
Maintenance
Orange Blue
-12 v
Orange Orange
+3.3 v
+12 volt supply: The main function of the +12volt power is to run disk drive
motors as well as the higher output processor voltage requirements in
some of the newer boards +12volts supply is use by any cooling fans in the
system.
-5Volt Supply: The -5V signal is directly routed to the ISA bus pin B5 for use
by add-on cards. In earlier floppy drive controller cards; the analog data
separator circuit used -5V.
+3.3 Volt Supply: This supply voltage does not appear of the original XT-AT
or Mini- XT compatible power supplies. Starting with the ATX design in 1995
any system with ATX compatible power supplies include a 3.3-volt supply line
from the power supply to the motherboard. Most CPUs and DRAM use
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3.3volts, as well as some PCI adapter cards. All high sped PCI adapter cards
to use 3.3 volts for all communications with the PCI Bus.
+5VB: (+5 V , Standby mode): The +5VSB line is a +5 volt supply line that
is active any time the AC power input is a active regardless of whether the
system is turned on the purpose of their supply line is to power standby
circuitry ,such as the PS-ON circuit the wake-on-LAN and remote-ring-on
circuitry.
MOTHERBOARDS
The motherboard is the large circuit board inside the computer's case. It's
sometimes called the system board, the logic board, the baseboard, or less
commonly, the planar board. Everything connected to the computer system, plugs
either directly or indirectly into the motherboard.
The CPU, or Central Processing Unit, referred to as the 'brain' of a
computer. The CPU is placed on the motherboard, and if it can be called the brain
of the computer then the motherboard is truly the central nervous system.
The motherboard contains the CPU, the BIOS ROM chip (Basic Input /
Output System), and the CMOS Setup information. It has expansion slots for
installing different adapter cards like the video card, sound card, Network Interface
Card, Modem etc.
This circuit board provides a connector for the keyboard as well as housing
of the keyboard controller chip. It has RAM slots for the system's Random Access
Memory (SIMMs or DIMMs), and provides the system's chipset, controllers, and
underlying circuitry (BUS system) to tie everything together.
The motherboard, more or less, in a computer, it defines the computer type,
upgradeability, and expansion capability.
TYPES OF MOTHERBOARDS
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Non-Integrated Motherboards
Non-Integrated Motherboards have assemblies such as the I/O Port
connectors (serial and parallel ports), hard drive connectors or paddleboards,
floppy controllers and connectors, joystick connections etc. installed as expansion
boards. This takes up one or more of the motherboard's expansion slots and
reduces the amount of free space inside the computer's case. Hence, the
individual motherboard is relatively cheap to produce but, because of the cost of
manufacturing, testing, and installing the expansion boards separately, there's an
added cost to the computer system.
However, if something should go wrong with the individual assemblies, such
as a bent or broken pin in a connector, or a defective controller chip etc., replacing
the individual expansion card at a relatively minor cost can cure the problem.
Most of the older motherboards were Non-Integrated. Some of the later
system boards began to integrate some of these assemblies right onto the circuit
board.
Integrated Motherboards
Integrated Motherboards have assemblies that are otherwise installed as
expansion boards, integrated or built right onto the board. The serial and parallel
ports, the IDE and floppy drive, and joystick all connect directly to the
motherboard. This is now standard on any latest model 486 and above. It tends to
free up some space inside the case and allows for better accessibility and airflow.
The systems are cheaper to produce because there's less material
involved, less installation, and testing can all be done at the same time. They are
more expensive to repair because, if the problem is with a controller failure or
broken pin, it means a new motherboard should be needed (and, of course,
because of the added assemblies, the motherboard can be more expensive than
its non-integrated counterpart).
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MICRO PROCESSOR
AGP
VGA
GMCH
Computer Hardware
(NORTH BRIDGE)
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CLOCK
RAM 1
RAM 2
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BIOS
Audio
Codec
ICH
(SOUTH BRIDGE)
IDE 0
IDE 1
RTC
PS/2 Keyboard
P
C
I
1
SIO
FDD
LPT
COM 1
Chipset
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P
C
I
2
P
C
I
3
P
C
I
3
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i.
ii.
iii.
iv.
MICROPROCESSORS
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This is
4. 80486:80486 DX - The important thing about this chip is that it has a built-in
math co-processor and a 8 KB of internal cache memory. These two
improvements has made the 486 CPU very fast compared to the 386
processor. Like 386 DX, the 486 DX chip also has both internal and external
32-bit data bus and 32 bit address bus, which can address 4 GB of physical
memory. Most of the 486 motherboards provide additional 256 KB of external
cache memory. This chip is available in the speed range from 20 MHz to 50
MHz.
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80486 DX2 - These are called "clock - doubled processors. The reason is
that a 66 MHz DX2 processor works internally at the clock speed of 66
MHz, but communicates with the external world at the clock speed of 33
MHz.
80486 DX3 - It is a clock tripled version of 486 chip and is called "blue
thunder" or 486 DX3. A 25 MHz clock tripled 486 DX3 will work at 75 MHz
internally.
80486 DX4 - This DX4 version of the 486 processor works internally four
times the speed than the speed at which it work externally. A 25 MHz 486
DX4 will work at 100 MHz internally, whereas it will communicate with the
external devices at the 25 MHz clock speed.
5. PENTIUM:This processor has external 64-bit data bus but internally it is 32 bit.
The address bus is 36 bit and can access 4 GB of physical memory. The
Pentium processor has twin data pipe line, which feeds two instructions
together to the processor. This ability is called `Super-scalar Architecture and
the use
of
internal cache, one for data and the other for program instructions.
PENTIUM PRO
Pentium pro is designed for server applications. It runs at speeds
around 250 MHz in a 32-bit operating system. Its dynamic execution property
uses random processing to get output in least time.
PENTIUM MMX
This version of Pentium adds three new features:
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Speed
233MHz to 400MHz
L1 cache
32KB
Layout
SEC
(Single
Edge
Contact)
8080
DATA
ADDRE
YEAR
BUS
SS BUS
(In bits) (In bits)
1974
8
8
6000
8086
1978
16
20
5 to10
29000
8088
1979
20
4.77
29000
80286
1982
16
24
8 to12
34000
80386DX
1985
32
32
16 to 33
275000
80386SX
1988
32
24
16 to 20
275000
486DX
1989
32
32
25 to 50
1.2million
486SX
1991
32
32
16 to 33
1.185 million
487SX
1991
32
32
16 to 33
1.2 million
486DX2
1991
32
32
33 to 66
2million
CHIP
SPEED
(In MHz)
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No. OF
TRANSISTOR
49
486DX4
1992
32
32
75 to 100
2.5 million
Pentium
1993
32
32
60 to 166
3.3 million
Pentium pro
1995
64
32
150 to 200
5.5 million
Pentium II
1997
64
64
233 to 300
7.5 million
1998
64
64
400 to 600
7.5 million
Celeron
1999
64
64
400
1700
to
7.5 million
Pentium III
1999
64
64
350
1200
to
Pentium
xenon
1999
64
64
350
1000
to 9.5 million
Pentium 4
2000
64
64
Intel Xeon
2001
64
64
From 1400
Pentium
xeon
II
III
9.5 million
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Instruction set: An instruction set is a collection of all the instructions a CPU can
execute. A CPUs processing power is measured in Million Instructions Per
Second (MIPS).
Different Control Signals of Microprocessor
1. Memory Read: Output signal from the microprocessor; indicates that the
microprocessor wants to read from the memory.
2. Memory Write: Output signal from the microprocessor; indicates that the
microprocessor wants to write into the memory.
3. I/0 Read: O/P signal from the microprocessor; indicates that the
microprocessor wants to read the data from an input devices.
4. I/0 Write: Output signal the microprocessor; indicates that the
microprocessor wants to send data to an output device.
5. Interrupt: This is an input signal to the microprocessor from the interrupt
controller.
6. INTR: When any interrupt is given to processor it goes to interrupt controller
then this interrupt logic given an INTR signal to microprocessor, the
microprocessor gives an interrupt acknowledgement signal or INTA. Then
interrupt signal give to microprocessor.
7. INTA(Interrupt Acknowledgement): This is an output signal from the
microprocessor, sent in response to the interrupt signal.
8. Reset: This is an input signal to the microprocessor. This is generates by
the Hardware under two conditions.
1) When the computer power is switched on
2) When manual reset is performed by the Operator.
9. Ready: This is input signal to the microprocessor. This signal synchronizes
the microprocessor with the memory (or I/O devices) so that slower
memories (or I/O devices) can be interfaced to the microprocessor.
10. Clock: This is an input signal to the microprocessor. The frequency of this
signal decides the operating speed of the microprocessor. Each
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INTERCONNECTION STRUCTURES
A computer consists of three basic components.
CPU
Memory and
Input/output components
To exchange data among these three components, we need to have an
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modules. The number of lines in a data bus is called the width of data bus. A data
bus width limits the maximum number of bits, which can be transferred
simultaneously between two modules.
The address bus is used to designate the source of data for data bus.
For reading or writing any information on to memory CPU need to specify the
address of a particular location. The address bus supplies this address. The
width of the address bus specifies the maximum memory supported by a
system. The control bus is used for transmission of commands and timing
signals between the system modules. Some of the controls signals are for: bus
request, bus grant, providing
clock signals, providing reset
signals, reading/writing to I/O
devices or memory etc.
EXPANSION BUS
The expansion bus is the
backbone of the computer system.
To add any device to the system,
other
than
motherboard,
what
we
is
on
need
the
the
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coloured expansion slots with 62 pins. This bus was originally designed to transfer
8 megabits per second (Mbps). This had 8-bit path, which was compatible to 8085,
and 8088 CPUs. When 80286 was released there became a need for 16-bit cards.
ISA was modified to allow 8-bit or 16 bit adapters.
EISA Bus: Extended Industry Standard Architecture. It is a 32-bit bus.
This
supports the ISA. It has a height double that of ISA. The edge connector of the
EISA adaptor is longer than the connector on the ISA connector. EISA runs at
8Mhz and can transmit 32 bit at a time. This supports 32-bit 80386 processor.
EISA cards are configured using software. The manufacturers of the card usually
provide a software utility for this purpose.
MCA: IBM introduced Micro Channel Architecture. It supports 32-bit processors. It
operates at 10 MHZ and the data transfer rate is 16 Mbps or 32 Mbps. It is
configured using software.
VESA BUS: Local bus is designed to communication devices with CPU at the
speed CPU capable of. One such bus is the VESA Local Bus or VLBUS. VESA
stands for Video Electronics Standard Association. It could transfer 32-bits of
information at a time and ran at a speed of 40 MHz. It was originally designed for
Video cards. It was later used for hard drive controllers and network cards. VESA
bus had problems with bus speeds in excess of 40 MHz.
PCI: PCI stands for Peripheral Component Interconnect or Interface. It offers 32
bit or 64 bit path and it can support up to 10 devices and operates with a speed
of 60 to 66 MHz. Most new PCI cards are software configurable and usually
support the new Plug and Play standard to automatically configure the card.
PCMCIA: It stands for Personal Computer Memory Card International Association.
It is a new type of bus mainly used for notebook and laptop computers.
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Expansion slots
Motherboard alone rarely offers all the features that you need for your
computer. You can easily add other devices to the motherboard by plugging them
in to expansion slots (or bus slots). There are five different architecture to be
familiar, with ISA, PCI, PCI Express, AGP, USB, and AMR.
PCI Express
PCI Express is a computer expansion card interface format. It was
designed as a much faster interface to replace PCI, PCI-X, and AGP interfaces for
computer expansion cards and graphics cards. It is created in the year2004 by
Intel
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PCI Express slots (from top to bottom: x4, x16, x1 and x16), compared to a
traditional 32-bit PCI slot (bottom), as seen on DFI's LanParty nF4 Ultra-D
AGP (Accelerated Graphics Port)
The Accelerated Graphics Port is a high-speed point-to-point channel for
attaching a graphics card to a computer's motherboard, primarily to assist in the
acceleration of 3D computer graphics. AGP is often referred to as a 'bus', however
this is a misnomer - a single AGP controller is only capable of controlling a single
device. This is the main reason that almost all mainboards have only a single AGP
slot, although motherboards have been built with multiple independent AGP slots.
AGP is currently being phased out in favor of PCI Express.
An AGP slot (maroon, although the color is usually brown) and two PCI slots
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USB
The universal serial bus (USB) is a well established architecture that
allows you to add devices outside of the PC. The devices can also be installed and
removed while the system in running (called hot swapping). Many modern
motherboards will offer two or four USB ports.
AMR
The audio/modem riser, also known as an AMR slot, is an expansion slot
found on the motherboards of some Pentium III, Pentium 4, and Athlon personal
computers. It was designed by Intel to interface with chipsets and provide analog
functionality, such as sound cards and modems, on an expansion card. Physically,
it has two rows of 23 pins, making 46 pins total. Three drawbacks of AMR are that
it eliminates one PCI slot, it is not plug_and_play, and it does not allow for
hardware accelerated cards (only software-based).
ADD-ON CARDS
The ADD-ON cards are used to add other
external features to the computer. The commonly used add on cards are
1. Network card (NIC)
2. Sound card
3. Display Card
4. TV Tuner card
NETWORK CARD
A network card, network adapter or NIC (network interface card) is a piece of
computer hardware designed to allow computers to communicate over a computer
network.A network card typically has a twisted pair, BNC socket where the network
cable is connected, and a few LEDs to inform the user of whether the network is
active, and whether or not there is data being transmitted on it. The Network Cards
are typically available in 10/100/1000 Mbit/s(Mbit/s). This means they can support
a transfer rate of 10 or 100 or 1000 Megabits per second
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Common Manufacturers:
3Com
D-Link
Novell
Intel
Realtek
SOUND CARD
A sound card (also known as an audio card) is a computer expansion card that
can input and output sound under control of computer programs. Typical uses of
sound cards include providing the audio component for multimedia applications
such as music composition, editing video or audio, presentation/education, and
entertainment (games). Many computers have sound capabilities built in, while
others require these expansion cards if audio capability is desired.
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Color
Pink
Function
Lime
green
Analog line level output for the main stereo signal (front speakers or
headphones).
Black
Silver
Orange
DISPLAY CARD
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Connects to:
Motherboard via one of
PCI
AGP
PCI Express
o
o
o
In MDA, CGA, EGA and their related monitors - all use digital signal to
create images on the screen. The problem with this method of interface is that
you cannot vary the hue or intensity of a colour without increasing the number of
signal lines to each gun.
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RED
GREEN
BLUE
GROUND
GROUND
RED GROUND
GREEN GROUND
BLUE GROUND
N/A
GROUND
GROUND
N/A
HSYNC
VSYNC
N/A
COMPUTER SOFTWARE :
Computer software consisting of programs, enables a computer to
perform specific tasks, as opposed to its physical components ( hardware)
which can only do the tasks they are mechanically designed for. The term
includes application software such as word processors which perform
productive tasks for users, system software such as operating systems,
which interface with hardware to run the necessary services for userinterfaces and applications, and middleware which controls and co-ordinates
distributed systems.
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writing
computer
programs
and
software
using
different
System Software
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2. Language Processors.
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2. Memory Management
3. File Management
4. Security Management
5. Command Interpretation
Operating system is mainly classified into two :
1. Command Line Environment (DOS)
2. Graphical Environment (Windows, LINUX etc.)
Disk Operating System (DOS)
File: A file is a primary unit of storage on the computer. It is a collection of information
defined by the user.
Directories: A directory is a special file, which lists a group of files. Storing groups of files
in different directories make files easier to find. The directory you are in is called current
directory. A directory within a directory is called sub directory.
Root directory is the starting point from which all other directories branch out. The
root directory does not have any name. It is represented by a back slash (\).
Drive: A drive is always represented by drive letter. A floppy drive is drive A. If there is a
second drive it is B. Hard disk drive starts from drive C. Depending upon the number of
hard disk and CD Drives present, it is designated from C to Z.
DOS Commands
There are two types of DOS commands, Internal and External
Internal commands execute immediately because they are built into DOS. Therefore,
once DOS is loaded, you do not need the DOS diskette in a drive to use their commands.
Some of the Internal commands are: CLS, DATE, PROMPT, COPY, DEL, MD, REN,
TIME, CD, DIR, PATH, RD, TYPE etc.
External commands are on disks as program files. They must be read from the disk
before they are executed. This means that the disk containing the command must be in a
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drive. Some of the external commands are: FDISK, MORE, ATTRIB, FORMAT, LABEL,
PRINT, XCOPY, DISKCOPY etc.
THE PROMPT: A prompt is simply a message inviting you to enter some command.
Whenever you see the DOS prompt, you may enter a line of input. Since this input
instructs DOS to perform some action, it is called a command.
MS DOS Commands
The copy con or Edit command
Used to create a file
copy con <>File name
^Z to save and exit
OR
Edit <> File name
The del command
To delete a file
del <> File name
The md command
To create a directory
md <>directory name
The rd command
To remove a directory
rd <>directory name
To remove a directory, the directory must be empty. And it can be removed from its
parent directory only.
The cd command
To go to a different directory
cd <> directory name (including path)
The dir command
To list the contents of a directory
dir
To list the contents page by page
dir/p
To list the contents column by column
dir/w
The copy command
To Copy a file
copy <> source file <> destination
The move command
To move a file
move <> source file <> destination
The ren command
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To rename a File
ren <> old name < > new name.
The attrib command
To change the attributes of a file
attrib <> file name <> attribute.
The more Command
The MORE command is used to pause vertical scrolling
on the display screen after each screen. An indication that more
text is to be displayed is given by the messageMORE that
appears on the last line of the screen. You can press any key to
display the next screen of information.
However, if you want the scrolling to stop wherever you
want it to, CTRL-S is the only choice.
The type command
The command displays the contents of standard text (ASCII) files
on your screen. The general form of the TYPE command is
type filename
The contents of the file are displayed on the screen. Scrolling of the text takes
place till the last line of the file is displayed followed by the DOS prompt if it contains more
than one screen of data.
The prompt command
A novice computer user may not understand that a C indicates that the computer
the entire path that leads some instruction you may wish to display a prompt that
says Enter a command.
Special characters used soon after the dollar ($) sign are listed
$
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BATCH FILES
A batch file is one that contains a set of DOS commands.
All batch files must have the extension .BAT and they can
contain valid DOS commands (internal or external)
A batch file is an executable file. Just typing its primary
name at the DOS prompt and pressing the Enter key can
execute it.
batch
file
is
given
the
special
filename
Maintenance
Copies files from the source disk that lie within all
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Pointing device: It allows users to point at different parts of the screen. Pointing devices
can be used to invoke a command from a list of commands presented in a menu. They
can be also used to manipulate objects on the screen by:
Bit mapped displays: It is made up of tiny dots called pixels that are independently
addressable and much finer resolutions than character displays. It has the advantage of
graphic manipulation.
Windows: When a section is split up into several independent regions, each one is called
a window. Several applications can display results simultaneously. The user can switch
from one window to another.
Menus: A menu displays a list of commands within an application
Dialog boxes: Dialog boxes are used to collect information from the user or to present
information to the user. Dialog boxes are also used to indicate error messages in the form
of alert boxes.
Icons: Icons are used to provide a symbolic representation of any system/user-defined
object such as file or folder.
Some of the GUI operating systems:
Windows 95, Windows 98, Windows ME, Windows NT, Windows 2000, Windows
2003, Macintosh Toolbox, Linux, etc
COMPUTER VIRUS
A computer virus is a computer program that can copy itself and infect a
computer without permission or knowledge of the user. The original may
modify the copies or the copies may modify themselves, as occurs in a
metamorphic virus. A virus can only spread from one computer to another
when its host is taken to the uninfected computer, for instance by a user
sending it over a network or carrying it on a removable medium such as a
floppy disk, CD, USB drive or by the Internet. Additionally, viruses can
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LINUX An Introduction
History - UNIX
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While the sizes of those computers posed substantial problems, there was one
thing that made this even worse: every computer had a different operating system.
Software was always customized to serve a specific purpose, and software for one
given system didn't run on another system. Being able to work with one system
didn't automatically mean that you could work with another.
It was difficult, both for the users and the system administrators. Computers
were extremely expensive then, and sacrifices had to be made even after the
original purchase just to get the users to understand how they worked. The total
cost of IT was enormous. Technologically the world was not quite that advanced,
so they had to live with the size for another decade. In 1969, a team of developers
in the Bell Labs laboratories started working on a solution for the software
problem, to address these compatibility issues. They developed a new operating
system, which was:
1. Simple and elegant.
2. Written in the C programming language instead of in assembly code.
3. Able to recycle code.
The Bell Labs developers named their project "UNIX." The code recycling features
were very important. Until then, all commercially available computer systems were written
in a code specifically developed for one system. UNIX on the other hand needed only a
small piece of that special code, which is now commonly named the kernel. This kernel is
the only piece of code that needs to be adapted for every specific system and forms the
base of the UNIX system. The operating system and all other functions were built around
this kernel and written in a higher programming language, C.
This language was especially developed for creating the UNIX system. Using this
new technique, it was much easier to develop an operating system that could run on many
different types of hardware. The software vendors were quick to adapt, since they could
sell ten times more software almost effortlessly. Weird new situations came in existence:
imagine for instance computers from different vendors communicating in the same
network, or users working on different systems without the need for extra education to use
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another computer. UNIX did a great deal to help users become compatible with different
systems.
Throughout the next couple of decades the development of UNIX continued. More
things became possible to do and more hardware and software vendors added support
for UNIX to their products. UNIX was initially found only in very large environments with
mainframes and minicomputers (note that a PC is a "micro" computer). You had to work at
a university, for the government or for large financial corporations in order to get your
hands on a UNIX system. But smaller computers were being developed, and by the end of
the 80's, many people had home computers. By that time, there were several versions of
UNIX available for the PC architecture, but none of them were truly free.
Open Source
The idea behind Open Source software is rather simple: when programmers can
read, distribute and change code, the code will mature. People can adapt it, fix it, debug it,
and they can do it at a speed that dwarfs the performance of software developers at
conventional companies. This software will be more flexible and of a better quality than
software that has been developed using the conventional channels, because more people
have tested it in more different conditions than the closed software developer ever can.
The Open Source initiative started to make this clear to the commercial world, and very
slowly, commercial vendors are starting to see the point. While lots of academics and
technical people have already been convinced for 20 years now that this is the way to go,
commercial vendors needed applications like the Internet to make them realize they can
profit from Open Source. Now Linux has grown past the stage where it was almost
exclusively an academic system, useful only to a handful of people with a technical
background. Now Linux provides more than the operating system: there is an entire
infrastructure supporting the chain of effort of creating an operating system, of making and
testing programs for it, of bringing everything to the users, of supplying maintenance,
updates and support and customizations, etcetera. Today, Linux is ready to accept the
challenge of a fast-changing world.
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Linux is free:- As in free beer, they say. If you want to spend absolutely nothing,
you don't even have to pay the price of a CD. Linux can be downloaded in its
entirety from the Internet completely for free. No registration fees, no costs per
user, free updates, and freely available source code in case you want to change
the behavior of your system. Most of all, Linux is free as in free speech: The
license commonly used is the GNU Public License (GPL). The license says that
anybody who may want to do so, has the right to change Linux and eventually to
redistribute a changed version, on the one condition that the code is still available
after redistribution. In practice, you are free to grab a kernel image, for instance to
add support for tele-transportation machines or time travel and sell your new code,
as long as your customers can still have a copy of that code.
Linux is portable to any hardware platform:- A vendor who wants to sell a new
type of computer and who doesn't know what kind of OS his new machine will run
(say the CPU in your car or washing machine), can take a Linux kernel and make
it work on his hardware, because documentation related to this activity is freely
available. Linux was made to keep on running: As with UNIX, a Linux system
expects to run without rebooting all the time. That is why a lot of tasks are being
executed at night or scheduled automatically for other calm moments, resulting in
higher availability during busier periods and a more balanced use of the hardware.
This property allows for Linux to be applicable also in environments where people
don't have the time or the possibility to control their systems night and day.
Linux is secure and versatile:- The security model used in Linux is based on the
UNIX idea of security, which is known to be robust and of proven quality. But Linux
is not only fit for use as a fort against enemy attacks from the Internet: it will adapt
equally to other situations, utilizing the same high standards for security. Your
development machine or control station will be as secure as your firewall.
Linux is scalable:- From a Palmtop with 2 MB of memory to a petabyte storage
cluster with hundreds of nodes: add or remove the appropriate packages and
Linux fits all. You don't need a supercomputer anymore, because you can use
Linux to do big things using the building blocks provided with the system. If you
want to do little things, such as making an operating system for an embedded
processor or just recycling your old 486, Linux will do that as well.
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The Linux OS and Linux applications have very short debug-times :- Because
Linux has been developed and tested by thousands of people, both errors and
people to fix them are found very quickly. It often happens that there are only a
couple of hours between discovery and fixing of a bug.
Linux distributions.
RedHat Linux
SuSE Linux
Mandrake Linux
Knoppix: an operating system that runs from your CD-ROM, you don't need to
install anything.
Ubuntu Linux
Downloadable ISO-images can be obtained from LinuxISO.org. The main
distributions can be purchased in any decent computer shop.
Working with LINUX
In order to work on a Linux system directly, you will need to provide a user name
and password. You always need to authenticate to the system. Most PC-based Linux
systems have two basic modes for a system to run in: either quick and sober in text
console mode, which looks like DOS with mouse, multitasking and multi-user features, or
in graphical console mode, which looks better but eats more system resources.
Graphical mode
This is the default nowadays on most desktop computers. You know you will
connect to the system using graphical mode when you are first asked for your user name,
and then, in a new window, to type your password. To log in, make sure the mouse pointer
is in the login window, provide your user name and password to the system and click OK
or press Enter.
Text mode
You know you're in text mode when the whole screen is black, showing (in most
cases white) characters. A text mode login screen typically shows some information about
the machine you are working on, the name of the machine and a prompt waiting for you to
log in:
RedHat Linux Release 8.0 (Psyche)
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blast login: _
The login is different from a graphical login, in that you have to hit the Enter key
after providing your user name, because there are no buttons on the screen that you can
click with the mouse. Then you should type your password, followed by another Enter.
You won't see any indication that you are entering something, not even an asterisk, and
you won't see the cursor move. But this is normal on Linux and is done for security
reasons.
When the system has accepted you as a valid user, you may get some more
information, called the message of the day, which can be anything. Additionally, it is
popular on UNIX systems to display a fortune cookie, which contains some general wise
or unwise (this is up to you) thoughts. After that, you will be given a shell, indicated with
the same prompt that you would get in graphical mode.
Meaning
Displays a list of files in the current working directory, like the dir
command in DOS
cd directory
change directories
passwd
file filename
cat textfile
pwd
exit or logout
man command
info command
apropos string
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DOS commands
Linux command
<command> /?
cd
chdir
man <command>
cd
pwd
cls
clear
copy
date
del
dir
echo
edit
exit
fc
find
format
mem
mkdir
more
move
ren
time
cp
date
rm
ls
echo
vi (or other editor)
exit
diff
grep
mke2fs or mformat
free
mkdir
more or even less
mv
mv
date
2 ACDSee
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Linux Equivalent/Alternative
K-3D ( http://www.k-3d.org/ )
Wings 3D ( http://www.wings3d.com/ )
Art of Illusion ( http://www.artofillusion.org/ )
Blender ( http://www.blender.org/ )
KuickShow ( http://kuickshow.sourceforge.net/ )
ShowImg ( http://www.jalix.org/projects/showimg/ )
Gwenview ( http://gwenview.sourceforge.net/ )
GQview ( http://gqview.sourceforge.net/ )
Eye of GNOME ( http://www.gnome.org/projects/eog/ )
okular ( http://kpdf.kde.org/okular/ )
Xpdf ( http://www.foolabs.com/xpdf/ )
Evince ( http://www.gnome.org/projects/evince/ )
ePDFView ( http://trac.emma-soft.com/epdfview/ )
KPDF ( http://kpdf.kde.org/ )
Computer Hardware
Maintenance
4 Adobe Audition
Audacity ( http://audacity.sourceforge.net/ )
5 Adobe Illustrator
Skencil ( http://www.skencil.org/ )
Inkscape ( http://www.inkscape.org/ )
Karbon14 ( http://www.koffice.org/karbon/ )
Xara Xtreme for Linux ( http://www.xaraxtreme.org/ )
6 Adobe PageMaker
Scribus ( http://www.scribus.net/ )
10
F-Spot ( http://f-spot.org/Main_Page )
Adobe PhotoAlbum
KPhotoAlbum ( http://www.kphotoalbum.org/ )
digiKam ( http://www.digikam.org/ )
CinePaint ( http://www.cinepaint.org/ )
Adobe Photoshop
Krita ( http://www.koffice.org/krita/ )
GIMP ( http://www.gimp.org/ )
PiTiVi ( http://www.pitivi.org/wiki/Main_Page )
LiVES ( http://lives.sourceforge.net/ )
Kino ( http://www.kinodv.org/ )
Adobe Premier
Cinelerra ( http://cvs.cinelerra.org/ )
kdenlive ( http://kdenlive.sourceforge.net/ )
Jahshaka ( http://www.jahshaka.org/ )
Epiphany ( http://www.gnome.org/projects/epiphany/ )
Opera ( http://www.opera.com/download/ )
Microsoft Internet Explorer
Firefox ( http://www.mozilla.com/firefox/ )
Konqueror ( http://www.konqueror.org/ )
11
Microsoft
HyperTerminal
12
Microsoft Internet
Explorer
13 Microsoft Money
14 Microsoft Office
15 Microsoft OneNote
minicom ( http://alioth.debian.org/projects/minicom/ )
GtkTerm ( http://freshmeat.net/projects/gtkterm/ )
Epiphany ( http://www.gnome.org/projects/epiphany/ )
Opera ( http://www.opera.com/download/ )
Firefox ( http://www.mozilla.com/firefox/ )
Konqueror ( http://www.konqueror.org/ )
KMyMoney ( http://kmymoney2.sourceforge.net/ )
GNUcash ( http://www.gnucash.org/)
Gnofin ( http://gnofin.sourceforge.net/ )
Grisbi ( http://www.grisbi.org/ )
GNOME Office ( http://www.gnome.org/gnome-office/ )
KOffice ( http://www.koffice.org/ )
OpenOffice ( http://www.openoffice.org/ )
BasKet ( http://basket.kde.org/ )
Computer Hardware
Maintenance
79
16
Microsoft Outlook
(Express)
17 Microsoft Powerpoint
18 Microsoft Project
19 Microsoft Visio
20
Microsoft Windows
Media Center
21 Microsoft Word
22 mIRC
23 Mp3tag
24 MSN messenger
Thunderbird ( http://www.mozilla.com/thunderbird/ )
Evolution ( http://www.gnome.org/projects/evolution/ )
Open Office Impress (
http://www.openoffice.org/product/impress.html )
KPresenter ( http://www.koffice.org/kpresenter/ )
KPlato ( http://www.koffice.org/kplato/ )
OpenProj ( http://openproj.org/openproj )
GanttProject ( http://ganttproject.sourceforge.net/ )
Planner ( http://live.gnome.org/Planner )
TaskJuggler ( http://www.taskjuggler.org/ )
Dia ( http://www.gnome.org/projects/dia/ )
Kivio ( http://www.koffice.org/kivio/ )
Freevo ( http://freevo.sourceforge.net/ )
Elisa Media Center ( http://www.fluendo.com/elisa/ )
MythTV ( http://www.mythtv.org/ )
LinuxMCE ( http://www.linuxmce.com/ )
Open Office Writer (
http://www.openoffice.org/product/writer.html )
AbiWord ( http://www.abisource.com/ )
Kword ( http://www.koffice.org/kword/ )
Konversation ( http://konversation.kde.org/ )
KVIrc ( http://www.kvirc.net/ )
BitchX ( http://www.bitchx.org/ )
Xchat ( http://www.xchat.org/ )
ChatZilla! ( http://chatzilla.hacksrus.com/ )
irssi ( http://www.irssi.org/ )
Pidgin ( http://pidgin.im/ )
Kid3 ( http://kid3.sourceforge.net/ )
Pinkytagger ( http://pinkytagger.sourceforge.net/ )
EasyTAG ( http://easytag.sourceforge.net/ )
Cowbell ( http://more-cowbell.org/ )
Audio Tag Tool ( http://pwp.netcabo.pt/paol/tagtool/ )
Mercury Messenger ( http://www.mercury.to/ )
Kopete ( http://kopete.kde.org/ )
aMSN ( http://amsn-project.net/ )
Pidgin ( http://pidgin.im/ )
25 Mudbox
SharpConstruct ( http://sharp3d.sourceforge.net/ )
X-CD-Roast ( http://www.xcdroast.org/ )
Brasero ( http://perso.orange.fr/bonfire/index.htm )
80
Computer Hardware
Maintenance
GnomeBaker ( http://gnomebaker.sourceforge.net/ )
Graveman! ( http://graveman.tuxfamily.org/ )
K3b ( http://www.k3b.org/ )
REFERENCES
Computer Hardware
Maintenance
81
Computer Hardware
Maintenance
UNITECH
Computer Hardware
Maintenance
83