What does A+ Certification mean? The A+ certification is a basic certification that demonstrates proficiency with computer hardware and operating systems (OS). It is governed by nonprofit trade association CompTIA. The A+ certification helps prove the recipient's proficiency with the use of computers and related devices. Techopedia explains A+ Certification Core elements of A+ certification criteria include knowledge of computer anatomy, which is why many experts suggest that those pursuing this credential practice assembling and disassembling a physical computer. Other areas involve operating systems (OS) and knowledge of Microsoft products. Those seeking A+ certification also should be knowledgeable about certain tasks, like booting up a computer with various installed operating systems (OS). In addition to hardware configuration aspects, the A+ test also covers computer data usage elements, such as the basic structure of binary data and various aspects of file input/output (I/O). Test prep materials and other resources showing specific A+ certification test topics are available.

1. A+ certification
(Core hardware)
Pc Maintenance
MADE BY:
MR: Muhammad Ishrat

2. INDEX
MOTHER BOARD
INPUT DEVICES
STORAGE DEVICES
OUTPUT DEVICES
OTHER PERIPHERALS

3. Bit:
The binary digit ‘1’ & ‘0’ is called bit...
Byte:
A combination of ‘8’ bits is called byte...

4. Chart of memory units:
1 nibble=4 bits.
1 byte =8 bits
1 kilo byte=1024 bytes
1 Mega byte=1024 kilo bytes
1 Giga byte=1024 mega bytes
1 Tera byte=1024 giga bytes
1 pita byte =1024 Tera bytes

5. Motherboard
1. CPU
2. RAM
3. ROM
4. BIOS
5. HEAT SINKER
6. PCI Slots
7. SYSTEM BUSES
8. Condenser
9. Ports & connectors
MSI (Medium Scale integrated)

6. 1. Central Processing Unit
(CPU)
1. CPU or central
processing unit is the
main processing unit
2. It determines the
performance of the
computer (processor
speed)
3. Can be said a BRAIN of
computer
4. Currently Pentium Chip
(Processor) are most
popular

7. 2.RAM
1. First Ram was introduced in October 1970
2. One of most important part of computer
3. Random Access Memory RAM stores information
temporarily
4. More RAM in the computer more faster computer
works
5. RAM is in the form of a chip and different vendors
have developed the RAM of different capacities

8. Typically RAM chips reside on memory modules.
Four main types exist.
SIMMs
DIMMs
SODIMMs
RIMMs

9. SIMMs
Single Inline Memory Module
Pins on opposite sides form a single set of
contacts

10. DIMMs
Dual Inline Memory
Module
168 Pins on opposite sides of
the circuit board form
separate connections

11. SODIMMs
Small Outline Dual In-line Memory Module
A much smaller form of memory
Used in Notebook computers and Apple iMac
desktops
In “DDR2” SODIMMS has 200 pins
In “DDR3” SODIMMS has 204 pins

12. RIMMs
RAM bus Inline Memory Module RDRAM
Comparable in size and pin configuration to
DIMM but uses a special memory bus to
greatly increase speed.

13. What are some different types of Random
Access Memory ?

14. Types of Dynamic RAM (DRAM)
SDRAM – Synchronous DRAM
Synchronized to the system clock
DDR SDRAM (Double Data Rate SDRAM)
Transfer data twice for each clock cycle
Rambus DRAM (RDRAM)
Faster than SDRAM chips because they use pipelining
techniques

15. Types of Dynamic RAM
Stores 1’s and 0’s on capacitors
Must be recharged every millisecond, or every one
thousandth of a second
Many different types exist (previous slide)

16. Synchronous DRAM
Resides on DIMMs
Faster than previous DRAM because it is
synchronized with the system clock
Maximum transfer rate to L2 cache is approximately
528 megabytes per second.
Most common choice of Pentiums until recently

17. Double Data-rate SDRAM
Resides on DIMMs
Also known as SDRAM II
Faster than SDRAM because it transfers data twice for
each clock cycle
Commonly used in PCs

18. RAM Bus DRAM
Resides on RIMMs
Uses a pipelining technique to increase speed
RDRAM memory chips work in parallel to achieve a
data rate of 800+ MHz.

19. Static RAM
Often used for Cache Memory
Very fast and reliable because these chips do not have
to be recharged as often as DRAM chips hence the
term “static”
SRAM chips: more expensive than DRAM

20. Static RAM
Cache Memory (Static RAM) helps speed up the
microprocessor.
Cache Memory stores frequently used data and
instructions.

21. Static RAM
 Personal Computers have 2 and perhaps 3 types of
cache memory:
L1 (Level 1) Cache (8KB to 128KB)
L2 (Level 2) Cache (64KB to 4MB)
L2 Advanced Transfer Cache on current
microprocessors (built on the chip)

22. Static RAM
L3 (Level 3) Cache is cache separate from the
microprocessor chip and is on the motherboard.
L3 Cache exists only on computers that use the L2
Advanced Transfer Cache.

23. Static RAM
A computer with L2 cache usually performs at speeds
10 to 40 percent faster than those without cache.
Servers and workstations can have at least 2MB of L2
or L3 cache.

24. SGRAM
Synchronous Graphics RAM
SGRAM is a variant of SDRAM
SGRAM makes use of block-writes to increase video
processing speeds.
SGRAM is single-ported so the CPU cannot write to it
at the same time the image is being refreshed.
SGRAM is used in high-end graphics cards

25. THERE ARE THREE TYPES OF ROM

26. 4.BIOS
1. BIOS: Basic
Input/Output system
is a set of instructions
in ROM
2. Used to start most
basic services of
computer system
3. Computer have more
than one BIOS

27. 5. HEAT SINKER
1. A cooling mechanism
prevent damage to
computer from heat
2. Contains fans and
sinks
3. The CPU, Computer
case, power supply,
some Hard disk,
some adapter cards
need cooling

28. 6. PCI slots
1. Slot is the space
provided on
motherboard used to
increase functionality
of computer
2. There are RAM slots,
AGP slots and
expansion slots.

29. 7. Bus
 a group of wire between two part of hardware
There are three main bus groups
 ADDRESS BUS
 DATA BUS
 CONTROL BUS
2/3 of compter times is used for data transfer therefor the data bus bandwidth is very
important.

30. Data Bus
The Data Bus carries the data which is transferred throughout the system. (
bi-directional)
Examples of data transfers
 Program instructions being read from memory into MPU.
 Data being sent from MPU (Memory Protection Unit/Micro Processing Unit)
to I/O port
 Data being read from I/O port going to MPU
 Results from MPU sent to Memory
These are called read and write operations

31. Address Bus
 An address is a binary number that identifies a specific memory storage
location or I/O port involved in a data transfer
 The Address Bus is used to transmit the address of the location to the memory
or the I/O port.
 The Address Bus is unidirectional ( one way ): addresses are always issued by
the MPU.

32. Control Bus
 The Control Bus: is another group of signals whose functions are to provide
synchronization ( timing control ) between the MPU and the other system
components.
 Control signals are unidirectional, and are mainly outputs from the MPU.
 Example Control signals
 RD: read signal asserted to read data into MPU
 WR: write signal asserted to write data from MPU

33. EXPENSION BUSES:
Expansion buses are also referred to as external buses.
These buses connect the external device such as:
keyboard , mouse , modem , printer , so on to the
processor.
Expansion buses are connected to the system bus.
System buses allows the processor to communicate
with other devices.
we connect a devices with the system unit through a
port on an adopter card.

34. 8. Condenser:
Condensers are typically heat exchanger
which have various design & come in many
sizes ranging from rather small(hand-held)
to very large industrial scale units used in
plant processing.

35. 9. Ports:
The input , output & communication devices are
connected to the system unit through a special device
is called ports.
It is an interface or connecting socket.
it provides a standard way of communication
between the computer & its input & output devices.
Example:
keyboard , mouse , monitor ,printer ,& so on.
Come with a cable & multiple connectors...

36. Connectors are available in 2 types:

37. Male connectors:
It has the set of exposed
pins. Like the end of an
electrical cord you plug into
the socket.

38. Female connectors
It has set of whole pins
like an electrical wall out
to accept the pins on a
male connectors...

39. Types of ports:
A system unit make many ports of
different types
The main types of ports are serial
ports , parallel ports , & usb port.
Most personal computers are at least
one serial port one parallel port & two
usb ports...

40. TYPES OF PORTS

41. Serial port:
A serial port provide a connection for
transmitting data one bit at a time.
The data in serial port is transmit through
a single unit however the serial port consist
on multiple wires the other wire control the
flow of data. The com:
ports(communication ports) on the system
unit is one type of serial port.

42. Parallel ports:
A parallel port provide a connection for
transmitting data eight bit. The device that
are connected to the parallel port have a
data cable with eight parallel separate data
lines. The printer is connected to the
parallel ports the cable use to connect
printer two the computer often have twenty
five pins female connectors.

43. Usb ports:
Usb stands for universal bus. Today it is the most
popular standard port used in pcs.
The usb allows up to 127 devices to be connected to
the bus via a single port.
Today personal computers typically have two or four
usb ports either on the front or on back of the system
unit.
A usb hub is a device which is plugged in to a usb
port on the system unit it contains multiple usb ports
into which you can plugged multiple devices.

44. INPUT DEVICES
Keyboard
Mouse
Scanner
Joystick
Microphone

45. 1. Keyboard
1. The keyboard is used
to type something or
input information to
the computer.
2. Connects to the
system via cable or
wireless connections
3. There are different
designs and models
available

46. 2. Mouse
1. Most common input
device used to give
instructions to
computer
2. Connectivity via
cable or wireless
media
3. Types: Track Ball,
Optical mouse, IR
mouse, Radio wave
mouse

47. 3. Scanner
1. Scanners allow you to
transfer pictures and
photographs to your
computer
2. Used to scan the
images and pictures
3. Using software you
can convert printed
documents into the
text that you can use
in the word processor

48. 4. Joystick
1. Another input device
used to play games
2. Available in many
shapes

49. 5. Microphone
1. Used to give audio
input
2. Important in video
conferencing

50. Storage devices
primary storage
1. RAM
Secondary storage
1. HDD
2.Floppy disk
3. Solid storage devices

51. 1. Hard Disk Drive
1. Hard Disk Drive
HDD is a mechanism
to run disks
2. HD is a fixed media
storage device
3. Data stored
magnetically
4. Mostly internal but
some are external

52. 2. Floppy
1. Floppy disks stores
data magnetically
2. Disk covered by
means of plastic coat
3. Older storage device
having less storage
capacity

53. 3. Solid storage Device
1. Used as external
storage device
2. Works faster than
disks
3. Data stores
electrically and
having USB

54. Output Devices
Monitor
Speakers
Printer

55. 1. Monitor
1. monitor is used to
display the
information on the
screen.
2. Monitors come in
many sizes and
shapes, monochrome
or full colors
3. Today most
computers use LCD

56. 2. Speakers
1. Speaker is the audio
output device
2. Used to listen songs
and other audio
media

57. 3. Printer
1. printer takes the
information from the
PC and transfers it to
the paper of different
sizes
2. There are three basic
types of a printer
such as dot matrix,
inkjet and laser

58. Other Peripheral Devices
Modems
Digital Camera
Sound and Video Card

59. 1. Modem
1. Modem is used for
modulation and
demodulation of data
2. convert data analog to
digital and digital to
analog
3. Can be internal and
external
4. Modems are measured by
the speed which is called
baud rate. The typical
baud rate is 56Kb

60. 2. Digital Camera
1. Device used to take
digital photographs
2. Images stores on the
memory chip of
camera
3. Used in video
conferencing

61. 3. Sound card
1. Sound cards produce
the sound like music
and voice
2. The older cards were
8, 16 and then 32 bits
3. allow output device
to produce audio

62. 4. Video card
1. Alternatively referred
to as a graphics card,
video card, video
board, or a video
controller, a video
adapter
2. It allow a display
device such as
a monitor to display
images from the
computer

63. CPU Packages
Pentium: This processor features 32-bit multitasking
using RISC (Reduced Instruction Set Computer
The Pentium expanded the internal bus to 64 bits and
high-speed internal cache.
Pentium Pro: The Pentium Pro was developed as a
network server processor.
 It was specially designed to support 32-bit network
operating systems, such as Windows NT

64. Pentium II:
 The Pentium II is the Pentium Pro processor with
MMX technology added. The P-II, as it is commonly
referred to, is excellent for multimedia work that
requires support for full-motion video and 3D images
Celeron:
Developed for use in desktop and portable computers,
the Celeron is a low-cost version of the Pentium II
processor.

65. Pentium III:
Pentium III has been the highest-powered processor
in the Intel arsenal. It features 9.5 million transistors,
a 32K L1 cache, 512K of L2 cache, and clock speeds of
450 MHz to 1 GHz.
Xenon:
The Xeon is a network server processor that is capable
of addressing and caching up to 64GB of memory with
its 36-bit memory address bus

66. Pentium 4:
Pentium 4 (P4) processor has clock speeds that
exceed 2 GHz, or about twice the speed of the
Pentium III.
Using the first totally new processor design since the
Pentium Pro.

67. Virtual Memory
Virtual memory is the art of using hard disk space to
hold data not immediately required by the processor;
it is placed in and out of RAM as needed

68. Virtual Memory
In real mode, sometimes called compatibility mode, a
286 emulates the 8086 processor and addresses only
the first 1 MB of memory. This mode is used to
run older software.
Protected mode allows access to all memory on the
system, physical and virtual. In protected mode, a
program can write only to the memory allocated to it,
with specific memory blocks allocated to different
programs.

69. Defining Memory
Nonvolatile and Volatile Memory
ROM: Read-Only Memory (is nonvolatile memory )
RAM: Random Access Memory
RAM volatile memory

70. Motherboard & BIOS
• The BIOS is the PC’s opening act.
• It ensures that the hardware is alive, well, and ready
for the operating system, and then gets the operating
system running
• The BIOS (Basic Input/Output System) is a collection
of software utilities and programs that can be invoked
by the operating system or application software to
perform many hardware-related tasks.

71. MOTHERBOARD & BIOS

72. Remember for BIOS
The BIOS performs three vital functions for the
computer:
Boot the PC.
Verify the configuration data that tells it the internal
and peripheral devices that are supposed to be
connected to the PC.
Provide the interface between the hardware (the
attached devices) and the software (such as the
operating system, device drivers, and application
software).

73. Power-Supply Connectors
AT-Style Connections to the Motherboard
A pair of almost identical connectors, designated P8
and P9, link the power supply to the motherboard
These connectors are seated into a row of six pins and
matching plastic guides, or "teeth," on the
motherboard. The P8 and P9 connectors must be
placed in the proper orientation

74. POWER-SUPPLY CONNECTORS

75. Power-Supply Connectors

76. The following table of power cables shows voltage
values for each of the color-coded wires on P8
and P9
Cable Color Supply In Tolerance
Yellow +12 ±10%
Blue -12 ±10%
Red +5 ±5%
White -5 ±5%
Black Ground N/A

77. ATX Motherboard Connections
The newer ATX main power connection is much
easier to install.

78. ATX MOTHER BOARD CONNECTORS

79. Connections to Peripheral
Hardware
Two standard types of connectors can connect to
peripheral hardware:
Molex connector: This is the most commonly used
power connector. It provides both 12-volt and 5-volt
power. Hard disk drives, internal tape drives, CD-
ROM drives, DVD (digital video disc) drives

80. Mini connector
Most power supplies provide one or more "mini"
connectors
used primarily on 3.5-inch floppy-disk drives. It has
four pin-outs and, usually, four wires
applying power with the connector
reversed can damage
or destroy the drive.

81. Two- and Three-Pin Mini Plugs
A less common type of power connector is used to
connect the fan of a Pentium II or III processor to the
motherboard for power
Also to connect a CD-ROM drive to a sound card, and
to provide power for 3.5-inch floppy disk drives. These
connectors have two or three wires which are usually
red and black or red, yellow, and black.

82. CAUTION
Do not connect power-carrying mini plugs to audio or
data devices such as a CD or a sound card, because
you might damage or destroy those devices.

83. Extenders: are wire sets that have a Molex connector
on each end; they are used to extend a power
connection to a device beyond the reach of the power
supply's own wiring.
EXTENDERS

84. SPLITTERS
Splitters : are similar to extenders, with the
exception that they provide two power connections
from a single power supply connector

85. Uninterruptible power supply
(UPS)
A device connected between a computer and a power
source to ensure that electrical flow is not
interrupted.
UPS devices use batteries to keep the computer
running for a period of time after a power failure. UPS
devices usually provide protection against power and
light as well.

86. Floppy Disk Drives
The most basic input device is the floppy disk drive .
It is perhaps the only computer component that has
retained its original technology.
Other than increased storage capacity and the
adoption of a hard plastic shell .
The floppy disk drive still works essentially the same
way (in terms of cabling and BIOS configuration)
It did 10 years ago

87. Installing floppy disk drives
 Remember :
There are three considerations when installing a
floppy disk drive in a PC .
Media
Physical size:
Capacity:

88. Media
Which diskette sizes has the user been using to back
up data or install software?
 Don’t do the customer a favor and upgrade the
system to a 31⁄2-inch floppy drive when all of his files
are on 51⁄4-inch floppies.

89. Physical size
Three package sizes (also called form factors) for
floppy disk drives exist:
A full-height drive (which is big, bulky, and takes
about two expansion slots) is common in older PCs.
The half-height drive is half as tall as a full-height
drive. It’s the size of one expansion slot on a PC case.
This drive is the de facto standard in use today.
The combination half-height drive fits both a 31⁄2-
inch and a 51⁄4-inch drive into a single half-height drive

90. Capacity
Floppy disks range in their storage capacity.
 Depending on how many sides and the media density
of the disk, 51⁄4-inch floppy disks hold between 360K
to 1.2MB.
Depending on the same variables, 31⁄2-inch disks hold
from 720K to .14MB.

91. Hard Drive
Computer's main storage media device, also called a
"hard disk drive" or abbreviated as "HD" or "HDD".
A hard drive consists of one or more hard disks inside
of air sealed casing
Most hard drives are permanently stored in an
internal drive bay at the front of the computer and are
connected with one ATA / SCSI cable and power cable.

92. HARD DRIVE
Hard Disc

93. Inside Hard drive
Hard disk drives are composed of one or more disks
or platters on which data is stored.
Heads
Cylinders
Sectors per track

94. Heads
The number of heads is relative to the total number of
sides of all the platters used to store data.
If a hard disk drive has four platters, it can have up to
eight heads. The maximum number of heads is
limited by BIOS to 16.

95. Some hard disk drive manufacturers use a technology
called sector translation.
This allows some hard drives to have more than two
heads per platter .
It is possible for a drive to have up to 12 heads but
only one platter .
Regardless of the methods used to manufacture a
hard drive, the maximum number of heads a hard
drive can contain is 16.

96. Tracks & Cylinders
Data is stored in circular paths on the surface of each head.
Each path is called a track.
There are hundreds of tracks on the surface of each head.
A set of tracks (all of the same diameter) through each head
is called a cylinder.
BIOS limitations set the maximum number of cylinders at
1024.

97. Sectors per Track
A hard disk drive is cut (figuratively) into tens of
thousands of small arcs, like a pie.
Each arc is called a sector and holds 512 bytes of data.
 The number of sectors is not important and is not part
of the geometry; the important value is the number of
sectors per track.
BIOS limitations set
the number of sectors
per track at 63.

98. CHS Values
Cylinders, heads, and sectors per track are known
collectively as the CHS values.
The capacity of any hard disk drive can be determined
from these three values.
Figure Cylinders, heads,
sectors per track

99. The maximum CHS values:
1024 cylinders.
16 heads.
63 sectors per track
.
512 bytes per sector.

100. CHS Values
Therefore, the largest hard disk drive size recognized
directly by the BIOS is 504 MB.
Larger drive sizes can be attained by using either
hardware or software translation that manages access
to the expanded capacity without direct control by the
system BIOS.
1024 x 16 x 63 x 512 bytes/sector = 528,482,304 bytes
(528 million bytes or 504 MB)
There are many hard disk drives that are larger than
504 MB

101. Hard Disk Drive Types
Today, there are four types of hard drives, each with
its own method of installation.
ST506
ESDI
IDE/EIDE
SCSI

102. ST506
The very first hard disk drives for personal computers
used the ST-506/412 interface.
It was developed by Seagate Technologies in 1980 and
originally appeared with the 5-MB ST-506 drive.
The ST-506 was priced at $3,000 and had a capacity of
5 MB.
The ST-506/412 was the only hard drive available for
the IBM computer and was the first to be supported
by the ROM BIOS chip on the motherboard.

103. ESDI
The ESDI (Enhanced Small Device Interface) was
introduced in 1983 by the Maxtor Corporation.
This technology moved many of the controller
functions directly onto the hard disk drive itself.
This greatly improved data transfer speeds
Today they are obsolete .
Today they are obsolete.

104. IDE/EIDE
The IDE (Integrated Drive Electronics) drive arrived
on the scene in the early 1990s
IDE quickly became the standard for computers.
It supports the ST-506 standard command set, and its
limited controller functions build directly on the
drive's logic board.
 This results in a much less expensive design. Most new
motherboards have the IDE connections built in; thus,
the chips are part of the board design

105. IDE CONNECTIONS

106. ESDI CONNECTOR

107. IDE/EIDE
Enhanced IDE (EIDE) adds a number of
improvements to the standard IDE drives,
Including:
Increased data throughput.
Support of storage devices other than hard disk
drives.
Up to four IDE devices instead of just two. This
actually allows the BIOS to support two controllers
(each with two drives).
Support for hard disk drives larger than 528 MB.

108. EIDE CONNECTOR

109. Partitioning (partition)
Partitions are logical divisions of a hard drive.
A computer might have only one physical hard drive
(called hard drive ).
Partitions exist for two reasons:
To divide the disk into several drive letters to make it
easier to organize data files. Some users separate data,
programs, and operating-system files onto different
drives.
To accommodate more than one operating system.

110. Types Of Partitions
There are two types of partitions:
primary
 extended.
The primary partition is the location where the boot
information for the operating system is stored.
To boot from a hard disk drive, it must have a primary
partition.
Primary partitions are for storage of the boot sector,
which tells the computer where to find the operating
system. The name of the primary partition is C.

111. Extended Partitions
The extended partition is for a hard disk drive, or part
of a hard disk drive, that does not have an operating
system.
The extended partition is not associated with a
"physical" drive letter. Instead, the extended partition
is further divided into logical drives starting with D
and progressing until drive letter Z is created.

112. One 500-MB physical drive with one partition:
C (primary drive)
One physical drive and one logical drive
Figure 2
One 1-GB physical drive with two partitions:
C (400-MB primary drive)
D (600-MB extended drive)
One physical drive and two logical drives

113. How to make Partition

114. DOS
DOS stands for disk operating system.
All versions of DOS are actually the product of Microsoft
development.
The modern computer professional must be familiar
with MS-DOS because MS-DOS remains at the heart of
Windows
The three brands of DOS are:
MS-DOS, produced by Microsoft—the most popular
PC-DOS, produced by IBM
DR-DOS, produced by Novell

115. MS-DOS Commands
Check in the ppt (notes) files and practice on it

116. CD Media
CD-R
A CD-R (Compact Disc-Recordable) is a variation of
the Compact Disc digital audio disc invented by
Philips and Sony.
CD-RW
Compact Disc ReWritable (CD-RW) is a rewritable
optical disc format. Known as CD-Erasable (CD-E)
during its development, CD-RW was introduced in
1997,

117. Video
Basic Monitor Operation:
The Cathode-Ray Tube:
The cathode-ray tube (CRT) is the main component of a
traditional monitor
A cylinder that contains one or more electron guns.
Most color monitors have three guns in back— one for
each of the colors red, green, and blue.
This combination (usually referred to as RGB) allows the
visual production of all colors
The wide end of the CRT is the display screen, which has a
phosphor coating .

118. Screen Resolution and Pitch
The term resolution refers to the degree of detail offered
in the presentation of an image.
The method of measurement varies, based on the
medium—photographic lenses, films, and paper are
measured using lines per inch.
while computer-monitor manufacturers express
resolution in pixels per inch.
The greater the number of pixels per inch, the smaller
the detail that can be imaged, and, consequently, the
sharper the picture.

119. Screen Resolution and Pitch
Monitor resolution is usually expressed as "a" x "b"
where "a" is the number of horizontal pixels, and "b" is
the number of vertical pixels. For example, 640 x 480
means that the monitor resolution is 640 pixels
horizontally by 480 pixels vertically
Dot pitch: is a term used to define the diagonal
distance between the two closest dots of the same
color, usually expressed in millimeters.

120. Display Adapters
The monitor is only half of a
computer's display system; it must be
matched to a display adapter (also
commonly referred to as a graphics
adapter, video card, or video
controller).

121. Assignment no: 02
Video Memory
Fast Page DRAM
VRAM= (Video RAM). )
EDO DRAM= (Extended Data Out) )
WRAM= (Window Random Access Memory)
SGRAM= (Synchronous Graphics RAM). )
MDRAM= (Multibank DRAM)

122. Information Transfer Protocols
Communication relies (depend) on protocols. In
order to ensure clear and clean communication
without any errors, the device on each end must
follow a very strict set of rules
 If either device violates (not working) any of the
rules, the communication will fail. These rules are
called File Transfer Protocols (FTPs).

123. Telephone-Line Basics For
Modems
Modem connections to the telephone service are made
using two wires (ring and tip) that are used in a standard
telephone jack.
 The wires are named for the plug wires used in the original
telephone lines by which telephone operators would
manually connect two telephones at the phone company
switchboard.
 There are two versions of the telephone jack:
Half-duplex: The RJ-11 has only two wires, which make up one
line. Therefore, only one signal can be sent or received at a
time.

124. Printer Basics
Printer resolution:
 Resolution is usually measured in dots per inch (dpi).
 This indicates the number of vertical and horizontal
dots that can be printed; the higher the resolution,
the better the print quality

125. Impact Printers
Laser Printers
Ink-Jet Print

126. SURPRIZE QUIZ TEST
Q1: Explain virtual memory and cache memory ?
Q2: Define sound card and video card ?
Q3: What is the different b/w Parallel and series ports?
Q4: Define port and why we use ports in motherboard?
Q5: Define CPU packages with Pentiums ?
Q6: Define Male and Female connectors ?
Q7: Define INPUT devices with examples?