The document provides information about the components inside a computer system unit, including the processor, memory, ports, and expansion slots. It describes the motherboard as the main circuit board that contains these components and how memory is used to store instructions and data. The document explains how computers represent data using binary digits and the basics of how programs load into memory to be executed by the processor. It provides guidelines for selecting RAM capacity based on intended application usage.
2. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Chapter 4 Objectives styles
Differentiate among various Differentiate among the various
of system units types of memory
Identify chips, adapter cards, and other Describe the types of expansion slots and
components of a motherboard adapter cards
Explain the differences among a serial port, a
Describe the components of a processor and parallel port, a USB port, a FireWire port, and other
how they complete a machine cycle ports
Identify characteristics of various personal Describe how buses contribute to a
computer processors on the market today computer’s processing speed
Define a bit and describe how a series of bits Identify components in mobile computers
represents data and mobile devices
Explain how programs transfer in
Understand how to clean a system unit
and out of memory
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The System Unit
What is the system unit?
Case that contains electronic
components of the computer used
to process data
Sometimes called
the chassis
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4. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
The are common components inside the system unit?
What
System Unit
drive bays
Processor power supply
Memory
Adapter cards
Sound card processor
Video card
Ports
Drive bays ports memory
Power supply
sound card
video card
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BTECH1101 | Fundamental of Computer Systems
The System Unit
What is the motherboard?
Main circuit board in
system unit
Contains adapter cards,
processor chips, and
memory chips
Also called system board
Click to view Web Link,
click Chapter 4, Click Web Link
from left navigation,
then click Motherboards below
Chapter
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6. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
The System Unit
What is a chip?
Small piece of semi-conducting material on which integrated circuits are etched
Integrated circuits contain many microscopic pathways capable of carrying
electrical current
Chips are packaged so they can be attached to a circuit board
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7. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Processor
What is the central processing unit (CPU)?
Interprets and carries out basic
instructions that operate a Processor
computer Control
Control Arithmetic
Arithmetic
Unit
Unit Logic Unit (ALU)
Logic Unit (ALU)
Control unit directs and
coordinates operations in Instructions
Data
computer
Informatio
n
Arithmetic logic unit
(ALU) performs Input Output
arithmetic, comparison, Devices
Data Memory Information
Devices
and logical operations
Instructions
Also called the processor Data
Informatio
n
Storage
Devices
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8. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Processor
What is a machine cycle?
Four operations of the CPU comprise a machine cycle
Step 1. Fetch
Obtain program
instruction or data item
from memory
Memory
Step 2.
Step 4. Store Decode
Write result to memory Translate
instruction into
Processor commands
ALU Control Unit
Step 3.
Execute
Carry out command
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BTECH1101 | Fundamental of Computer Systems
Processor
What is pipelining?
CPU begins fetching second instruction before completing machine cycle for first
instruction
Results in faster processing
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10. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Processor
What is a register?
Temporary high-speed storage area that holds
data and instructions
Stores location
from where instruction
was fetched
Stores Stores data
instruction while it is while ALU
being decoded computes it
Stores results
of calculation
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11. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Processor
What is the system clock?
Controls timing of all computer operations
Generates regular electronic pulses, or ticks, that set operating pace of components of
system unit
Pace of system
clock is clock speed
Processor speed can
Each tick Most clock speeds are
also be measured in
is a in the gigahertz (GHz)
millions of instructions
clock cycle range (1 GHz = one
per second (MIPS)
billion ticks of system
clock per second)
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BTECH1101 | Fundamental of Computer Systems
Processor should you select?
Which processor
The faster the processor, the more expensive the computer
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Processor
What are the guidelines for selecting a processor?
Click to view Web Link,
click Chapter 4, Click Web Link
from left navigation,
then click Clock Dual-Core
Processors below Chapter
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BTECH1101 | Fundamental of Computer Systems
Processor
What are heat sinks, heat pipes, and liquid cooling?
Heat sink—component
with fins that cools
processor
Heat pipee—smaller
device for notebook
computers
Liquid cooling—uses a continuous flow
of fluids to transfer heat away
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15. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Processor
What is parallel processing? Control Processor
Using multiple processors
simultaneously to
execute a program faster Processor 1 Processor 2 Processor 3 Processor 4
Memory Memory Memory Memory
Requires special software
to divide problem and
bring results together
Results combined
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16. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Data Representation
How do computers represent data?
Most computers are digital
Recognize only two discrete
states: on or off
Use a binary system to recognize
two states
Use Number system with two
unique digits: 0 and 1, called bits
(short for binary digits)
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17. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Data Representation
What is a byte?
Eight bits grouped together as a unit
Provides enough different combinations of 0s and 1s to represent 256 individual
characters
Numbers
Uppercase
and lowercase
letters
Punctuation
marks
Other
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18. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Data Representation
What are three popular coding systems to represent data?
ASCII—American Standard Code for Information Interchange
EBCDIC—Extended Binary Coded Decimal Interchange Code
Unicode—coding scheme capable of representing all
world’s languages
ASCII Symbol EBCDIC
00110000 0 11110000
00110001 1 11110001
00110010 2 11110010
00110011 3 11110011
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19. Faculty of Information and Communication Technology
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Data Representation
How is a letter converted to binary form and back?
Step 1.
The user Step 2.
presses the An electronic signal for
capital letter T the capital letter T is sent
(shift+T key) on to the system unit.
the keyboard.
T
Step 4. Step 3.
After processing, the binary The signal for the capital letter
code for the capital letter T is T is converted to its ASCII
converted to an image, and binary code (01010100) and
displayed on the output is stored in memory for
device. processing.
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20. Faculty of Information and Communication Technology
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Memory
What is memory?
Electronic components that store
instructions, data, and results
Consists of one or
more chips on
motherboard or
other circuit board
Each byte stored
in unique location
called an address,
similar to seats in a concert hall
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Memory
How is memory measured?
By number of bytes available for storage
Term Abbreviation Approximate Size
Kilobyte KB or K 1 thousand bytes
Megabyte MB 1 million bytes
Gigabyte GB 1 billion bytes
Terabyte TB 1 trillion bytes
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22. Faculty of Information and Communication Technology
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Memory
What is random access memory (RAM)?
Memory chips that can be
read from and written
to by processor
Most RAM is
Also called
volatile, it is lost
main memory
when computer’s
or primary
power is
storage
turned off
The more RAM a
computer has, the
Click to view Web Link, faster it responds
click Chapter 4, Click Web Link
from left navigation,
then click RAM below Chapter
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23. Faculty of Information and Communication Technology
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Memory
How do program instructions transfer in and out of RAM?
RAM Step 1. When you start the computer, certain
operating system files are loaded into RAM from
Operating system Operating system the hard disk. The operating system displays the
user interface on the screen.
instructions interface
Step 2. When you start a Web browser, the
program’s instructions are loaded into RAM from
Web browser Web browser the hard disk. The Web browser window is
instructions window displayed on the screen.
Step 3. When you start a word processing
program, the program’s instructions are loaded
into RAM from the hard disk. The word
Word processing Word processing processing program, along with the Web Browser
program instructions program window and certain operating system instructions are in
RAM. The word processing program window is
RAM
displayed on the screen.
Step 4. When you quit a program, such as the
Web browser, its program instructions are
removed from RAM. The Web browser is no
longer displayed on the screen.
Web browser program Web browser window is no
instructions are removed longer displayed on desktop
from RAM
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24. Faculty of Information and Communication Technology
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Memory
What are two basic types of RAM chips?
Do not have to
Most Static be re-energized
common
type RAM as often as
DRAM
(SRAM)
Dynamic
Must be RAM Faster and
more reliable
re-energized
constantly
(DRAM) than DRAM
chips
Newer Type: Magnetoresistive RAM (MRAM)
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25. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
dual inline memory module
Memory
Where does memory reside?
Resides on small circuit board called
memory module
Memory slots on motherboard hold memory
modules
memory slot
memory chip
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26. Faculty of Information and Communication Technology
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Memory
How much RAM does an application require?
Depends on the types of software
you plan to use
For optimal
performance, you
need more than
minimum specifications
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27. Faculty of Information and Communication Technology
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Memory
How much RAM do you need?
Depends on type of applications you intend to run
on your computer
RAM 256 MB to 1 GB 512 MB to 2 GB 2 GB and up
Use • Home and business • Users requiring more advanced • Power users creating
users managing multimedia capabilities professional Web sites
personal finance • Running number-intensive • Running sophisticated
• Using standard accounting, financial, or CAD, 3D design, or
application software spreadsheet programs other graphics-intensive
such as word processing • Using voice recognition software
• Using educational • Working with videos, music, and
or entertainment digital imaging
CD-ROMs • Creating Web sites
• Communicating with • Participating in video conferences
others on the Web • Playing Internet games
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28. Faculty of Information and Communication Technology
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Memory
What is cache?
Helps speed computer processes by storing frequently used instructions and data
Also called memory cache
L1 cache built into processor
L2 cache slower but has larger capacity
L2 advanced transfer cache is faster, built
directly on processor chip
L3 cache is separate from processor chip on
motherboard (L3 is only
on computers that use L2 advanced transfer
Click to view Web Link,
click Chapter 4, Click cache)
Web Link from left
navigation, then click
Cache below Chapter
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29. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Memory
What is read-only memory (ROM)?
Memory chips that store Nonvolatile memory, it is not lost
permanent data and instructions when computer’s power is turned off
Three types:
EEPROM
Firmware— (electrically
Manufactured with erasable programmable
permanently written read-only memory)—
data, instructions, PROM Type of PROM
or information (programmable containing microcode
read-only programmer
memory)— can erase
Blank ROM
chip onto which
a programmer
can write permanently
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30. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Memory
What is flash memory?
Nonvolatile memory that can be erased electronically and rewritten
Used with PDAs, smart phones, printers, digital cameras, automotive devices, audio
players, digital voice recorders, and pagers
Step 3.
Step 1. Plug the headphones into the
Purchase and download MP3 music MP3 player, push a button on the
tracks from a Web site. With one end of flash memory
chips MP3 player, and listen to the
a special cable connected to the system music through the headphones.
unit, connect the other end into the
MP3 player.
USB port
Click to view Web Link, Step 2.
click Chapter 4, Click Web Link Instruct the computer to copy the MP3 music
from left navigation, MP3 Player
track to the flash memory chip in the MP3
then click Flash Memory player.
below Chapter 4
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Memory
What is CMOS?
Used in some
Complementary RAM chips, flash
metal-oxide memory chips,
semiconductor and other types of
memory memory chips
Uses battery Stores date,
power to retain time, and
information when computer’s
other power is startup
turned off information
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32. Faculty of Information and Communication Technology
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Memory
What is access time?
Amount of time it takes processor
to read data from memory
Measured in nanoseconds (ns),
one billionth of a second
It takes 1/10 of a second to blink
your eye; a computer can perform
up to 10 million operations in same amount of time
Term Speed
Millisecond One-thousandth of a second
Microsecond One-millionth of a second
Nanosecond One-billionth of a second
Picosecond One-trillionth of a second
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33. Faculty of Information and Communication Technology
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Expansion Slots and Adapter Cards
What is an adapter card?
Enhances system unit or provides connections to external devices called
peripherals
Also called an expansion card
Click to view Web Link,
click Chapter 4, Click Web Link
from left navigation,
then click Sound Cards
below Chapter 4
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34. Faculty of Information and Communication Technology
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Expansion Slots and Adapter Cards
What is an expansion slot?
An opening, or socket,
on the motherboard
that can hold an
adapter card
With Plug and Play,
the computer
automatically
configures cards
and other devices
as you install them
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35. Faculty of Information and Communication Technology
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Expansion Slots and Adapter Cards
What are PC cards, and flash memory cards?
A PC card adds memory, storage, sound,
fax/modem, communications, and other capabilities
to notebook computers
A flash memory card allows users to transfer data
from mobile devices to desktop computers
USB Flash drive
Click to view Web Link,
click Chapter 4, Click Web Link
from left navigation,
then click Removable Flash
Memory Devices
below Chapter 4
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36. Faculty of Information and Communication Technology
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Ports and Connectors
What are ports and connectors?
Port connects external devices to system unit
Connector joins cable to peripheral
Available in one of two genders: male and female
Click to view Web Link,
click Chapter 4, Click Web Link
from left navigation,
then click Ports and Connectors
below Chapter 4
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37. Faculty of Information and Communication Technology
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Ports and Connectors
What are different types of connectors?
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38. Faculty of Information and Communication Technology
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Ports and Connectors
What is a serial port?
Transmits one bit of data at a time
Connects slow-speed devices, such as mouse,
keyboard, modem
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39. Faculty of Information and Communication Technology
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Ports and Connectors
What is a parallel port?
Connects devices that can transfer more than
one bit at a time, such as a printer
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40. Faculty of Information and Communication Technology
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Ports and Connectors
What are USB ports?
USB (universal serial bus) port can connect
up to 127 different peripherals together
with a single connector type
PCs typically have
six to eight USB ports Single USB port can Third USB
on front or back of be used to attach device connects
multiple peripherals to second USB
the system unit device, and so on
in a daisy chain
USB 2.0 First USB Second USB
device connects device connects
to USB port to first USB
on computer device
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41. Faculty of Information and Communication Technology
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Ports and Connectors
What are FireWire ports?
Connects multiple types of devices that require faster data transmission
speeds
Allows you to connect up to 63 devices together
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42. Faculty of Information and Communication Technology
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Ports and Connectors
What are special-purpose ports?
Allow users to attach specialized peripherals or transmit data to wireless devices
MIDI (Musical Instrument
Digital Interface) port
SCSI (small computer
system interface) port
IrDA (Infrared Data
Association) port
Bluetooth port
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43. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Buses
What is a bus?
Channel that allows devices inside computer
to communicate with each other
System bus connects processor and
RAM
Bus width determines number of bits
transmitted at one time
Word size is the number of
bits processor can interpret
Click to view Web Link, and execute at a given time
click Chapter 4, Click Web Link
from left navigation,
then click Buses below
Chapter 4
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44. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Buses
What is an expansion bus?
Allows processor to communicate with peripherals
PC Card FireWire USB AGP PCI
Bus Bus Bus Bus Bus
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45. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Bays
What is a bay?
Open area inside system unit
used to install additional
equipment
Drive bays typically hold disk
drives
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46. Faculty of Information and Communication Technology
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Power Supply
What is a power supply?
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47. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Mobile Computers and Devices
What is a mobile computer?
Notebook, weighing between 2.5 and 9
pounds, or mobile device such as a
PDA
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48. Faculty of Information and Communication Technology
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Mobile Computers and Devices
What ports are on a notebook computer?
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49. Faculty of Information and Communication Technology
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Mobile Computers and Devices
What ports and slots are on a tablet PC?
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50. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Putting It All Together
What are suggested processor, clock speed, and RAM requirements based on the needs
of various types of users?
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51. Faculty of Information and Communication Technology
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Keeping Your Computer Clean
Over time, the system unit collects dust – even in a clean environment
Preventative maintenance requires a few basic products:
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52. Faculty of Information and Communication Technology
BTECH1101 | Fundamental of Computer Systems
Summary of the Components of the System Unit
Components of the system unit
Comparison of various personal computer
processors on the market today
How memory stores data, instructions,
and information
How to clean a system unit
Sequence of operations that occur when a
computer executes an instruction
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53. Faculty of Information and Communication Technology
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End of Lecture
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