UNIT 1: Information Systems
Recap
What did we learn?
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What is an Information System?
What is Information Technology?
Information Processing cycle
Data vs Information
Qualities of Information
Computer vs Human capabilities
Defining IT competency
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Impact of IT on society and business
Categories of Computer Systems
Popular jobs in the IT field
Types of information systems
Match
A. Server computer:
B. Stylus:
C. Supercomputer:
1) processor-bound
applications
2) takes over when
computer fails
3) works with client
computers
4) electronic pen
True/False
The four size categories of
conventional personal computers are
– miniature,
– portable,
– notebook, and
– business
True/False
Supercomputers outperform humans when
it comes to pattern recognition.
True/False
The power of a PC is directly proportional to
its physical size.
Discuss
• Are the terms ‘Internet’ and ‘internet’ the
same? Discuss.
UNIT 2
Inside the Computer –
Hardware components &
functions
Computers
Inside the Computer
Objectives
Understand how data is stored and represented in a computer.
Describe the functions and relationships
between internal computer hardware components:
Cases, Power Supply, Motherboard, CPU, Cooling System, Memory,
Adapter card, Storage devices and Internal cables
Discuss several approaches to processor design.
Information Processing Cycle
Hardware Components
Computers
Inside the Computer
Digital: The Language of Computers
Analog – continuous waveforms;
frequency & amplitude variations, sound
Digital – data is described using only
two states: on and off
Computers
Inside the Computer
Digital: The Language of Computers
Digitize – to convert data, analog
signals, and images into 1’s and 0’s
used by computers
Computers
Inside the Computer
Digital: The Language of Computers
Binary – two-digit numbering system
1 represents on
0 represents off
Each 1 or 0 is called a bit
Bit – short for binary digit
Computers
Inside the Computer
Digital: The Language of Computers
Encoding systems :
ASCII – American Standard Code for
Information Interchange
ANSI – American National Standards
Institute
UNICODE – capable of handling most
printed languages
Computers
Inside the Computer
Digital: The Language of Computers
Byte – collection of bits that
represent a character
ASCII – 7 bits/byte
ANSI – 8 bits/byte
UNICODE – 16 bits/byte
ASCII
» American Standard Code for Information
Interchange (ASCII)
» ASCII code can represent up to 128
characters
» PC byte is 8 bits; there are 256 possible
bit configurations
Computers
Inside the Computer
Digital: The Language of Computers
Binary (base 2) – confusing for
humans; only uses 1’s and 0’s
Hexadecimal (base 16)
used to represent numbers using fewer digits
A=10, B=11, C=12, D=13, E=14, F=15
A shorthand for expressing Binary Numbers
» Base 16: used as shorthand to display contents
of RAM and disk storage
» 0-9 represents lower order digits and letters A to
F are used for the six higher order digits
» It only takes two hexadecimal digits to represent
an eight-bit byte.
Binary vs. Decimal vs.
Hexadecimal
Computer Form Factor
A computer’s form factor describes the computer’s
physical shape, layout and size of the major
components.
Computer Form factors:
Physical dimensions of major
components
Pictorial comparison of some common
computer form factors.
• The standardized size and layout of
motherboard have changed much more
slowly, and are controlled by their own
standards.
• The list of components a motherboard
must include changes far more slowly
than the components themselves.
• slower process - form factors evolve
regularly in response to changing
demands.
• The original PC standard (AT) was
superseded in 1995 by the current
industry standard ATX
• latest update to the ATX standard released
in 2007 - still dictates the size and design
of the motherboard , modern PCs.
• Differences between form factors are most
apparent in terms of
– intended market sector
– involve variations in size, design
compromises and typical features
• A desktop computer may require more
sockets for maximal flexibility and many
optional connectors and other features onboard
• whereas a computer to be used in a
multimedia system may need to be
optimized for heat and size, with additional
plug-in cards being less common.
• The smallest motherboards may sacrifice
CPU flexibility in favor of a fixed
manufacturer's choice.
Computer
Case/chassis/tower/cabinet/housing
• Framework – support internal parts
• Enclosure – protection from external
environment (dust)
• Protection of inner environment – airflow
and cooling
• Static electricity protection
– Grounded off parts
All-in-one computer systems
• All-in-ones have a single box that is the
display and computer versus the desktop
that is comprised of the computer case
plus a separate monitor. The
all-in-one PC still has an advantage over
these systems in the number of required
cables. Since the monitor is integrated into
the system, there isn't a need for a
monitor cable or separate display power
cord. This reduces the clutter on,
underneath or behind a desk.
Power Supply
• Converts AC to DC power(lower voltage)
• Has keyed connectors
• Supports all power needs of components
• SATA and Molex connectors
Computers
Inside the Computer
The PC System Unit
Motherboard – printed circuit board
Chipset – group of integrated circuits
(IC) that control communication between
system hardware, CPU and main board
Chipset – determines amount of memory
Motherboard Form Factors
• IBM’s AT
– Cumbersome – up to 1 foot wide
Computers
Inside the Computer
The PC System Unit
Connected to the Motherboard:
Processor
Chipset
Memory chips
Expansion boards
Computers
Inside the Computer
The PC System Unit
Motherboard
System bus(electrical pathways) –
permits communication between
components
Device controllers – control peripheral
devices
The PC System Unit - Mainboard
15 important items on a motherboard:
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CPU socket
• PCI slots
• The AGP
• The ISA slots
• The parallel port
• The serial port
• The PS2 port
• USB port
• IDE connectors
• • The chipset
• • The power
connector
• • The memory slots
• • The floppy drive
connector (FLOPPY)
• • CMOS battery
• • BIOS
• Before buying a motherboard, you should
always learn about its characteristics such
as the type of connectors it has.
Computers
Inside the Computer
• The Processor: Computer Brain on a Chip
Pentium 4
Celeron
XeonTM
ItaniumTM
Computers
Inside the Computer
The PC System Unit
Central Processing Unit
Control unit
Arithmetic and logic unit
Computers
Inside the Computer
Central Processing Unit
Control unit - the command centre of
the processor.
Reads and interprets instructions
Directs the operation of internal
processor components
Controls the flow of programs and
data in and out of RAM
Computers
Inside the Computer
Central Processing Unit
Decoder – interprets instructions that
have been retrieved from RAM
Registers – high-speed working
storage areas
instruction register – contains instruction
to be executed
program register – contains location of
next instruction to be executed
Computers
Inside the Computer
Central Processing Unit
Arithmetic and Logic Unit
Performs computations (+, -, *, /)
Performs logical operations (comparisons)
Accumulator – register where answers are
stored
During the execution of a program, what
happens:
•program instructions are moved from RAM to the
control unit
•decoder interprets the instructions
•Control unit directs other processor components to
carry out necessary instructions
Computers
Inside the Computer
The Instruction Set and the
Instruction Cycle
Machine language – what a computer
actually understands
All instructions to a computer must be
converted to binary
Instruction set – sequence of stored
instructions
Computers
Inside the Computer
The Instruction Set and the
Instruction Cycle
Instruction Cycle
Instruction time (I-time) – instruction is
retrieved from memory and decoded
Execution time (E-time) – instruction is
executed and result is placed in memory
The Instruction Set and the
Instruction Cycle
Computers
Inside the Computer
The Instruction Set and the
Instruction Cycle
Pipelining – processor begins
working
on another instruction before the
current instruction is completed
Pipelining
t – Time
t1 t2 t3 t4
Instruction 1: F D E
Instruction 2:
F D
Instruction 3:
F
t5 t6
S
E S
D E
S
The Instruction Set and the Instruction Cycle
1. CISC (complex instruction set computer)
•. understands many different instructions
•. a large amount of different & complex
instructions.
•. Fewer steps per operation
•. In common CISC chips are relatively slow
(compared to RISC chips) per instruction, but
use little (less than RISC) instructions.
The Instruction Set and the
Instruction Cycle
CISC (complex instruction set
computer)
Task: Find the product of X and Y
In a CISC processor:
MULT X,Y
The Instruction Set and the Instruction Cycle
– two main CPU architectures
2. RISC (reduced instruction set computer)
• understands a smaller list of instructions
• Fewer, simpler and faster instructions would be
better, than the large, complex and slower CISC
instructions.
• However, more instructions are needed to
accomplish a task with RISC.
• Executed very rapidly
The Instruction Set and the
Instruction Cycle
. RISC (reduced instruction set
computer)
Task: Find the product of X and Y
In a RISC processor:
Load Y from memory in register1
Load X from memory in register2
Prod register1, register2
Store answer back in memory
CPU
• Overclocking:
make processor work faster than original
speed specification
• Throttling:
processor runs at less than rated speed to
produce less heat/conserve power
Computers
Inside the Computer
Processor Design
Parallel processing – multiple
processors in one computer system
Process multiple instructions concurrently
Single-core
Dual-core
Quad-core – 4 cores inside 1 CPU;
Simultaneous processing for enhanced computer
apps.
Computers
Inside the Computer
Describing the Processor and Its
Performance
Word or Bus Width – number of bits
handled as a unit
Computers
Inside the Computer
Core Speed: GHz, MIPS, and FLOPS
Gigahertz (GHz) – billions of clock
cycles per second
Megahertz (MHz) – millions of clock
cycles per second
Computers
Inside the Computer
Core Speed: GHz, MIPS, and FLOPS
MIPS – millions of instructions per
second
FLOPS – floating point operations per
second; used to measure speed of
supercomputers
Computers
Inside the Computer
Bus Speed
Most processors operate at GHz
Most buses operate at MHz
Major block to efficiency in a PC
CMOS battery
• a small battery (flat) that does not
consume much electricity is used to keep
track of the initialization settings of the
computer. It is also used to operate the
PC’s internal clock so if you see that the
time is that the malfunctioning battery is
not good is it to be changed.
The BIOS
• small program stored in a ROM for
performing exchange of information
between the operating system (usually
Windows) and the motherboard.
• ** How to clear BIOS exercise
Cooling System
• Case fans
• Heat sink on CPU
• Remove heat
• Promote cooling in
case
• Video Cards
– GeForce
Computers
Inside the Computer
High-Speed Memories
RAM
ROM (read-only memory) –
non-volatile, contains
instructions to the computer that the
user cannot change ; holds firmware
Eg?
PROM (programmable ROM) – user
can store read-only programs and data
ROM
• Good example of
ROM is EEPROM
used for the computer
BIOS
• Electrically Erasable
Programmable ReadOnly Memory,
EEPROM is a PROM
that can be erased
and reprogrammed
using an electrical
charg
Computers
Inside the Computer
Flash Memory
Nonvolatile memory – does not lose data
in a power outage
Easily upgraded
BIOS (Basic Input Output System) –
stored in flash memory
Computers
Inside the Computer
RAM: Digital Warehouse
High-speed holding area for data and
programs
Volatile memory – data is lost if
electrical current is not maintained
Address – specific location in RAM
RAM
• Clip-in modules, called memory sticks (not
to be confused with USB Flash drives
which sometimes go by that name).
Computers
Inside the Computer
• Cache
Throughput – rate at
which the
computer works
Cache Memory –
faster than RAM
SRAM
L1, L2, L3 – integrated on
CPU
Gives CPU faster access
to data
Computers
Inside the Computer
Memory Capacity
MB (megabyte) – approximately 1
million bytes
GB (gigabyte) – approximately 1
billion bytes
TB (terabyte) – approximately 1
trillion bytes
Computers
Inside the Computer
Memory Capacity
KB (kilobytes) – approximately 1000
bytes
Kb (kilobit)
Mb (megabit)
Memory sticks or modules changed format over the years as
capacity has increased. Main types, in increasing complexity,
• SIMM - Single Inline Memory Module - an
obsolete type of memory stick with power
and data contacts on one side of the
board. 30 pins.
• DIMM - Dual Inline Memory Module - a
memory stick with power and data
contacts on both sides of the board.
RAM: Digital Warehouse
DDR SDRAM – synchronous
dynamic RAM
SIMMs – single in-line memory
modules (30 and 72 pins)
DIMMs – dual in-line memory
modules (168, 184 and 240 pins)
DDR vs DDR2
• DDR - Double Data Rate memory – 184 pin
modules
– a type of DRAM based on SDRAM technology
– operates at twice the bus clock rate.
– It uses. Released in 2000.
– mainstream memory technology to the end of 2005.
• DDR2 - Double Data Rate2 memory – 240 pins
– a type of DRAM based on DDR technology
– operates at twice the clock rate.
– Released in 2004.
– Not compatible with DDR motherboards.
DDR2 vs DDR3
Type of RAM
PC Rating
RAM Speed
in MHz
Peak Throughput
in MB/sec
SDRAM
PC100
100
800
SDRAM
PC133
133
1100
RIMM
PC800
400
1600
RIMM
PC1066
533
2100
DDR
PC1600
200
1600
DDR
PC2100
266
2100
DDR
PC2700
366
2700
DDR
PC3200
400
3200
Dual Channel RIMM
PC800
400
3200
Dual Channel RIMM
PC1066
533
4200
Dual Channel DDR2
PC2-3200
400
6400
Dual Channel DDR2
PC2-4200
533
8400
Dual Channel DDR2
PC2-5300
667
10600
Dual Channel DDR2
PC2-6400
800
12800
Identify RAM
What types of RAM does a laptop use?
What types of RAM does a laptop use?
• Either SODIMM or MicroSODIMM.
• Small outline dual in-line memory module - a
miniaturized version of the DIMM modules used in
most desktop PCs.
• A broad question with a broad answer - modern
laptops usually use 200 pin SODIMMs
They could be DDR or DDR2, which are not
interchangeable.
• You would have to check the specs of your specific
laptop to find out.
The Processor and Memory
A computer’s
speed
and
capacity
is
determined by
the type of
processor and
the amount of
RAM on the
motherboard
Computers
Inside the Computer
Buses and Ports
PCI (peripheral component
interconnect) local bus – allows for
circuit boards to connect to the
common system bus
Computers
Inside the Computer
Buses and Ports
Expansion slots – where expansion
boards are installed
Expansion boards or expansion/adapter cards
–
provide additional capabilities to the
computer
Computers
Inside the Computer
Buses and Ports
AGP (accelerated graphics port) bus–
speeds up high-resolution 3-D
graphics
Computers
Inside the Computer
Buses and Ports
USB (universal serial bus) – used to
connect peripheral devices to the PC
USB hub – connects to the USB port
and provides additional places to plug
USB devices
Computers
Inside the Computer
Buses and Ports
Hot plug – USB devices can be
attached or removed while the PC is
running
USB 1.0 – 12Mbps
USB 2.0 – about 40 times faster than
original USB = 480 Mbps
USB 3.0 – 5 Gbps
Computers
Inside the Computer
Buses and Ports
1394 bus – similar to
USB in speed
FireWire – Apple
terminology
Supports hot plugging
Computers
Inside the Computer
Buses and Ports
SCSI (small computer system
interface) or “scuzzy” bus – early
alternative to expansion slots in PCs
Computers
Inside the Computer
Legacy and Other PC Ports
Serial port – data flows one bit at a time
Parallel port – data flows several bits at
a time
IrDA port or infrared port – data sent by
light waves
Computers
Inside the Computer
PC Growth: Adding Capabilities
Expansion Boards – placed in
expansion slots
Graphics adapter
Sound
Data/voice/fax modem
Network interface card (NIC)
SCSI interface card
Video capture card
Wireless NIC
Computers
Inside the Computer
PC Cards: PCMCIA Technology
PCMCIA card or PC card
Usually used on notebook computers
Expand RAM
NIC
Hard-disk cards
GPS (global positioning system)
Internal Cables
• SATA power connectors
– SATA drives
Computers
Inside the Computer
Build Your Own PC
Advantages
Cheaper (for high-end systems)
Meets your requirements
Disadvantages
No warranty on system
No help desk
Computers
Unit 2 – Inside the Computer
Lesson Summary
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Understand how data is stored and
represented in a computer
Describe the functions and relationships
between main internal computer
hardware components
Distinguish processors by word size,
speed, and memory capability
Identify new processor design
approaches