Transcript Hardware Terminology

Week 1 – How Computers Work
COMP1002 - Computer Concepts with Microsoft Windows
1
Computer Systems
What is a computer?
Data Processing Cycle
2
Data Processing Cycle
Input
(Data)
Processing (Data is manipulated)
Output
(Information)
Storage
(Permanent record)
Data becomes Information when it is manipulated and converted
to a format people can understand and use
Data Processing Cycle
3
Steps in more detail e.g. Using a Scanner
• Input
– Scan a picture or document on a scanner
– A stream of 0’s and 1’s (binary data) is sent via a cable to the computer
– This raw data is unusable by a human being
• Processing
– A software program installed with your scanner receives the stream of binary data
– Instructions in the program tell the computer how to convert the raw data into
something useful – information
• Output
– Depending on the instructions, various types of output/information can be generated
• picture on the screen
• editable text file
• fax
• Storage
– Data that has been processed into information can be stored as a file
Data Processing Cycle
4
How do computers represent data
• Computers represent and transmit many types of data
– Images
– Video
– Text
– Program code
• Representing this data must be
– Reliable
– Flexible
– Unambiguous
Data Processing Cycle
Bits and Bytes
5
Unambiguous and reliable
• ‘0 ‘or ‘1’ / Off or On / False or True / there or not there
• There is a mathematical system called binary that
allows us to represent any numerical value using only
the digits 0 and 1
Data Processing Cycle
Bits and Bytes
6
Flexible
• Computers can use numbers to represent other data:
– Characters – ASCII or Unicode values
• Each character has a numerical equivalent – A = 65 = 0100001
– Images – RGB values
• Each colour has a numerical value representing the amount of
red green and blue
– Audio – Sound Pressure Levels
• Each sample (taken thousands of times per second) represents
the fluctuation of pressure levels which generate sound
• All of these numbers are stored by the computer as binary
values
Data Processing Cycle
Bits and Bytes
7
Bits and Bytes
• 0 or 1 value is a bit (represented by lower case ‘b’)
– 80b = 80 bits
• 8 bits make a Byte (represented by upper case ‘B’)
– 10B = 10 bytes = 80 bits
• Bits and Bytes are how we measure:
• file size
• media capacity
• transmission speeds
Data Processing Cycle
Bits and Bytes
50KB
500GB
80Mbps
8
Quantifying Bits and Bytes
Data Processing Cycle
Bits and Bytes
9
Hardware vs Software
• Hardware
– Electric, electronic and electro-mechanical components
– Tangible, you can see and touch it
– Term includes Peripherals (components external to system unit)
• Software
– Intangible, we only see the effects of software
– Sets of instructions stored on disks and in memory that allow a
computer to perform useful tasks via
‘Arithmetic computations and Logical comparisons’
Data Processing Cycle
Bits and Bytes
Hardware
10
Motherboard
Data Processing Cycle
Bits and Bytes
Hardware
11
Motherboard
• Central element of a computer system’s processing
hardware is main circuitry board known as..
– Motherboard
– System board
– Main board
• Hosts buses, CPU, memory, clock, storage controllers,
expansion slots, physical and ‘virtual’ ports
Data Processing Cycle
Bits and Bytes
Hardware
12
Read Only Memory (ROM)
• Holds startup instructions, config data
– BIOS:
Basic Input Output System
• Tells PC to find operating system
and begin process of ‘booting’
during POST (Power On Self Test)
– CMOS:
• Stores the system configuration
• Non-volatile:
– Contents sustained by battery on
main board
Data Processing Cycle
Bits and Bytes
Hardware
13
Storage Hardware
• Magnetic, Optical and Solid State Storage
• Non-volatile (data remains after power off).
– This is where you permanently store your work and programs
Data Processing Cycle
Bits and Bytes
Hardware
14
ElectroMagnetic Storage
• Hard Drive, Floppy Disk, Tape
– Data stored as positive or negatively
charged magnetic particles
– Provide equivalent of ‘0’s and ‘1’s
Data Processing Cycle
Bits and Bytes
Hardware
15
Optical Storage
• CD, DVD
– Stores data as light and dark
spots on the disk medium
– Laser reflecting off pits and
lands provide equivalent of
‘0’s and ‘1’s
Data Processing Cycle
Bits and Bytes
Hardware
16
Solid State Storage
• Data stored in a chip’s circuits
– If circuits are open, value is ‘1’
– If they are closed, value is ‘0’
• Memory cards (digital
camera)/USB flash drive
• Newer hard drives (aka. SSD
drives)
Data Processing Cycle
Bits and Bytes
Hardware
17
Hybrid storage
• Single drive enclosure with both SSD and Magnetic
hard drive components.
• Two different approaches
1. Shows up as two different drives (i.e. C:\ and D:\)
and you put your Operating System and
applications on the SSD portion and data on the
magnetic portion
2. Shows up as a single drive and self-optimizes
putting the most frequently used files (application
or data) on the SSD portion
18
Random Access Memory (RAM)
19
Random Access Memory (RAM)
• RAM
– Consists of billions of capacitors which can hold a charge
– Acts as a temporary ‘working area’ for the processor
– Retrieving data, instructions directly from a hard drive to the
processor is slow. Faster to preload to RAM to speed up retrieval
– When you launch an program or file, instructions that make up that
program or file are copied from a storage device to RAM
– As processor needs new instructions or data they are taken from RAM
and copied to ‘cache’ memory on the processor
• NOTE: RAM is dynamic, volatile
– Contents sustained by electronic pulses while PC powered on
– All content LOST if PC loses power or is ‘rebooted’
Data Processing Cycle
Bits and Bytes
Hardware
20
Microprocessor
21
Microprocessor
• The brain of the computer is the processor.
– a.k.a. microprocessor, or Central Processing Unit (CPU)
• Performs the program instructions and manipulates
the data into information
• CPU contains two main parts:
– Control Unit (CU)
– Arithmetic/Logic Unit (ALU)
Data Processing Cycle
Bits and Bytes
Fetches instructions, data
Performs the instructions
Hardware
22
Cache Memory
• Memory inside processor
– Holds instructions, data to be processed
– Fast, expensive, temporary
• Processor predicts what data, instructions need to be
loaded next and pre-loads them into cache memory
• Usually 2-3 levels - level 1 is faster than level 2 which is
faster than level 3
• Differentiator between high end and budget processors
Data Processing Cycle
Bits and Bytes
Hardware
23
Processor Speeds
• Key factors in how a processor performs
– 64bit vs. 32bit – determines the amount of data that can be
processed at once and ability to access large banks of memory
– Mobile vs. Desktop – speed and energy efficiency
– HyperThreading – duplicates certain parts of the processor to
allow some parallel processing
– Multi-core – duplicates the entire processor to allow true
parallel processing
– Cache memory – determines how much data and how many
instructions are pre-loaded ready for processing
http://www.intel.com/content/www/us/en/processor-comparison/compare-intel-processors.html
Data Processing Cycle
Bits and Bytes
Hardware
24
Input and Output: Ports
• Provide pathways in and out of the system
• Serial, Parallel
– Almost obsolete, but still available, and in use
• USB
– Digital Camera, PDA, printers, mouse, keyboard
– 12 Mbps (USB1.1), 480 Mbps (USB2.0), 4.8Gbps (USB3.0)
• Thunderbolt
– Combines PCIexpress and DisplayPort technologies to allow
simple connections of external hard drives and extra displays
– 10+Gbps
Data Processing Cycle
Bits and Bytes
Hardware
25
Ports
26
Expansion Slots
27
Expansion
• Computer functionality can be increased by adding
expansion devices in slots on the motherboard
– PCI:
peripheral component interface (32 bit)
• Sound, network, modem sharing
• AGP: accelerated graphics port improved video output
– Video card only, now obsolete
– PCI-E: PCI-Express (64 bit)
• high speed large amounts of data movement
• good for video output
• can address very large amounts of memory
Data Processing Cycle
Bits and Bytes
Hardware
28