Intro ch 01_a
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Transcript of Intro ch 01_a
Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
McGraw-Hill Technology EducationMcGraw-Hill Technology Education Copyright © 2006 by The McGraw-Hill Companies, Inc. All
rights reserved.
Edited by: Edited by: Rahman Ali, Lecturer in Rahman Ali, Lecturer in Computer Science, QACC, Computer Science, QACC, University of PeshawarUniversity of Peshawar
Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
McGraw-Hill Technology Education
Chapter 1A
Introducing Computer Systems
Introducing Computer Systems
The Computer Definition“A computer is a device that accepts input, manipulates
it under a sequence of instructions (a program) and produces an output”.
“ It is a device that accept data (INPUT) , convert it into electronic pulses and signals, perform certain steps on the data under given instructions (PROCESSING) and generates desired results in human understandable form (OUTPUT)”.
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InputInput ProcessingProcessingInstructionsInstructions
OutputOutput
Data vs InformationData : “Any Combination of facts and figures in
their raw or unprocessed form .“ e.g. individual facts like first name, price,
quantity ordered ,Names of cities, digits, alphabets etc.
Information: “ It is a meaningful collection of data” OR “ Information is the raw data that has been manipulated
and organized in the form of results/outputs, up on which people can take necessary decisions”
e.g. A sorted list of names , a telephone bill , a record of student’s marks.
Data is processed by the computers to produce relevant information.
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Uses of computers
• Computers for individual uses
• Computers for organizations uses
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Computers For Individual Use
• Mostly computers are used by individual users. This means that they cannot be used by more than one users at a time.
• Some computers are shared (used) by multiple users at a time.
• NOTE:– These computers are called personal
computers– Also called microcomputers
Types of personal computers (PC)
• Desktop
• Workstation
• Notebook
• Laptop
• Tablet
• Handheld: Palmtop or pocket PC, PDA
• Smart phone: cell phone+PDA
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Desktop computer
• A desktop computer is a personal computer (PC) in a form intended for regular use at a single location.
• Early desktop computers are designed to lay flat on the desk, while modern towers stand upright.
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Workstations
• It is a type of computer used for: – engineering applications (CAD/CAM), – desktop publishing, – software development, and – other types of applications that require a
moderate amount of computing power and relatively high quality graphics capabilities.
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Workstations
• Most workstations are single-user computers. • The term workstation has also been used to
refer to a mainframe computer terminal.• In networking, workstation refers to any
computer connected to a local-area network. It could be a workstation or a personal computer.
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Desktop vs workstation
• Workstations offered higher performance than desktop computers, especially with respect to CPU and graphics, memory capacity and multitasking capability.
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Notebook computers• Notebook computers are:
– Small portable computers– Weighs between 3 and 8 pounds– About 8 ½ by 11 inches– Typically as powerful as a desktop– Also called laptop– Can include a docking station: to connect large
monitor, keyboard and mouse
Laptop • A small, portable computer -- small enough that it can
sit on your lap. Nowadays, laptop computers are more frequently called notebook computers.
• Similar in operation to desktops• Powerful than notebook• Laptop computers are miniaturized and optimized for
mobile use. • They are enabled with an inbuilt keyboard, touch pad
acting as a mouse and a
liquid crystal display.
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Tablet computers
• Tablet computers– Newest development
in portable computers
– Run specialized versions of office products
– They use the touch screen technology.
– Tablets come with an onscreen keyboard or use a stylus or a digital pen.
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• Handheld computers– Very small computers– Also called Palmtop or pocket PC– Personal Digital Assistants (PDA)– Note taking or contact management: phone
directory, agenda of the meetings– Data can synchronize with a desktop– Can connect to a wireless network for
Internet
Handheld computers
Handheld computers
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Smart phones
• Smart phones– Hybrid of cell phone and PDA– Web surfing, e-mail access
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Computers For Organizations
• Computers are not only used by individuals
• Some computers are used by more than one users at a time i.e. enterprises, schools, companies
• Thousands of users are attached
Types of Computers For Organizations
• Network servers
• Mainframe
• Minicomputers
• Microcomputers
• Supercomputers
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Network servers
• Network servers– Centralized computer– All other computers connect– Provides access to network resources– Multiple servers are called server farms or
cluster– Often simply a powerful desktop– Desktop, laptops, tablets and workstations
are attached either wired network or wireless
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Network servers
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Mainframes• Used in large organizations• Handle thousands of users• Users access through a
terminal:– Dump terminal:
• no processing no storage
– Intelligent terminal: • processing is there but no storage
– Standard PC:• Having both
• Mostly specialized for its tasks e.g. mainframe in State’s department of motor vehicle for storing drivers, drivers license etc. and nothing else.
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Minicomputers
• Minicomputers– First released in 1960’s– Called midrange computers– Power between mainframe and desktop– a minicomputer is a multiprocessing system
capable of supporting from up to 200 users simultaneously.
– Used in smaller organizations– Users access through a terminal
Minicomputers
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Supercomputers
• Supercomputers– The most powerful
computers made– Handle large and
complex calculations– Process trillions of
operations per second
– Found in research organizations, weather forecasting etc.
Supercomputers
• Other applications– Quantum physics, – mechanics, – molecular theory– Modeling complex processes like nuclear fission and fusion
reactions – Mapping human genome
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Supercomputers
1A-27 IBM Blue Gene P supercomputerIBM Blue Gene P supercomputer
Supercomputers
Titan: Fastest computer of the world1A-28
Supercomputers
• Titan, is the world’s fastest computer• Developed by US department of energy• Have a speed of 20000 trillion calculations
per second, equal to 20 petaflops/second• Before this, Tianhe-1A, was made by
China, in November 2010, which was the fastest supercomputer. The speed was 2.5 petaflops
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Computers In Society
• More impact than any other invention– Changed work and leisure activities– Used by all demographic groups
Computers In Society
• Computers are important because:– Provide information to users– Information is critical to our society– Managing information is difficult – Manage your schedule on daily and hourly basis– Manage a list of contact– Make notes on fly– Carry your data with you– Can work anywhere– Help the disables to work at home without leaving
their homes
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Computers In Society
• Computers at home– Many homes have multiple computers– Most American homes have Internet– Computers are used for
• Business• Entertainment• Communication• Education• Finance
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Computers In Society
• Computers in education– Computer literacy required at all levels
• Computers in small business– Makes businesses more profitable– Allows owners to manage– Can easily setup a business at home or a small
office– Using inexpensive computers and softwares for
promoting their businesses such as Quickbooks (accounting software) etc.
Computers In Society
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Quickbooks accounting software Quickbooks accounting software
Computers In Society
• Computers in industry– Computers are used to design products– Process control: Assembly lines are automated– Shipping
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Computers In Society
• Computers in government– Necessary to track data for population
• Police officers• Military • Tax calculation and collection
– Governments were the first computer users
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Computers In Society
• Computers in health care– Revolutionized health care– New treatments possible– Scheduling of patients has improved– Delivery of medicine is safer– Machines and devices for:
• Ultrasounds• X-Rays• MRI: Magnetic Resonance Imaging• Laser eye and kidney surgery
Computers In Society
• Computers in health care– Robotic surgical devices. Perform remote
surgery– Training surgeons using Virtual reality
technology
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Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
McGraw-Hill Technology Education
Chapter 1A
End of ChapterEnd of Chapter