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Lecture-4 / T. Nouf Almujally

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1 Lecture-4 / T. Nouf Almujally
COMPUTER HARDWARE Chapter 3 Lecture-4 / T. Nouf Almujally 1

2 Outline Section 1: Section 2: Peripherals: History (Homework)
Types of Computer Systems. The computer System Concept. Section 2: Peripherals: Input Technologies. Output Technologies. Storage Technologies.

3 Types of Computer Systems

4 Microcomputer Systems
Called a personal computer or PC Computing power now exceeds that of the mainframes of previous generations Relatively inexpensive Desktop, Hand-held, notebook, laptop, tablet, portable, and floor-standing Home , personal , professional , workstation or multiuser systems.

5 Recommended PC Features

6 Microcomputer Systems
Workstations - Supports heavy mathematical computing and graphics display demands Ex: - CAD in engineering, - Portfolio analysis. Network Servers - More powerful than workstations - Coordinates telecommunications and resource sharing - Supports LAN and Internet.

7 Terminals Terminal: is any input/output device connected by a network to a computer. Types: Dumb terminals: keyboard and video monitor with limited processing capabilities. Intelligent terminals: networked PCs that perform data entry and other information processing tasks. Transaction terminals: Use keyboards, touch screen, bar code scanners to capture data , while relying on servers in the network for further transaction processing. ex in banks, ATMs machines, airport check-in, POS. Dumb terminals are being phased out for more intelligent terminals

8 Terminals Network terminals:
Windows terminals: depend on network servers for Windows software, processing power and storage. Internet terminals: depend on the Internet/Intranet servers for their operating systems and application software.

9 Information Appliances
Hand-held microcomputer devices, known as personal digital assistants (PDAs). Web-enabled PDAs use touch screens, pen-based handwriting recognition, or keypads. Mobile workers use to access or the Web, exchange data with desktop PCs or Web servers. Latest entrant is the RIM BlackBerry, Apple iPhone. Information Appliances may also take the form of: Video-game consoles and other devices that connect to your home television set. Enable you to surf the WWW, , play. Telephone-based home appliances that access the web.

10 Midrange Systems High-end network servers that handle large-scale processing of business applications. Not powerful as mainframes. Less expensive to buy, operate, maintain than mainframes. First became popular as minicomputers for scientific research and industrial process monitoring. Today used in: Computer-aided manufacturing (CAM). Used as front-end servers to assist mainframes in telecommunications processing and network management.

11 Mainframe Computer Systems
Large, fast, powerful computer systems Large primary storage capacity. High transaction processing Handles complex computations Used to: Handle the information processing of major corporation and government agencies with high transaction processing. As a superservers for the large client/server networks and high- volume Internet websites for large companies. Becoming a popular computing platform for: Data mining, warehousing, electronic commerce applications

12 Supercomputer Systems
Extremely powerful computer systems designed for scientific, engineering and business applications requiring extremely high speeds for massive numeric computations. Markets for supercomputers include: Government research agencies. Large universities. Major corporations. Used for global weather forecasting, military defense, astronomy. Billions to trillions of operations per second. Millions of dollars.

13 The Computer System Concept
A computer system is an interrelated combination of components performing basic functions to provide end users with a powerful information processing tool. Input Control Computer System Processing Storage Output

14 Computer System Concept

15 Computer Processing Speeds
Early computers Milliseconds (thousandths of a second) Microseconds (millionths of a second) Current computers Nanoseconds (billionth of a second) Picoseconds (trillionth of a second) Program instruction processing speeds Megahertz (millions of cycles per second) Gigahertz (billions of cycles per second) Commonly called “clock speed”

16 Peripherals Peripheral Generic name for all input, output, and secondary storage devices Depend on direct connections to the CPU of a computer system All online devices Online Devices Separate from the CPU, but electronically connected to (and controlled by) it Offline Devices Separate from, and not under the control of, the CPU

17 Peripherals Advice for a business PC

18 Input Technologies Pointing Devices: Common input devices: Keyboard.
Examples: Electronic mouse and trackball. Pointing stick Touch pad. Touch screen.

19 Pen-Based Computing Pen-Based: Used in Tablet PCs and PDAs
They have a Pressure-sensitive layer, similar to touch screen, under liquid crystal display (LCD) screen. Software digitizes handwriting, and hand drawing. Examples: Graphics Tablet, Digitizer.

20 Speech Recognition Systems
Speech may be the future of data entry because it’s the easiest, most natural means of human communication. Recognizing speech patterns: Discrete speech recognition: requires pauses between each word. Continuous speech recognition (CSR) recognizes continuous speech.

21 Speech Recognition Software
Speech recognition systems digitize, analyze, and classify your speech and its sound patterns: Compares your speech patterns to a database of sound patterns Passes recognized words to your software Speech recognition SW requires voice recognition training Speaker-independent voice recognition systems: Allow computers to recognize words from a voice never heard before Used in voice-messaging computers, computerized telephone call switching.

22 Optical scanner, copier, fax & printer
Optical Scanning Sheet-fed scanner Flatbed scanner Optical scanner, copier, fax & printer Devices read text or graphics and convert them into digital computer input. Enables direct entry of data from source documents into a computer system. Document management library system Scans documents, then organizes and stores them for easy reference or retrieval.

23 Optical Scanning Scanners Optical Character Recognition (OCR)
Compact desktop models are popular for low cost and ease of use Larger, more expensive flatbed scanners are faster, offer high-resolution color scanning Optical Character Recognition (OCR) Software that reads characters and codes Used to read product labels, airline tickets, score tests, read bar codes

24 Other Input Technologies
Magnetic stripe Read magnetic stripe on credit cards Smart cards Microprocessor chip and memory . Digital cameras Digital Camcorder. Magnetic Ink Character Recognition (MICR) Identification numbers of bank and account printed in magnetic ink on bottom of check.

25 Output Technologies Voice Response Video Displays Printed Output
Increasingly found along with video displays in business applications Video Displays Cathode-ray tube (CRT) Liquid crystal display (LCD) Plasma displays Printed Output Inkjet , laser, multifunction model

26 Computer Storage Fundamentals
Data processed & stored in computer systems through presence or absence of signals , Either ON or OFF Uses two-state binary data representation On (1) or Off (0) Smallest element of data Bit Either 0 or 1 Group of eight bits, which operate as a single unit Byte Represents one character or number

27 Representing Characters in Bytes

28 Storage Capacity Measurement
Kilobyte (KB) One thousand bytes Megabyte (MB) One million bytes Gigabyte (GB) One billion bytes Terabyte (TB) One trillion bytes Petabyte (PB) One quadrillion bytes

29 Direct (Random) and Sequential Access
Direct Access or Random Access Directly store and retrieve data. Each storage position has unique address and can be accessed in same length of time. Semiconductor memory chips, magnetic disks. Sequential Access Data is stored and retrieved in a sequential process. Must be accessed in sequence by searching through prior data. Magnetic tape. Direct or Random Access Directly store and retrieve data Each storage position has a unique address and can be accessed in the same length of time Semiconductor memory chips, magnetic disks Sequential Access Data is stored and retrieved sequentially Must be accessed in sequence by searching through prior data Magnetic tape

30 Semiconductor Memory The primary storage (main memory) of your computer consists of microelectronic “semiconductor memory “chips. It provides you with the working storage your computer needs to process your applications. Advantages: small size, fast, shock and temperature resistance Disadvantages: volatility; must have uninterrupted electric power or the contents of the memory will be lost.  or permanently “burn in” the contents so they cannot be erased by a loss of power.

31 Types of Semiconductor Memory
Random Access Memory (RAM) Read-Only Memory (ROM) Flash Drives “Jump Drive” 1. Most widely used primary storage medium 2. Volatile memory 3. Read/write memory 1. Permanent storage 2. Can be read, but not overwritten 3. Frequently used programs (parts of OS) burned into the chips during manufacturing 4. Called firmware New type of permanent storage, can store data for unlimited periods without power. Easily transported Plugs into any USB port.

32 Hard Disk Drives & Floppy Disks (diskettes)
Magnetic Disks Used for secondary storage Fast access and high capacity Reasonable cost Types of Magnetic Disks: Floppy disks A single magnetic disk inside a plastic jacket Hard disk drives Magnetic disks, access arms, and read/write heads in sealed module. Hard Disk Drives & Floppy Disks (diskettes) Floppy disk contains 1.44 Megabytes Zip drive (similar to floppy disk) up to 750 MB Hard disks can contain hundreds of GB of storage

33 Magnetic Disks RAID (Redundant arrays of independent disks)
Disk arrays of interconnected hard disk drives. They combine from 6 to more than 100 hard disk drives into a single unit. Provide large capacities (1-2 TB or more). Provide fault tolerant with multiple copies on several disks Storage area networks (SANs) are high speed fiber channel local area networks that can interconnect many RAID units and thus share their capacity through network servers with many users.

34 Magnetic Disks Magnetic Tape:
Tape Reel Tape Cartridge Magnetic Tape: Include Tape reels, and cartridges (larger capacity). Lower-cost storage solution Used for: long term archival and backup storage

35 Optical Disks

36 Uses of Optical Disks in Business
Image Processing Long-term storage of historical image files Storage of scanned documents Publishing Medium Allows fast access to reference materials Catalogs, directories ,manuals and so on Interactive Multimedia Applications in business Multimedia encyclopedias, Video games, educational videos, and so on

37 Storage Trade-offs

38 Questions ..

39 Read from Chapter 3 (Section 1,2)
Resources .. Read from Chapter 3 (Section 1,2)

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