Transcript PowerPoint 簡報 - National University of Kaohsiung

Introduction to Computer Science
(I)
Inside the Computer
T. K. Yin, NUK-CSIE
Computer System
• A computer system consists of
– Hardware: The set of electronic elements
required to run programs
– Software: The set of instructions to be run on
the hardware
– Data: Raw facts as input to the computer. After
processed, useful information as the output of
the computer is produced
– User
T. K. Yin, NUK-CSIE
Binary Digits: 1 and 0
• Types of signals
– Analog: Continuous waveforms in which
variations in frequency and amplitude can be
used to represent information
– Digital: Discrete signals in two states.
Generally, the on state is expressed or
represented by the number 1 and the off state
by the number 0
T. K. Yin, NUK-CSIE
• Digitalized data in computers
–
–
–
–
–
–
Letters
Numbers
Colors
Sounds
Images
Odors
• Bit: An on or off electronic state
– On-bit: 1
– Off-bit: 0
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• On and off states inside the computers
– RAM: Presence or absence of an electrical
charge in an integrated circuit
T. K. Yin, NUK-CSIE
Source: http://www.intel.com/research/silicon/nanotechnology.htm
– Disk storage: Two states are represented by the
magnetic arrangement of the surface coating on
magnetic disks
Source: http://www.research.ibm.com/resources/news/20010518_whitepaper.shtml
T. K. Yin, NUK-CSIE
– CD and DVD: Digital data are stored
permanently as microscopic pits
Source: http://www.opticaldisc-systems.com/2002SepOct/DVDBASICS80.htm
T. K. Yin, NUK-CSIE
– Fiber optic cable: Binary data are pulses of light
– Electrical transmission media: Binary numbers
are electrical signals
Source: http://www.bsu.edu/web/CBTHORNBERRY/trends5.html
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• Character encoding systems: bits and bytes
– Byte: The 8-bit combination of bits are used to
represent a character
– ASCII: The 7-bit ASCII (American Standard
Code for Information Interchange) code can
represent up to 128 characters
T. K. Yin, NUK-CSIE
Source: http://www.unicode.org/charts/PDF/U0000.pdf
– Unicode: A 16-bit encoding system to represent
more characters than the English language
Source: http://www.unicode.org/charts/PDF/U4E00.pdf
T. K. Yin, NUK-CSIE
The Components of A Computer
• Von Neumann architecture
– The model of computing proposed by John Von
Neumann (1903-1957) in 1946
– The stored program computer
• The instructions that control the operation of the
computer be encoded as binary values and stored
internally in the memory unit along with the data
– The basis of the structure and organization of
virtually all modern computers
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– Include four major subsystems called memory,
input/output, the arithmetic/logic unit (ALU),
and the control unit
Memory
Control unit
ALU
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Processor
Memory
– The first stored program
• Maurice Wilkes of the University of Cambridge
created the first stored program on a machine, called
EDSAC, which calculated and printed the table of
squares on May 6, 1949.
Image courtesy of Computer History Museum, http://www.computerhistory.org
T. K. Yin, NUK-CSIE
• The major devices of a personal computer
–
–
–
–
The PC system unit
Storage devices
Input devices
Output devices
Storage
Devices
Input
Devices
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CPU
Control Unit
ALU
Main Memory
System Unit
Output
Devices
The PC System Unit
• The motherboard
– A single circuit board provides the path through
which the processor communicates with
memory components and peripheral devices
– Attached devices
•
•
•
•
Processor
Support electronic circuitry, such as the chipset
Memory chips
Expansion boards
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1: Processor socket
2: DIMM sockets
6
1
7
3. Floppy connector
4: Hard disk connectors
5: Chipset
5
2
6: PCI expansion slots
7: AGP video cord slot
4
T. K. Yin, NUK-CSIE
Source: http://www.asus.com
3
1: PS/2 mouse port
7: USB 2.0 ports 1 and 2
2: Parallel port
8: VGA por
3: RJ-45 port
9: S/PDIF out port (digital audio)
4: Line In port
10: USB 2.0 ports 3 and 4
5: Line Out port
11: PS/2 keyboard port
6: Microphone port
T. K. Yin, NUK-CSIE
Source: http://www.asus.com
• The processor
– Called the central processing unit or CPU
– The nucleus of any computer system
– Contains the control unit and the arithmetic and
logic unit
– Companies
•
•
•
•
•
•
Intel: Pentium 4, Celeron, Xeon, Itanium
Motorola: 680x0
AMD: K6, Duron, Athlon
Apple/Motorola/IBM: Power PC
Sun: SPARC
Compaq: Alpha
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• DRAM (dynamic random access memory)
– A high-speed holding area for data and
programs
– Types
•
•
•
•
SDRAM (synchronous DRAM)
VCM (virtual channel memory)
DRDRAM (direct rambus DRAM)
DDR SDRAM (double data rate SDRAM)
– Module
• SIMM (single in-line memory module)
• DIMM (double in-line memory module)
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VCM
DRDRAM
DDR SDRAM
200 PIN
DDR333 256MB
SO-DIMM
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• Cache memory
– Level 1 cache: Built into the processor
– Level 2 cache: On another chip, sitting between the
processor and RAM
• Volatile memory
– DRAM
– SRAM (static RAM): Used in cache memory
• Nonvolatile memory
– ROM (read only memory)
• When you turn on a microcomputer system, aprogram in ROM
automatically readies the computer for use and produces the
initial display-screen prompt
– PROM (programmable ROM)
– Flash memory
• The PC’s BIOS (basic input output system) is stored in flash
memory
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• CMOS (complementary metal-oxide semiconductor )
– A type of memory chip with very low power requirements,
and in PCs it operates using small batteries. In PCs,
CMOS is more specifically referred to as CMOS RAM.
– Store information your computer needs when it boots up,
such as hard disk types, keyboard and display type, chip
set, and even the time and date.
T. K. Yin, NUK-CSIE
T. K. Yin, NUK-CSIE
• Buses and ports
– The motherboard and its system bus must be linked to
input, output, storage, and communication devices to
receive data and return the results of processing
– PCI local bus
• The PCI local bus (peripheral component interconnect) enables
circuit boards with extra features to be linked to the common
system bus
– AGP bus
• The AGP bus (accelerated graphics port) is a special-function
bus designed to accommodate the throughput demands of highresolution 3-D graphics
T. K. Yin, NUK-CSIE
– USB
• The USB (universal serial bus) is the primary standard for
connecting peripheral devices to a PC
• The USB hub is a device connecting to a USB port and
offering three, four, or five additional USB ports
• USB 2.0 permits data transfer at 480 Mbps, about 40 times
faster than the original USB standard
– 1394 or FireWire bus
• The 1394 bus supports data transfer rates of 400 Mbps for the
original standard and 800 Mbps for the current standard
– SCSI bus
• The SCSI bus (small computer system interface) was an early
alternative to using expansion slots to extend PC functionality
• Up to 15 SCSI peripheral devices can be daisy-chained to a
SCSI interface expansion card via the SCSI port
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– Serial port
• The 9-pin or 25-pin RS-232C connector
• An external modem might be connected to a serial
port
– Parallel port
• Parallel ports use the same 25-pin RS-232C
connector
• Printers used parallel ports
– IrDA port
• The infrared port transmits data via infrared light
waves
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USB connector
1394/FireWire connector
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PS/2 keyboard connector
Ethernet connector
SCSI cable
Video/monitor cable
Printer connector
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• Expansion boards
– Graphic adapter
• Normally an AGP board
– Sound
• Typically has receptacles for a microphone, a
headset, an audio output and most has a port for a
game controller and a MIDI (music instrument
digital interface) port
–
–
–
–
Data/voice/fax modem
Network interface card
SCSI interface card
Video capture card
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Sound card
Graphics adapter
SCSI interface card
Network interface card
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• PC cards
– The PCMCIA card is a credit card-sized
removable expansion module that is plugged
into an external PCMCIA expansion slot on a
PC, usually a notebook
– Extended RAM, programmable nonvolatile
flash memory, network interface cards (wireless
and wired), data/voice/fax modems, hard-disk
cards
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PCI card and PCMCIA radio card
PCMCIA hard disk
PCMCIA wireless network
interface card
PCMCIA flash memory
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• Processor description
– Word size: bits handled as a unit
• 32 bits
• 64 bits
– Core speed
• PCs
– MHz (millions of clock cycles per second)
– GHz (billions of clock cycles per second)
• PCs, workstations, server computers
– MIPS (millions of instructions per second)
• Supercomputers
– FLOPS (floating point operations per second)
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– Bus speed
• MHz
• GHz
• Memory capacity
–
–
–
–
Kilobytes (KB): 1024 ( 210 ) bytes
Megabytes (MB): 1,048,576 ( 2 20 ) bytes
30
2
Gigabytes (GB):
bytes
Terabytes (TB):
2 40 bytes
T. K. Yin, NUK-CSIE
Storage Devices
• Magnetic disk storage
– Fixed disks
• Hard disks
– Interchangeable disks
• Floppy disks: 1.44 MB
• SuperDisk: 120 MB
• Zip disks: 100, 250, 750 MB
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Floppy disk
Hard disk
Zip disk
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Superdisk
• Optical laser discs
– CD formats (650MB)
• CD audio (compact disc): 4.72 inch
• CD-ROM (compact disc-read-only memory)
– 32X, 40X, 75X: Spin at 32, 40, and 75 times the speed of
the original CD standard
– Original 1X CD-ROM data transfer rate: 150 KB per
second
– Spin more quickly when accessing the data near the center
(about 450 rpm) and more slowly for data near the edge
(about 250 rpm)
• CD-R (compact disc recordable)
• CD-RW (CD-ReWritable)
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– DVD formats (4.7 GB or 9.4 GB for double
sided)
• DVD (digital video disc) audio, DVD video
• DVD-ROM
– The data transfer rate is nine times that of a CD-ROM
spinning at the same rae
• DVD+R, DVD-R: Like CD-R
• DVD+RW, DVD-RW: Like CD-RW
– DVD-RW (DVD-R) and DVD_RW (DVD+R) are
competing technologies
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CD-R disc
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DVD-RW disc
• Solid state storage
– Flash memory
• Mini USB drive
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Input Devices
• Keyboard
• Mouse
• Point-and-draw devices
– Trackpad: Common on notebook PCs
– Trackpoint: Usually positioned in or near a notebook’s
keyboard
– Trackball: A ball inset in a notebook PC or as a separate
unit
– Joystick
– Digitizer tablet and pen
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Keyboard
Trackpad
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Mouse
Trackpoint
Trackball
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Joystick
Digitizer tablet and pen
• Scanner
– Handheld label scanner
• Read data on price tags, shipping labels, inventory
part numbers, book ISBNs
• Sometimes called wand scanners
– Stationary label scanner
• Applications like wand scanners
• Common in grocery stored and discount stores
– Document scanner
• Scans documents of varying sizes
• Read envelopes at the U.S. Postal Service, and also
read turnaround documents for utility companies
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Stationary label scanner
Handheld label scanner
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Document scanner
• Image scanner
– Page image scanner
• The scanned result is a high-resolution digitized image
– Hand image scanner
• Rolled manually over the image to be scanned
• Badge reader (for magnetic stripes and smart cards)
– The magnetic stripes on the back of charge cards and
badges offer another means of data entry
• Speech recognition
– Consists of software, a generic vocabulary database,
and a high-quality microphone with noise-canceling
capabilities
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Hand image scanner
Page image scanner
Badge reader
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Speech recognition
• Digital camera
• Desktop digital video camera
– Webcam
• Digital video cameras that are continuously linked
to the Internet
– Real-time Internet-based videophone
conversations
• Digital camcorder
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Webcam
Digital camera
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Digital camcorder
Output Devices
• Monitors
– CRT
– Flat-panel
• LCD (liquid crystal display): Active matrix or
passive matrix
• TFT (thin film transistor) LCD: Active matrix
– Touch screen
• Has pressure-sensitive overlays that can detect
pressure and the exact location of that pressure
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– Monitor resolution
• The number of pixels that can be displayed
– 1024*768
• The number of bits used to represent each pixel
– 8-bit color mode: 256 colors
– 16-bit high-color mode: 65,536 colors
– True color, either 24-bit or 32-bit mode
• The dot pitch of the monitor
– Dot pitch: The distance between the centers of adjacent
pixels
– .28 mm, .25 mm
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CRT monitor
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TFT LCD monitor
Touch screen monitor
• LCD projector
• Printer
– Laser
• Nonimpact
• 600 dpi (dots per inch), 1200 dpi
– Ink-jet
• Nonimpact
• The droplets, ehich dry instantly as dots, form the
letters and images
– Large-format ink-jet, or plotter
– All-in-one multifunction device: Print, fax, scan,
and copy
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LCD projector
Ink-jet printer
Large-format ink-jet printer
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Laser printer
Multifunction device
• Sound System
– Small speaker
– 6.1 sound system
• Voice-response system
– Recorded voice
– Speech synthesis
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References
• Computers
– Larry Long & Nancy Long, Twelfth Edition, Pearson Education, Inc
• Invitation to Computer Science, C++ Version
– G. Michael Schneider & Judith L. Gersting, Third Edition, Course
Technology
• Computer History Museum
– http://www.computerhistory.org
• http://archive.computerhistory.org/
T. K. Yin, NUK-CSIE