Transcript Computer H/W Review

INFORMATION TECHNOLOGY MANAGEMENT
資訊技術應用 Session 6
OUTLINE
 Logistics
• Review revised schedule
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
Concept review
(O) Ch2 & (L)Ch5: computer H/W terminology
review. (Focus on terminology)
• Computer categories & their generations/appl
• Computer system config.
• Centralized vs de-centralized / Client-server config / NC
• Computer systems & components
• Trends in H/W.
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Computer categories & their generations
• by computing power/size: (micro - mid range mainframe) (fg 2.1)
supercomputer/mainframe/mini(work
station)/micro/portable/NB/palm-top
• by usage: generic vs specific (embedded system)
(eg: inventory counting/car rental)
• by comp relationship: network server vs client;
workstation; host vs device;
• by generations: 1st - 5th gen (fg 2.2)
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CATEGORIES OF COMPUTERS
Some examples (by history)
SUPERCOMPUTER
 MAINFRAME
 MINICOMPUTER
 WORKSTATION
 PERSONAL COMPUTER (PC)
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MAINFRAME
LARGEST COMPUTER; several cabinets
 5O MEGABYTES TO OVER ONE
GIGABYTE RAM
 Typical applications:
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• COMMERCIAL, SCIENTIFIC, MILITARY
APPLICATIONS
• COMPLICATED COMPUTATIONS ;
computation intensive
• transaction-based, heavy-duty data processing,
• large # of users; large amount of data
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MINICOMPUTER
MIDDLE-RANGE; single cabinet
 10 MEGABYTES TO OVER ONE
GIGABYTE RAM
 Typical applications:
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• UNIVERSITIES, FACTORIES, LABS
• USED AS FRONT-END PROCESSOR FOR
MAINFRAME
• Engineering applications, ..
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MICROCOMPUTER & Laptops
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DESKTOP OR PORTABLE
64 KILOBYTES TO OVER 128 MEGABYTES
RAM
AFFORDABLE
Typical appl:
• PERSONAL OR BUSINESS
COMPUTERSMANY AVAILABLE
COMPONENTS
• CAN BE NETWORKED
• office appl., personal use, ..
• Desk-top/Lap-top/Portable
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WORKSTATION
DESKTOP COMPUTER
 POWERFUL GRAPHICS
 EXTENSIVE MATH CAPABILITIES
 MULTI-TASKING
 USUALLY CONFIGURED TO SPECIAL
FUNCTION (e.g.; CAD, ENGINEERING,
GRAPHICS)
 Typical appl:
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• Engineering / technical computation
*
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SUPERCOMPUTER
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HIGHLY SOPHISTICATED
COMPLEX COMPUTATIONS
FASTEST & multiple CPUs
STATE-OF-THE-ART COMPONENTS
EXPENSIVE
Parallel computation (H/W & S/W)
Typical appl:
• LARGE SIMULATIONS (eg.: Nuclear explosion)
• Extremely computation intensive
• (Weather / image processing, etc.)
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COMPUTER GENERATIONS
1. VACUUM TUBES:
1946-1956
2. TRANSISTORS:
1957-1963
3. INTEGRATED CIRCUITS: 1964-1979
4. VERY LARGE-SCALE INTEGRATED
CIRCUITS (VLSI):
1980- PRESENT
ULSI (Ultra Large-scale)
5. ???
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Commonsense Measures
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BIT /BYTE/WORD
• EBCDIC- Extended Binary Coded Decimal Interchange Code (8 bits per
byte)
• ASCII- American Standard Code for Information Exchange (7 or 8 bits
per byte)
MEMORY SIZE
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KILOBYTE (KT): 210 bytes... 1024 bytes
MEGABYTE (MB): 210 KB... “million” bytes
GIGABYTE (GB): 210 MB... “billion” bytes
TERABYTES (TB): 210 GB... “trillion” bytes
COMPUTER TIME
Millisecond
Microsecond
Nanosecond
Picosecond
10-3 second
10-6 second
10-9 second
10-12 second
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CLIENT / SERVER
NETWORKED COMPUTERS
 CLIENT: user (PC, workstation, laptop) requires data, application,
communications it does not have
 SERVER: component (computer) having desired data, application,
communications
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CLIENT
SERVER
REQUESTS
DATA,
SERVICE
USER INTERFACE
DATA
APPLICATION
FUNCTION
APPLICATION FUNCTION
NETWORK RESOURCES
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CENTRALIZED / DECENTRALIZED
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CENTRALIZED: PROCESSING BY CENTRAL
COMPUTER SITE
• ONE STANDARD
• GREATER CONTROL
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DECENTRALIZED: PROCESSING BY
SEVERAL COMPUTER SITES LINKED BY
NETWORKS
• MORE FLEXIBILITY
• FASTER RESPONSE
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NETWORK COMPUTERS
NETWORK COMPUTER: simplified desktop
computer stores minimum data to function (uses
server)
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Computer systems & components
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The system relationship:
– Input / processing / Output / storage / control (fg 2.9)
– CPU & peripheral
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Components
• CPU:
• Primary Storage
– Where your program & data must reside before
program is run.
– RAM / ROM / EPROM /EEPROM
• Peripherals
– all I/O devices and secondary storage devices. Online
devices under CPU control.
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COMPUTER COMPONENTS
PRIMARY
CPU
STORAGE
DATA BUS
ADDRESS BUS
CONTROL BUS
INPUT
OUTPUT
SECONDARY
DEVICES
DEVICES
STORAGE
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MICROPROCESSOR
VLSI CIRCUIT WITH CPU
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WORD LENGTH: bits processed at one time
MEGAHERTZ: one million cycles per second
DATA BUS WIDTH: bits moved between CPU & other
devices
Bandwidth: Speed of data transmission.
REDUCED INSTRUCTION SET COMPUTING
(RISC): embeds most used instructions on chip to
enhance speed
MultiMedia eXtension (MMX): enhanced Intel chip
improves multimedia applications
MIPS: Million Instruction Per Second
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EXAMPLES OF
MICROPROCESSORS
NAME
80486
68040
PENTIUM
PENTIUM PRO
PENTIUM (MMX)
PENTIUM II
PowerPC
ALPHA
MICROPROCESSOR
WORD DATA BUS CLOCK SPEED
MANUFACTURER
LENGTH
WIDTH
(MHz)
INTEL
32
32
20 - 100
MOTOROLA
32
32
25 - 40
INTEL
32
64
75 - 200
INTEL
32
64
150 - 200
INTEL
32
64
166 - 233
INTEL
32
64
233 - 450
MOTOROLA, IBM, APPLE
32
64
100 - 250+
DEC
64
64
300+
=> Clock-less computer (asynchronous vs synchronous)
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TYPES OF MEMORY
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RAM : Random Access Memory
• Dynamic: Changes thru processing
• Static: Remains constant (power on)
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ROM : Read Only Memory (preprogrammed)
• PROM: Program can be changed once
• EPROM: Erasable thru ultraviolet light
• EEPROM: Electrically erasable
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Mask ROM
Volatile vs Non-volatile
Flash memory
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SEQUENTIAL & PARALLEL PROCESSING
SEQUENTIAL
PARALLEL
Program
Program
TASK 1
CPU
CPU
CPU
CPU
TASK 1
TASK 2
TASK 3
RESULT
Program
RESULT
TASK 2
CPU
RESULT

vs. Multi-tasking. (Is it really true ?)
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SECONDARY STORAGE
DISK
TAPE
OPTICAL STORAGE
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DISK PACK STORAGE
 LARGE
SYSTEMS
 RELIABLE STORAGE
 LARGE AMOUNTS OF DATA
 QUICK ACCESS & RETRIEVABLE
 TYPICAL: 11 2-SIDED DISKS
 CYLINDER: SAME TRACK ALL SURFACES
DISK 1
DISK 2
DISK 3
DISK 4
DISK 5
READ/WRITE
HEADS
CYLINDER 10: TRACK 10 (TOP AND BOTTOM OF EACH DISK)
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TRACKS AND SECTORS
EACH TRACK HOLDS
SAME AMOUNT OF DATA
TRACKS
START
OF
TRACKS
SECTOR
DIRECTORY ON TRACK 0
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OPTICAL STORAGE
CD-ROM:
500-660 MEGABYTES
• LAND: flat parts of disk surface reflects light
• PITS: small scratch on surface scatters light
WRITE
ONCE / READ MANY (WORM):
• CD-R: Compact Disk - Recordable
• CD-RW: CD - Rewritable
DIGITAL VIDEO
DISK (DVD): CD size,
up to 10 gigabytes of data
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MAGNETIC TAPE or CARTRIDGE
 STANDARD
FOR SEQUENTIAL FILES
 SPOOL OF PLASTIC TAPE COVERED WITH
FERROUS OXIDE (2400 feet per spool)
 RECORD GROUPS: BLOCKING FACTOR (e.g., 10
records per block)
 GROUPS SEPARATED BY INTER-BLOCK GAP
 RECORDS READ BLOCK AT A TIME
 USED PERIODICALLY TO BACK UP RECORDS
 INEXPENSIVE
HEADER
IBG
BLOCK 1
BLOCK 2
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PERIPHERAL DEVICES
POINTING DEVICES
 SOURCE DATA AUTOMATION
 OUTPUT DEVICES
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POINTING DEVICES
• KEYBOARD
• MOUSE
–
–
–
–
WIRED
INFRA-RED
TRACKBALL
TOUCH PAD
• JOYSTICK
• TOUCH SCREEN
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SOURCE DATA AUTOMATION
CAPTURES DATA IN COMPUTER FORM AT TIME & PLACE
OF TRANSACTION
 OPTICAL CHARACTER RECOGNITION (OCR): saves
characters, format
 BAR CODE: identifies products in stores, warehouses,
shipments
 MAGNETIC INK CHARACTER RECOGNITION (MICR):
special ink identifies bank, account, amount
 PEN-BASED INPUT: digitizes signature
 DIGITAL SCANNER: translates images & characters into
digital form
 VOICE INPUT DEVICES: converts spoken word into digital
form
 SENSORS: devices that collect data from environment for
computer input (e.g., thermometers, pressure gauges)
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OUTPUT DEVICES &
DATA PROCESSING
OUTPUT DEVICES
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CATHODE RAY TUBE (CRT)
PRINTER
– Impact: dot matrix, line printer
– Non-impact: laser, inkjet
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PLOTTER
VOICE OUTPUT DEVICE
MULTIMEDIA
DATA PROCESSING
• BATCH PROCESSING: transaction data stored until
convenient to process as a group. Useful for less time-sensitive
actions.
• ON-LINE PROCESSING: transaction data entered directly into
system, constantly updating files. Requires direct-access
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devices.
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Additional Basic Terms
 FLOPS/MIPS
 CD/HD/FD
 dump
terminal vs intelligent terminal
 Fault tolerant capability
 Disk shadowing
 Disk array
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Trends
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faster / cheaper / smaller (MICROMINIATURIZATION) /
more reliable / easier UI
INTERACTIVE MULTIMEDIA
VIRTUAL REALITY
ENHANCED WORLD WIDE WEB
SUPERCHIPS
FIFTH GENERATION COMPUTERS
MASSIVELY PARALLEL COMPUTERS
SMART CARDS
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Fig. 2.15; Fig. 2.24.
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