Transcript 6. computers & information processing

LEARNING OBJECTIVES
• Identify Computer Components
• Describe Data Representation
• Contrast mainframes,
minicomputers, supercomputers,
PCs, workstations
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LEARNING OBJECTIVES
• Compare arrangements of computer
processing: Client/Server, network.
• Describe media for storing data
• Describe Input/Output Devices
• Describe multimedia, trends
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Computer Components
CPU
INPUT
DEVICES
SECONDARY
STORAGE
BUSES
OUTPUT
DEVICES
COMMUNICATIONS
DEVICES
PRIMARY
STORAGE
How Characters are Presented
• BIT: Binary Digit. On/Off, 0/1, Magnetic/Not
• BYTE: Group of bits for one character
– EBCDIC- Extended Binary Coded Decimal
Interchange Code (8 bits per byte)
– ASCII- American Standard Code for
Information Exchange (7 or 8 bits per
byte)
• PARITY BIT: extra bit added to each byte
to help detect errors
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EXAMPLES OF BYTES
EBCDIC
ASCII
Decimal
(assume even-parity system)
C: 1100 0011 0
A: 1100 0001 1
T: 1110 0011 1
100 0011 1
100 0001 0
101 0100 1
67
65
84
Parity bit
Note how sum for each byte is an EVEN number
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Computer Time
NAME
Millisecond
LENGTH
.001 second
COMPARED
TO 1 SECOND
thousand 15min 40 sec
Microsecond .001 millisecond
million
11.6 days
Nanosecond .001microsecond
billion
31.7 years
Picosecond
trillion
31,700 years
.001 nanosecond
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5.7
# PER
SECOND
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
Differentiated by exponential power
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5.8
COMPUTER GENERATIONS
1. VACUUM TUBES: 1946-1956
5.9
COMPUTER GENERATIONS
1. VACUUM TUBES: 1946-1956
2. TRANSISTORS: 1957-1963
5.10
COMPUTER GENERATIONS
1. VACUUM TUBES: 1946-1956
2. TRANSISTORS: 1957-1963
3. INTEGRATED CIRCUITS: 1964-1979
5.11
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
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5.12
Terms for Microprocessors
• Word Length: bits processed at one time (e.g., 32bit processor)
• MEGAHERTZ: processing speed; one million
cycles per second (e.g., 1GHz)
• Data Bus Width: bits moved between CPU & other
devices (e.g., 133MHz motherboard)
• RISC: Reduced Instruction Set Computing:
embeds most used instructions on chip to
enhance speed (80/20 rule)
• MultiMedia eXtension (MMX), 3D-Now!: special
codes for improving multimedia applications
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5.12
CENTRAL PROCESSING UNIT
(CPU)
CONTROL UNIT
ROM
ARITHMETIC/LOGIC
UNIT
CLOCK
PRIMARY (MAIN) MEMORY
5.14
RAM
BUSES
PRIMARY
CPU
STORAGE
DATA BUS
ADDRESS BUS
CONTROL BUS
5.15
INPUT
OUTPUT
SECONDARY
DEVICES
DEVICES
STORAGE
TYPES OF MEMORY
• RAM (Working Area): Random Access
Memory
– Dynamic: Changes thru processing
– Static: Remains constant (power on)
• ROM : Read Only Memory
(preprogrammed)
– PROM: Program can be changed once
– EPROM: Erasable thru ultraviolet light
– EEPROM: Electrically erasable
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5.16
ADDRESSES IN MEMORY
Each location has an ADDRESS
Each location can hold one BYTE
5.17
101
102
103
201
202
203
301
302
303
ALU & CONTROL UNIT
• Arithmetic-Logic UNIT: CPU
component performs arithmetic
(calculation) and logic (branching,
decision) operations
• Control Unit: CPU component
controls, coordinates other parts of
computer system (traffic cop)
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5.18
Examples of
Microprocessors
• Intel: PII, PIII (up to 1GHz), P4
• AMD: Athlon, Athlon Thunderbird (up
to 1.2GHz), Duron (~800MHz)
• Transmeta: Caruso (code morphing,
lower power consumption) for laptop
and handheld devices
• Motorola: Chips for Power Mac
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5.18
CATEGORIES OF COMPUTERS
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MAINFRAME
MINICOMPUTER
PERSONAL COMPUTER (PC)
WORKSTATION
SUPERCOMPUTER
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5.23
MICROCOMPUTER
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•
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Desktop or Portable
64 to 256 Megabytes of RAM
Personal or business use
Affordable
“Assembled” (not “manufactured”) from
many components (modular combination)
• Can be networked
• “Decentralization” from mainframe use
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5.26
WORKSTATION
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Desktop Computer
Powerful graphics
Extensive math capabilities
Multi-tasking
Usually configured to special functions
such as CAD, ENGINEERING, GRAPHICS
• Distinction from PC has been blurred
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5.27
SEQUENTIAL & PARALLEL PROCESSING
SEQUENTIAL
PARALLEL
Program
Program
TASK 1
CPU
CPU
CPU
CPU
TASK 1
TASK 2
TASK 3
RESULT
RESULT
Program
TASK 2
CPU
5.29
RESULT
CENTRALIZED / DECENTRALIZED
• CENTRALIZED: Processing by central
computer site
– One standard
– Greater control
• DECENTRALIZED: Processing by several
computer sites linked by networks
– More flexibility
– Faster response
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CLIENT / SERVER
• NETWORKED COMPUTERS
• CLIENT: where things are processed.
User (PC, workstation, laptop) requires
data, application, communications it does
not have
• SERVER: hosting data and application,
handle communications and other
administrative works.
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5.31
CLIENT / SERVER
CLIENT
REQUESTS
SERVER
DATA,
SE
RVICE
5.32
USER INTERFACE
DATA
APPLICATION
FUNCTION
APPLICATION FUNCTION
NETWORK RESOURCES
Cost Reduction through
Task Redistribution
• Network Computer: NetPC (MS) and NC
(IBM et al.) smart terminals
• Appliance Computing: e.g., WebTV.
Total Cost of Ownership (TCO): must
consider more than just the equipment
price. Include costs in hardware,
software, upgrades, maintenance,
technical support, training
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SECONDARY STORAGE
•Disk
•Tape
•Optical storage
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5.35
TRACKS AND SECTORS
TRACKS
EACH TRACK HOLDS
SAME AMOUNT OF DATA
START
OF
TRACKS
SECTOR
DIRECTORY ON TRACK 0
5.37
Source: Senn, Information Technology in Business1995
OPTICAL STORAGE
• CD-ROM: 500-660 MEGABYTES
• 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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5.38
MAGNETIC CARTRIDGE
• ENCLOSED FERROUS OXIDE TAPE
• USED PERIODICALLY TO BACK UP
RECORDS
• INEXPENSIVE
• STORED IN SAFE LOCATION
• CAN BE REUSED
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5.40
Peripheral Devices
• POINTING DEVICES
• SOURCE DATA AUTOMATION
• OUTPUT DEVICES
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5.41
Pointing Devices
• KEYBOARD
• MOUSE
– WIRED
– INFRA-RED
– TRACKBALL
– TOUCH PAD
• JOYSTICK
• TOUCH SCREEN
5.42
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Source Data Automation
CAPTURES DATA IN COMPUTER FORM AT
TIME & PLACE OF TRANSACTION
• OPTICAL CHARACTER RECOGNITION
(OCR)
• BAR CODE
• MAGNETIC INK CHARACTER
RECOGNITION (MICR)
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SOURCE DATA AUTOMATION
• 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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5.44
Output Devices
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CATHODE RAY TUBE (CRT)
PRINTER
PLOTTER
VOICE OUTPUT DEVICE
MULTIMEDIA
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5.45
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
devices. “Interactive”
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TRANSISTORS PER CHIP
TECHNOLOGY TRENDS
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INTERACTIVE MULTIMEDIA
VIRTUAL REALITY
ENHANCED WORLD WIDE WEB
SUPERCHIPS
FIFTH GENERATION COMPUTERS
MASSIVELY PARALLEL COMPUTERS
SMART CARDS
MICROMINIATURIZATION
5.49
YEARS
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