# 6. COMPUTERS & INFORMATION PROCESSING

```6.1
LEARNING OBJECTIVES
• IDENTIFY HARDWARE
COMPONENTS
• DESCRIBE HOW DATA IS
REPRESENTED
• CONTRAST MAINFRAMES,
MINICOMPUTERS,
SUPERCOMPUTERS, PCs,
WORKSTATIONS
6.2
*
LEARNING OBJECTIVES
• COMPARE ARRANGEMENTS OF
COMPUTER PROCESSING:
CLIENT/SERVER, NETWORK
• DESCRIBE MEDIA FOR STORING
DATA
• COMPARE INPUT/OUTPUT DEVICES
• DESCRIBE MULTIMEDIA, TRENDS
*
6.3
MANAGEMENT CHALLENGES
• WHAT IS A COMPUTER SYSTEM?
• CPU AND PRIMARY STORAGE
• COMPUTERS &amp; COMPUTER
TECHNOLOGIES
• SECONDARY STORAGE
• INPUT &amp; OUTPUT DEVICES
• INFO TECHNOLOGY TRENDS
*
6.4
COMPUTER COMPONENTS
CPU
INPUT
D
EVICES
SECONDARY
STORAGE
BUSES
OUTPUT
DEVICES
6.5
COMMUNICATIONS
DEVICES
PRIMARY
STORAGE
HOW CHARACTERS ARE STORED
• 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
6.6
EXAMPLES OF BYTES
EBCDIC
ASCII
(assume even-parity system)
C: 1100 0011 0
100 0011 1
A: 1100 0001 1
100 0001 0
T: 1110 0011 1
101 0100 1
Note how sum for each byte is an EVEN
number
*
6.7
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
*
6.8
# PER
SECOND
MEMORY SIZE
•
•
•
•
KILOBYTE (KT): 210 bytes... 1024 bytes
MEGABYTE (MB): 210 KB... “million” bytes
GIGABYTE (GB): 210 MB... “billion” bytes
TERABYTE (TB): 210 GB... “trillion” bytes
*
6.9
COMPUTER GENERATIONS
1. VACUUM TUBES: 1946-1956
6.10
COMPUTER GENERATIONS
1. VACUUM TUBES: 1946-1956
2. TRANSISTORS: 1957-1963
6.11
COMPUTER GENERATIONS
1. VACUUM TUBES: 1946-1956
2. TRANSISTORS: 1957-1963
3. INTEGRATED CIRCUITS: 1964-1979
6.12
COMPUTER GENERATIONS
1. VACUUM TUBES: 1946-1956
2. TRANSISTORS: 1957-1963
3. INTEGRATED CIRCUITS: 1964-1979
4. VERY LARGE-SCALE INTEGRATED
(VLSI) CIRCUITS: 1980- PRESENT
*
6.13
CENTRAL PROCESSING UNIT
(CPU)
CONTROL UNIT
ROM
ARITHMETIC/LOGIC
UNIT
CLOCK
PRIMARY (MAIN) MEMORY
6.14
RAM
BUSES
PRIMARY
CPU
STORAGE
DATA BUS
CONTROL BUS
6.15
INPUT
OUTPUT
SECONDARY
DEVICES
DEVICES
STORAGE
TYPES OF MEMORY
• RAM : 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
6.16
Each location can hold one BYTE
6.17
101
102
103
201
202
203
301
302
303
ALU &amp; CONTROL UNIT
• ARITHMETIC- LOGIC UNIT: CPU
component performs logic and
arithmetic operations
• CONTROL UNIT: CPU component
controls, coordinates other parts of
computer system
*
6.18
INSTRUCTION &amp; EXECUTION CYCLE
I-CYCLE:
1. FETCH
2. DECODE
3. PLACE IN INSTRUCTION REGISTER
*
6.19
INSTRUCTION &amp; EXECUTION CYCLE
E-CYCLE:
5. SEND DATA FROM MAIN MEMORY
TO STORAGE REGISTER
6. COMMAND ALU
7. ALU PERFORMS OPERATION
8. SEND RESULT TO ACCUMULATOR
*
6.20
CATEGORIES OF COMPUTERS
•
•
•
•
•
MAINFRAME
MINICOMPUTER
PERSONAL COMPUTER (PC)
WORKSTATION
SUPERCOMPUTER
*
6.21
MAINFRAME
MIPS: Millions of Instructions per second
• LARGEST ENTERPRISE COMPUTER
• 5O MEGABYTES TO OVER ONE
GIGABYTE RAM
• COMMERCIAL, SCIENTIFIC,
MILITARY APPLICATIONS
• MASSIVE DATA
• COMPLICATED COMPUTATIONS
*
6.22
MINICOMPUTER
• MIDDLE-RANGE
• 10 MEGABYTES TO OVER ONE
GIGABYTE RAM
• UNIVERSITIES, FACTORIES, LABS
• USED AS FRONT-END PROCESSOR
FOR MAINFRAME
*
6.23
MICROCOMPUTER
• DESKTOP OR PORTABLE
• 64 KILOBYTES TO OVER 128
MEGABYTES RAM
COMPUTERS
• AFFORDABLE
• MANY AVAILABLE COMPONENTS
• CAN BE NETWORKED
6.24
*
WORKSTATION
•
•
•
•
•
DESKTOP COMPUTER
POWERFUL GRAPHICS
EXTENSIVE MATH CAPABILITIES
USUALLY CONFIGURED TO
ENGINEERING, GRAPHICS)
*
6.25
SUPERCOMPUTER
TERAFLOP: TRILLION
CALCULATIONS/SECOND
•
•
•
•
•
•
HIGHLY SOPHISTICATED
COMPLEX COMPUTATIONS
FASTEST CPUs
LARGE SIMULATIONS
STATE-OF-THE-ART COMPONENTS
EXPENSIVE
*
6.26
SEQUENTIAL &amp; PARALLEL PROCESSING
SEQUENTIAL
PARALLEL
Program
Program
CPU
CPU
CPU
CPU
RESULT
RESULT
Program
CPU
6.27
RESULT
MICROPROCESSOR
VLSI CIRCUIT WITH CPU
• WORD LENGTH: bits processed at one time
• MEGAHERTZ: one million cycles per second
• DATA BUS WIDTH: bits moved between CPU &amp;
other devices
• REDUCED INSTRUCTION SET COMPUTING
(RISC): embeds most used instructions on chip to
enhance speed
• MultiMedia eXtension (MMX): enhanced Intel chip
improves multimedia applications
*
6.28
EXAMPLES OF
MICROPROCESSORS
NAME
80486
68040
PENTIUM
PENTIUM PRO
PENTIUM (MMX)
PENTIUM II
PowerPC
ALPHA
PENTIUM III
6.29
MICROPROCESSOR
MANUFACTURER
INTEL
MOTOROLA
INTEL
INTEL
INTEL
INTEL
MOTOROLA, IBM, APPLE
DEC
INTEL
WORD
LENGTH
32
32
32
32
32
32
32
64
64
DATA BUS
WIDTH
32
32
64
64
64
64
64
64
64
CLOCK SPEED
(MHz)
20 - 100
25 - 40
75 - 200
150 - 200
166 - 233
233 - 450
100 - 400
600+
500+
USES OF
MICROPROCESSORS
NAME
80486
68040
PENTIUM
PENTIUM PRO
PENTIUM (MMX)
PENTIUM II
PowerPC
ALPHA
PENTIUM III
6.30
USE
PCs
PCs
PCs
MULTIMEDIA
HIGH-END PCs, WORKSTATIONS
HIGH-END PCs, WORKSTATIONS
COMPAC &amp; DEC WORKSTATIONS
MULTIMEDIA
CENTRALIZED / DISTRIBUTED
• CENTRALIZED: PROCESSING BY
CENTRAL COMPUTER SITE
– ONE STANDARD
– GREATER CONTROL
• DISTRIBUTED: PROCESSING BY
SEVERAL COMPUTER SITES
– MORE FLEXIBILITY
6.31– FASTER RESPONSE
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
*
6.32
CLIENT / SERVER
CLIENT
REQUESTS
SERVER
DATA,
SERVICE
6.33
USER INTERFACE
DATA
APPLICATION
APPLICATION FUNCTION
FUNCTION
NETWORK RESOURCES
DOWNSIZING
TRANSFER APPLICATIONS FROM
LARGE COMPUTERS TO SMALL
• REDUCES COST
• SPEEDS RESULTS TO USER
DOES BEST
• COOPERATIVE PROCESSING
*
6.34
NETWORK COMPUTERS
• NETWORK COMPUTER: simplified
desktop computer stores minimum
data to function (uses server)
• TOTAL COST OF OWNERSHIP (TCO):
total cost of owning technology
resources (hardware, software,
support, training)
6.35
*
SECONDARY STORAGE
•DISK
•TAPE
•OPTICAL STORAGE
*
6.36
DIRECT ACCESS STORAGE DEVICE
• HARD DISK: Steel platter array for
large computer systems
• RAID: Redundant array of
Inexpensive Disks
• FLOPPY DISK: Removable disk for
PC
*
6.37
DISK PACK STORAGE
•
•
•
•
•
•
LARGE SYSTEMS
RELIABLE STORAGE
LARGE AMOUNTS OF DATA
QUICK ACCESS &amp; RETRIEVABLE
TYPICAL: 11 2-SIDED DISKS
CYLINDER: SAME TRACK ALL SURFACES
DISK 1
DISK 2
DISK 3
DISK 4
DISK 5
CYLINDER 10: TRACK 10 (TOP AND BOTTOM OF EACH DISK)
6.38
TRACKS AND SECTORS
TRACKS
EACH TRACK HOLDS
SAME AMOUNT OF DATA
START
OF
TRACKS
SECTOR
6.39
DIRECTORY ON TRACK 0
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
6.40
*
MAGNETIC TAPE
• 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
*
6.41
IBG
BLOCK 1
BLOCK 2
BLOCK 3
MAGNETIC CARTRIDGE
• ENCLOSED FERROUS OXIDE TAPE
• USED PERIODICALLY TO BACK UP
RECORDS
• INEXPENSIVE
• STORED IN SAFE LOCATION
• CAN BE REUSED
*
6.42
PERIPHERAL DEVICES
• POINTING DEVICES
• SOURCE DATA AUTOMATION
• OUTPUT DEVICES
*
6.43
POINTING DEVICES
• KEYBOARD
• MOUSE
– WIRED
– INFRA-RED
– TRACKBALL
• JOYSTICK
• TOUCH SCREEN
6.44
*
SOURCE DATA AUTOMATION
CAPTURES DATA IN COMPUTER FORM AT
TIME &amp; 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
6.45
*
SOURCE DATA AUTOMATION
• PEN-BASED INPUT: digitizes signature
• DIGITAL SCANNER: translates images &amp;
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)
*
6.46
OUTPUT DEVICES
•
•
•
•
•
CATHODE RAY TUBE (CRT)
PRINTER
PLOTTER
VOICE OUTPUT DEVICE
MULTIMEDIA
*
6.47
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.
6.48
*
BATCH PROCESSING
KEYBOARD INPUT
BATCH OF
TRANSACTIONS
SORTED
TRANSACTION FILE
OLD MASTER
FILE
VALIDATE AND UPDATE
ERROR
REPORTS
6.50
NEW
MASTER FILE
REPORTS
ON-LINE PROCESSING
TRANSACTIONS
KEYBOARD
IMMEDIATE
INPUT
6.50
PROCESS /
UPDATE
MASTER FILE
IMMEDIATE
PROCESSING
MASTER
FILE
IMMEDIATE
FILE UPDATE
TECHNOLOGY TRENDS
•
•
•
•
•
•
•
•
INTERACTIVE MULTIMEDIA
VIRTUAL REALITY
ENHANCED WORLD WIDE WEB
SUPERCHIPS
FIFTH GENERATION COMPUTERS
MASSIVELY PARALLEL COMPUTERS
SMART CARDS
MICROMINIATURIZATION
6.51
*
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