HUANG Lihua, Fudan University Session 6: Computer Hardware PART I Introduction to the Foundation of Information Technologies

HUANG Lihua, Fudan University

Session 6: Computer Hardware

PART I Introduction to the Foundation of Information

Technologies

HUANG Lihua, Fudan UniversityFeb., - July., 2006

Management Challenges

1. The centralization versus decentralization debate.

2. The application backlog.


Hardware components of a computer system


The Central Processing Unit (CPU)

• Controls other parts of computer

• Arithmetic-logic unit performs principle logical/mathematical operations

• Control unit coordinates other parts, such as reading a stored program


CPU & PRIMARY STORAGE

CPUCPUPRIMARYPRIMARY

STORAGESTORAGE

DATA BUS

ADDRESS BUS

CONTROL BUS

INPUT

DEVICES

OUTPUT

DEVICES

SECONDARY

STORAGE


CENTRAL PROCESSING UNIT (CPU)

RAMRAM

PRIMARY (MAIN) MEMORYPRIMARY (MAIN) MEMORY

CONTROL UNITCONTROL UNITARITHMETIC/LOGICARITHMETIC/LOGIC

UNITUNIT

ROMROMCLOCKCLOCK


计算机中的数据处理过程：机器指令和机器周期

机器指令：

1 、取机器指令

2 、指令翻译 3 、把指令放到寄存器中

4 、把地址放到寄存器中

5 、把数据从内存中取到寄存器中

6 、命令 ALU 执行相应的操作7 、 ALU 执行操作

8 、把结果送到累加器中

指令周期

执行周期5.20


The CPU• CPU = Central Processing Unit• Instruction execution is automatic

– (tick) find memory address of next instruction– (tick) retrieve instruction from memory– (tick) decode the instruction– (tick) fetch argument from memory if necessary– (tick) execute instruction– (tick) store result in memory if necessary

• Internal clock ticks very fast (e. g., 100MHZ = 100 million ticks per second)– activities are synchronized to start on a clock tick– some activities take more than one clock tick


COMPUTER TIME

Millisecond .001 second thousand 15min 40 sec

Microsecond .001 millisecond million 11.6 days

Nanosecond .001microsecond billion 31.7 years

Picosecond .001 nanosecond trillion 31,700 years

NAME LENGTH SECOND TO 1 SECONDNAME LENGTH SECOND TO 1 SECOND

# PER COMPARED# PER COMPARED


Primary Storage

• Located near CPU• Stores all or part of active software program• Stores operating system software• Stores data the program is using• Composed of semi-conductors• RAM (random access memory): Used for short-ter

m, temporary storage• ROM (read-only memory): Semiconductor memor

y chips with program instructions


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

*


The CPU and primary storage


Microprocessors

• Semiconductor chips integrate memory, logic, and control circuits for entire CPU

• Speed depends on number of bits processed at one time; amount of data that can be moved between devices; and cycle speed (MHz)

• RISC (reduced instruction set computing) increases speed; used for scientific, workstation computing


Secondary Storage Technology

• Used for relatively long-term storage of data outside CPU

• Magnetic disk: floppies, hard disks, RAID• Optical disk: CD-ROM, CD-RW, DVD• Magnetic tape• Storage networking: direct-attached storage; net

work-attached storage; storage area networks


STORAGE AREA NETWORK (SAN)

• HIGH-SPEED NETWORK• CONNECTS VARIOUS STORAGE

DEVICES– TAPE LIBRARIES– DISK ARRAYS

STORAGE SERVICE PROVIDER: 3rd party rents storage space

*


A Storage Area Network (SAN)


Input Devices

• Keyboard and mouse

• Touch screen

• Optical character recognition

• Magnetic ink character recognition (MICR)

• Pen-based input

• Digital scanner

• Audio input

• Sensors

• Radio-frequency identification (RFID)


POINTING DEVICES

• KEYBOARD• MOUSE

– WIRED– INFRA-RED– TRACKBALL– TOUCH PAD

• JOYSTICK• TOUCH SCREEN

*

© 2002 by Prentice Hall


SOURCE DATA AUTOMATION

• Captures data in computer-readable form at the time and place the data are created

• OPTICAL CHARACTER RECOGNITION (OCR): translate designed marks, characters, and codes into digital form.– BAR CODE: Identifies products in stores, warehouses, shipments

• MAGNETIC INK CHARACTER RECOGNITION (MICR): translate characters written in magnetic ink into digital format– Special ink identifies bank, account, amount

*



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)

• *



OUTPUT DEVICES

• CATHODE RAY TUBE (CRT)

• PRINTER

• PLOTTER

• VOICE OUTPUT DEVICE

*


CATEGORIES OF COMPUTERS

• Mainframe: – Largest computer; handles massive amounts of data;

used for large business, scientific, military applications• Midrange computer:

– Smaller, less expensive minicomputers or servers; used for smaller organizations or managing networks

• Minicomputers: – Used in systems for universities, factories, research labs

• Servers: – Manage internal company networks or Web sites


CATEGORIES OF COMPUTERS

• Personal computer: – Portable or desktop microcomputer

• Workstation: – More powerful desktop computer used for computatio

n-intense tasks

• Supercomputer: – Sophisticated, powerful computer used for tasks requiri

ng rapid, complex calculations; weapons research, weather forecasting


Computer hardware trends

• Performance----better

• Price----lower

• Size----more compact

(1) The CPU

(2) Storage devices

(3) User Interfaces

(4) Type of PCs


Computer Networks and Client/Server Computing

• Distributed processing: – Distribution of processing work among

multiple computers

• Centralized processing: – Accomplished by one large central computer

• Client/server computing: – Splits processing between “clients” and

“servers” on network


Client/server computing


Types of client/server computing


Network Computers and Peer-to-Peer Computing

• Network computer (NC): – Simplified desktop computer, does not store data

permanently

• Peer-to-peer computing: – Distributed processing that links computers through

Internet or private networks

• Grid computing: – Applies computational resources of many networked

computers to solve a large, complex problem


Assignment for Session 7• Individual Preparation for session 7

– Reading Materials• Textbook: chapter 4

– P135. Review Quiz• Write down in your book, not submit

• Group Assignment: bring to class– Please design the software architecture for Mr.

Wang’s Pottery Company, including system software, application software.

– Prepare for the CASE QUESTIONS on P.121.

Documents

HUANG Lihua, Fudan University Session 6: Computer Hardware PART I Introduction to the Foundation of Information Technologies