The Organization and Information Management

1
Computer Hardware
Computers and components
2
(No Transcript)
3
(No Transcript)
4
Basic Computer System
Processor
ALU
CNTL
.....
I/O module
Interconnections
BUS
CONTROLLER
MAIN MEMORY
BUS
ATTACHED DEVICE
5
Computer Components
6
CPU Cycle
Increment Program Counter
FETCH
EXECUTE
FETCH
EXECUTE
Halt
Start
7
Execution Cycle
8
Instruction SetsComplex (CISC) or Reduced (RISC)
INSTRUCTIONS
ROM
9
Measuring Processing Power

• Clock Speed
• Instruction Speed
• Word Length and Bus Width
• Speed of Arithmetic
• Instruction Set
• Pipelining

10
Primary Storage

• Volatile
• DRAM
• SRAM
• Cache
• Nonvolatile
• ROM

11
Measuring Storage (bytes)

• Kilobytes KB 1,000 B
• Text document
• Megabytes MB 1,000,KB
• Images
• Gigabytes GB 1,000 MB
• Hard disk drives
• Terabytes TB Trillions
• Data warehouse files

12
Attached I/O Devices

• Secondary Storage
• DASD
• Tape
• Removable Electronic Storage
• Optical (etc.) devices

• Communication Devices
• Modems and Codecs
• LANs, Backbones and WANs
• Routers and other node devices

13
Secondary Storage Devices

• Fixed Media
• hard disks
• RAID

• Removable Media
• diskette
• laser-servo diskette
• cartridge disks
• tape
• CD-ROM
• flash memory

14
Attached Devices

• Hardware device itself such as a disk or video
  display device.
• Electronics controller that communicates with
  the device
• Software device driver that is loaded into the
  computer operating system

15
Local and Peripheral Bus
16
(No Transcript)
17
Data Transfer
MAIN MEMORY
T
A
A
D
BUFFER
CHANNEL
CPU
CPU
CPU
CPU
CPU
CONTROLLER
DASD
18
I/O Controller (DASD)
PROCESSOR
REGISTER
REGISTER
REGISTER
BUFFER
19
Direct Access Storage Device (DASD)
20
DASD Structure
Read-Write Heads
21
Cylinder/Track/Block
Block (Sector)
Track
Cylinder
22
Disk Organization
23
Data Storage

• FAT (File Access Tables), Directories and
  Catalogs
• Update and Delete
• Fragmentation and reorganization
• Blocks, Headers and Interblock Gaps

24
Hardware II
25
General Purpose Computing

• Software primacy
• Applications are controlled by changing the
  instructions run by the computer, rather than by
  changing the hardware
• ASICs and Firmware
• Any program that can be written in software can
  also be burned onto a chip as a family of circuits

26
Computer Classifications

• Size
• mainframe
• midrange
• microcomputer

• Function
• legacy mainframe
• server
• router
• client

27
Mainframe (Legacy)

• Tuned for transaction processing
• Has channels to support very large numbers of
  attached devices
• Runs a mainframe operating system
• Tend to support legacy software

28
Client/Server Architectures
FAT CLIENT
FAT SERVER
SERVER PROCESSING
CLIENT PROCESSING
CENTRALIZED
STAND-ALONE
29
Client/Server Architecture

• An architecture in which the client (personal
  computer or workstation) is the requesting
  machine and the server is the supplying machine,
  both of which are connected via a network.

30
Client/Server Architecture

• Client
• May do some or all of the processing
• Requests services from the network

• Server
• Contains data and may contain programs
• Server downloads information (applications or
  data) to the client for operation

31
Client

• Use relatively inexpensive computer chips (Intel
  or Motorola)
• Have a single processor
• Optimized for user convenience
• Single user
• Limited numbers of attached devices

32
Server

• Use inexpensive CPU chips
• Designed with redundant components
• Have large internal memory capacity
• May not need very fast CPU capability

33
Three Tier Client/Server
34
Any time Any place Any way
35
Router

• Used to segment networks and prepare message
  packets for transmission
• Special purpose operating system to read and
  forward message packets
• May support firewall functions
• Support special purpose CPU chips and optimized
  network sysems

36
Routers
From A
From B
Input Buffer
Output Buffer
Proces- sor
Input Buffer
Output Buffer
Input Buffer
Table of Addresses
To C
To D
37

• Central Architecture
• Client/Server
• Web Access