1. CHAPTER 2 COMPUTER SYSTEMS

2. EVOLUTION OF COMPUTER SYSTEMS
First Generation of Computers
Vacuum tubes
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3. EVOLUTION OF COMPUTER SYSTEMS
Second Generation of Computers
Vacuum tubes
Transistors
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4. EVOLUTION OF COMPUTER SYSTEMS
Third Generation of Computers
Vacuum tubes
Transistors
Integrated circuits
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5. EVOLUTION OF COMPUTER SYSTEMS
Fourth Generation of Computers
Vacuum tubes
Transistors
Integrated circuits
VLSI (very-large-scale integrated) circuits
present
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6. EVOLUTION OF COMPUTER SYSTEMS
The Development of Minicomputers
Data General
DEC
Hewlett-Packard
IBM
present
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7. EVOLUTION OF COMPUTER SYSTEMS
The Development of Microcomputers
Apple
IBM PC
1981
present
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8. BASIC COMPONENTS OF COMPUTER SYSTEMS
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9. Page 26-27 Table 2.1 Evolution of Intel Microprocessor
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Table 2.1 Evolution of Intel Microprocessor
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10. BASIC COMPONENTS OF COMPUTER SYSTEMS
Underlying Structure
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Figure 2.4 Logical Structure of Digital Computers
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11. BASIC COMPONENTS OF COMPUTER SYSTEMS
Input/Output
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12. BASIC COMPONENTS OF COMPUTER SYSTEMS
Input/Output
Terminal
Simpler than a PC
Designed strictly for input and output
Has keyboard and screen
Does not have a processor
Connected to computer with telecommunication line
Allows user to key data directly into computer
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13. BASIC COMPONENTS OF COMPUTER SYSTEMS
Input/Output
Terminal
Special types:
Point-of-sale (retail)
ATMs (banking)
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14. BASIC COMPONENTS OF COMPUTER SYSTEMS
Input/Output
Common input methods:
Magnetic ink character recognition (MICR) – used to process bank checks
Optical character recognition (OCR) – directly scans typed, printed, or handwritten material
Imaging – inputs digital form of documents and photos
Bar code labeling – scans bar codes on packages or products, and reads into computer
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15. BASIC COMPONENTS OF COMPUTER SYSTEMS
Input/Output
Common output methods:
Print – output to paper using various types of printers
Computer output microfilm (COM) – microfilm generated for archive copies in small space
Voice response units – computer recognizes input, generates verbal response messages
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16. BASIC COMPONENTS OF COMPUTER SYSTEMS
Input/Output
Of interest …
Multimedia –
relatively new term for computer input and output in the form of text, graphics, sound, still images, animations, and/or video
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17. BASIC COMPONENTS OF COMPUTER SYSTEMS
Computer Memory
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18. BASIC COMPONENTS OF COMPUTER SYSTEMS
Computer Memory
Memory
All data flows to and from memory
Divided into cells:
Each has a unique address
Memory cell types:
Byte – stores one character of data
Word – stores two or more characters of data
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19. BASIC COMPONENTS OF COMPUTER SYSTEMS
Bits and Coding Schemes
Each memory cell is a set of circuits
Each circuit is on or off (represented by 1 or 0)
Each circuit corresponds to a bit (binary digit)
Most computers – 8 bits (circuits) represents a character (byte)
2 common bit coding schemes used today:
ASCII
EBCDIC
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20. Bits and Coding Schemes. . . . . .
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Figure Computer Coding Schemes
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21. BASIC COMPONENTS OF COMPUTER SYSTEMS
Arithmetic/Logical Unit
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22. BASIC COMPONENTS OF COMPUTER SYSTEMS
Arithmetic/Logical Unit
Consists of VLSI circuits on a silicon chip
Carries out:
arithmetic – add, subtract, multiply, divide …
logical operations – comparing two numbers
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23. BASIC COMPONENTS OF COMPUTER SYSTEMS
Computer Files
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24. BASIC COMPONENTS OF COMPUTER SYSTEMS
Computer Files
When power is off, everything stored in memory is lost
Computer files are used to store data long term
File storage devices:
Magnetic tape drives, disk drives, floppy drives
Optical CD or DVD drives
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25. BASIC COMPONENTS OF COMPUTER SYSTEMS
Computer Files
Sequential access files
Usually stored on magnetic tape drives
Direct access files
Stored on Direct Access Storage Devices (DASD) - magnetic disk drives
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26. BASIC COMPONENTS OF COMPUTER SYSTEMS
Computer Files
Types of DASD
Fixed (hard) drives
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Figure Diagram of a Magnetic Disk Drive
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27. BASIC COMPONENTS OF COMPUTER SYSTEMS
Computer Files
Types of DASD
Removable:
Floppy drives
Zip drives
Newest: portable DASD for PCs – keychain drive
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Figure Iomega’s Mini USB Keychain Drive
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28. BASIC COMPONENTS OF COMPUTER SYSTEMS
Computer Files
Newer type of DASD
Optical Disk Storage
CD-ROM 700 megabytes read-only
CD-R recordable
CD-RW rewritable
DVD-ROM 4.7 gigabytes read-only
DVD-R recordable
DVD-RW rewritable
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29. BASIC COMPONENTS OF COMPUTER SYSTEMS
Control Unit
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30. BASIC COMPONENTS OF COMPUTER SYSTEMS
Control Unit
Controls computer to take advantage of speed and capacity of other components
Directed by list of operations (program) that tells control unit what to do
Uses the stored-program concept
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31. THE STORED-PROGRAM CONCEPT
Program – list of what computer needs to do for an application
Instruction – each individual step or operation in a program
Control unit – carries out one step or instruction at a time at electronic speed
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32. THE STORED-PROGRAM CONCEPT
Note: One of the primary measures of power of computers is the number of instructions it can execute in a given period
MIPS – millions of instructions per second executed by the control unit
MFLOPS – millions of floating point operations per second
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33. THE STORED-PROGRAM CONCEPT
Top Seven Desktop PCs – Power System
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Table Benchmarking
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34. EXTENSIONS TO THE BASIC MODEL
Communications within
the Computer System
Terminals
Magnetic
Tape Units
Magnetic
Disk Units
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Figure Data Channels and Controllers
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35. EXTENSIONS TO THE BASIC MODEL
Cache Memory
High-speed storage to temporarily hold data from main memory waiting to be processed
Entire blocks of data moved at one time into cache
Enables CPU to execute much faster
Also incorporated into DASD controllers
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Figure Cache Memory
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36. EXTENSIONS TO THE BASIC MODEL
Multiple Processor Configurations
Multiprocessor
Symmetric multiprocessor (SMP)
Vector facility
Parallel processor (PP)
Massively parallel processor (MPP)
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37. TYPES OF COMPUTER SYSTEMS
Microcomputers
Cost in $
MFLOPS
Major Vendors
Primary Uses
200-3,000
20-400
IBM, Dell, Hewlett-Packard, Gateway, Fujitsu, Toshiba
Personal computing
Client in client/server applications
Web client
Small business processing
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38. TYPES OF COMPUTER SYSTEMS
Workstation/Midrange Systems
Cost in $
MFLOPS
Major Vendors
Primary Uses
3,000-1,000,000
40-4,000
IBM, Dell, Hewlett-Packard, Gateway, NEC, NCR, Fujitsu, Toshiba, Sun Microsystems
Departmental computing
Specific applications (office automation, CAD, other graphics)
Midsized business general processing
Server in client/server applications
Web server, file server, LAN server
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39. TYPES OF COMPUTER SYSTEMS
Mainframe Computers
Cost in $
MFLOPS
Major Vendors
Primary Uses
1,000, ,000,000
200 -8,000
IBM, Fujitsu, Groupe Bull, Unisys
Large business general processing
Server in client/server applications
Large Web server
Widest range of applications
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40. TYPES OF COMPUTER SYSTEMS
Supercomputers
Cost in $
MFLOPS
Major Vendors
Primary Uses
1,000, ,000,000
4, ,000,000
IBM, Hewlett-Packard, Dell, Hitachi, Cray, NEC
Numerically intensive scientific calculations
Very large Web server
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