E. Wainright Martin Carol V. Brown Daniel W. DeHayes Jeffrey A. Hoffer William C. Perkins MANAGINGINFORMATIONTECHNOLOGY FIFTH EDITION CHAPTER 2 C OMPUTER S YSTEMS

© 2005 Pearson Prentice-Hall Chapter Vacuum tubes First Generation of Computers E VOLUTION OF C OMPUTER S YSTEMS Page 24

© 2005 Pearson Prentice-Hall Chapter Vacuum tubes 2.Transistors Second Generation of Computers Page 24 E VOLUTION OF C OMPUTER S YSTEMS

© 2005 Pearson Prentice-Hall Chapter Vacuum tubes 2.Transistors 3.Integrated circuits Third Generation of Computers Page 25 E VOLUTION OF C OMPUTER S YSTEMS

© 2005 Pearson Prentice-Hall Chapter present Vacuum tubes 2.Transistors 3.Integrated circuits 4.VLSI (very-large-scale integrated) circuits Fourth Generation of Computers Page 25 E VOLUTION OF C OMPUTER S YSTEMS

© 2005 Pearson Prentice-Hall Chapter present The Development of Minicomputers Page 26 E VOLUTION OF C OMPUTER S YSTEMS DEC Hewlett-Packard IBM Data General

© 2005 Pearson Prentice-Hall Chapter present The Development of Microcomputers Page 26 E VOLUTION OF C OMPUTER S YSTEMS Apple IBM PC 1981

© 2005 Pearson Prentice-Hall Chapter Page 26 B ASIC C OMPONENTS OF C OMPUTER S YSTEMS

© 2005 Pearson Prentice-Hall Chapter Page Table 2.1 Evolution of Intel Microprocessor

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Underlying Structure Figure 2.4 Logical Structure of Digital Computers Page 28

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Input/Output

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Input/Output Page 28 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

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Input/Output Terminal  Special types: Point-of-sale (retail) ATMs (banking) Page 28

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS 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 Page 29

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS 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 Page 29

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Input/Output Page 29 Multimedia – relatively new term for computer input and output in the form of text, graphics, sound, still images, animations, and/or video Of interest …

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Computer Memory

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Computer Memory Page 31 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

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Bits and Coding Schemes Page 32 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

© 2005 Pearson Prentice-Hall Chapter Bits and Coding Schemes Page 32 Figure 2.4 Computer Coding Schemes

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Arithmetic/Logical Unit

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Consists of VLSI circuits on a silicon chip Carries out:  arithmetic – add, subtract, multiply, divide …  logical operations – comparing two numbers Arithmetic/Logical Unit Page 33

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Computer Files

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS 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 Computer Files Page 33

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Sequential access files  Usually stored on magnetic tape drives Direct access files  Stored on Direct Access Storage Devices (DASD) - magnetic disk drives Computer Files Page 34

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Types of DASD  Fixed (hard) drives Computer Files Page 34 Figure 2.7 Diagram of a Magnetic Disk Drive

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Types of DASD  Removable: Floppy drives Zip drives Newest: portable DASD for PCs – keychain drive Computer Files Figure 2.8 Iomega’s Mini USB Keychain Drive Page 34

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Newer type of DASD  Optical Disk Storage CD-ROM700 megabytesread-only CD-Rrecordable CD-RWrewritable DVD-ROM4.7 gigabytesread-only DVD-Rrecordable DVD-RW rewritable Computer Files Page 36

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Control Unit

© 2005 Pearson Prentice-Hall Chapter B ASIC C OMPONENTS OF C OMPUTER S YSTEMS Control Unit Page 36 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

© 2005 Pearson Prentice-Hall Chapter T HE S TORED- P ROGRAM C ONCEPT Page 37 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

© 2005 Pearson Prentice-Hall Chapter T HE S TORED- P ROGRAM C ONCEPT Page 38 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

© 2005 Pearson Prentice-Hall Chapter Page 39 Table 2.2 Benchmarking Top Seven Desktop PCs – Power System T HE S TORED- P ROGRAM C ONCEPT

© 2005 Pearson Prentice-Hall Chapter Page 40 Figure 2.9 Data Channels and Controllers E XTENSIONS TO THE B ASIC M ODEL Communications within the Computer System Terminals Magnetic Tape Units Magnetic Disk Units

© 2005 Pearson Prentice-Hall Chapter Page 40 Figure 2.10 Cache Memory E XTENSIONS TO THE B ASIC M ODEL 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

© 2005 Pearson Prentice-Hall Chapter Page E XTENSIONS TO THE B ASIC M ODEL Multiple Processor Configurations Multiprocessor Symmetric multiprocessor (SMP) Vector facility Parallel processor (PP) Massively parallel processor (MPP)

© 2005 Pearson Prentice-Hall Chapter Page T YPES OF C OMPUTER S YSTEMS Microcomputers Cost in $ MFLOPSMajor VendorsPrimary Uses 200-3, IBM, Dell, Hewlett-Packard, Gateway, Fujitsu, Toshiba Personal computing Client in client/server applications Web client Small business processing

© 2005 Pearson Prentice-Hall Chapter Page Workstation/Midrange Systems Cost in $ MFLOPSMajor VendorsPrimary Uses 3,000-1,000, ,000IBM, 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 T YPES OF C OMPUTER S YSTEMS

© 2005 Pearson Prentice-Hall Chapter Page Mainframe Computers Cost in $ MFLOPSMajor VendorsPrimary Uses 1,000, ,000, ,000 IBM, Fujitsu, Groupe Bull, Unisys Large business general processing Server in client/server applications Large Web server Widest range of applications T YPES OF C OMPUTER S YSTEMS

© 2005 Pearson Prentice-Hall Chapter Page 49 Supercomputers Cost in $ MFLOPSMajor VendorsPrimary Uses 1,000, ,000,000 4, ,000,000 IBM, Hewlett- Packard, Dell, Hitachi, Cray, NEC Numerically intensive scientific calculations Very large Web server T YPES OF C OMPUTER S YSTEMS