1. Computer Systems

2. COMPUTER GENERATIONS
1. VACUUM TUBES:

3. COMPUTER GENERATIONS 1. VACUUM TUBES: 1946-1959
2. TRANSISTORS:

4. COMPUTER GENERATIONS 1. VACUUM TUBES: 1946-1959
2. TRANSISTORS:
3. INTEGRATED CIRCUITS:

5. COMPUTER GENERATIONS 1. VACUUM TUBES: 1946-1959
2. TRANSISTORS:
3. INTEGRATED CIRCUITS:
4. VERY LARGE-SCALE INTEGRATED (VLSI) CIRCUITS: PRESENT *

6. SUPERCOMPUTER TERAFLOP: TRILLION CALCULATIONS/SECOND
HIGHLY SOPHISTICATED
COMPLEX COMPUTATIONS
FASTEST CPUs
LARGE SIMULATIONS
STATE-OF-THE-ART COMPONENTS
EXPENSIVE *

7. MAINFRAME LARGEST ENTERPRISE COMPUTER
MIPS: Millions of Instructions per second
LARGEST ENTERPRISE COMPUTER
5O MEGABYTES TO OVER ONE GIGABYTE RAM
COMMERCIAL, SCIENTIFIC, MILITARY APPLICATIONS
MASSIVE DATA
COMPLICATED COMPUTATIONS *

8. MINICOMPUTER MIDDLE-RANGE 10 MEGABYTES TO OVER ONE GIGABYTE RAM
UNIVERSITIES, FACTORIES, LABS
USED AS FRONT-END PROCESSOR FOR MAINFRAME *

9. MICROCOMPUTER DESKTOP OR PORTABLE
64 KILOBYTES TO OVER 128 MEGABYTES RAM
PERSONAL OR BUSINESS COMPUTERS
AFFORDABLE
MANY AVAILABLE COMPONENTS
CAN BE NETWORKED *

10. LAPTOPS & SMALLER
LAPTOP (OR NOTEBOOK): Briefcase type package, very portable, can be inexpensive, can connect to other computers or networks
HAND-HELD (OR PALMTOP): Sub-miniature, wireless computer. Growing in sophistication and connectivity *

11. BASIC COMPONENTS OF COMPUTER SYSTEMS
UNDERLYING STRUCTURE
INPUT/OUTPUT
BITS & CODING SCHEMES
ARITHMETIC LOGIC UNIT *

12. CENTRAL PROCESSING UNIT (CPU)
CONTROL UNIT
ARITHMETIC/LOGIC
UNIT
RAM
PRIMARY (MAIN) MEMORY
ROM
CLOCK

13. BUSES CPU PRIMARY STORAGE DATA BUS ADDRESS BUS CONTROL BUS OUTPUT
INPUT
DEVICES
OUTPUT
SECONDARY
STORAGE

14. 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 *

15. INPUT/OUTPUT TERMINAL POINT-OF-SALES TERMINALS
AUTOMATIC TELLER MACHINES
PUNCHED CARDS
MAGNETIC INK CHARACTER RECOGNITION (MICR): Used by banks to process checks *

16. INPUT/OUTPUT
OPTICAL CHARACTER RECOGNITION: Scanned material translated into computer characters
IMAGING: Forms, documents, photos digitized for computer use
BAR CODE LABEL: Product label information read into computer. Can be used to track inventory *

17. INPUT/OUTPUT
COMPUTER OUTPUT MICROFILM (COM): Computer rapidly generates microfilm documents for archive copies in small space
VOICE RESPONSE UNITS: Computer recognizes, generates verbal messages
MULTIMEDIA: Combines text, graphics, sound still images, animations, video *

18. HOW CHARACTERS ARE STORED IN COMPUTER MEMORY
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 *

19. EXAMPLES OF BYTES EBCDIC ASCII (assume even-parity system)
Note how sum for each byte is an EVEN number *

20. ALU & CONTROL UNIT
ARITHMETIC- LOGIC UNIT: CPU component performs logic and arithmetic operations
CONTROL UNIT: CPU component controls, coordinates other parts of computer system *

21. COMPUTER FILES
RECORD: Data about a transaction arranged in a set of FIELDS, each holding a datum
FILE: A group of similar records, such as accounts receivable or payroll
DATABASE: The files of an organization, an electronic library *

22. COMPUTER FILES
SEQUENTIAL ACCESS: A sequence of files arranged in order, say alphabetically. Usually stored on magnetic tape or cartridge
DIRECT ACCESS: Records stored on a DIRECT ACCESS STORAGE DEVICE (DASD). Can move directly to any record *

23. 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 *

24. CYLINDER 10: TRACK 10 (TOP AND BOTTOM OF EACH DISK)
DISK PACK STORAGE
LARGE SYSTEMS
RELIABLE STORAGE
LARGE AMOUNTS OF DATA
QUICK ACCESS & RETRIEVABLE
TYPICAL: 11 2-SIDED DISKS
CYLINDER: SAME TRACK ALL SURFACES
CYLINDER 10: TRACK 10 (TOP AND BOTTOM OF EACH DISK)
DISK 1
DISK 2
DISK 3
DISK 4
DISK 5
READ/WRITE
HEADS

25. THE STORED PROGRAM CONCEPT
COMPUTER IS A BINARY SYSTEM
PROGRAM: A set of instructions telling the computer what to do
INSTRUCTION: Individual step or operation in a program
MACHINE LANGUAGE: Translated instruction understood by particular model of computer *

26. CONTROLLER
LINK FOR INPUT/OUTPUT OR FILE DEVICES: To CPU and memory of large computer systems
HIGHLY SPECIALIZED PROCESSOR: Manages the operation of attached devices to free the CPU from these tasks *

27. DATA CHANNEL
SPECIALIZED INPUT/OUTPUT PROCESSOR (A COMPUTER): Takes over function of device communication from the CPU
CORRECTS FOR SPEED MISMATCH BETWEEN SLOW PERIPHERAL DEVICES AND VERY FAST CPU *

28. SYMMETRIC MULTIPROCESSOR
PROCESSORS (CPUs) ARE IDENTICAL, WITH EACH PROCESSOR OPERATING INDEPENDENTLY OF THE OTHERS
USED IN MOST MAINFRAMES AND SOME MIDRANGE MACHINES *

29. PARALLEL PROCESSOR (PP)
MULTIPLE CPUs INSTALLED AS PART OF A SINGLE COMPUTER SYSTEM: Gives separate piece of program to each of the processors so that work on the program can proceed in parallel on the separate pieces *

30. MASSIVELY PARALLEL PROCESSOR (MPP)
PARALLEL PROCESSING COMPUTER WITH MANY PARALLEL PROCESSORS:
32 OR MORE: Different CPUs capable of performing different instructions at the same time
1000 OR MORE: CPUs must all carry out the same instruction at the same time

31. Computer Software

32. THE STORED PROGRAM CONCEPT
COMPUTER IS A BINARY SYSTEM
PROGRAM: A set of instructions telling the computer what to do
INSTRUCTION: Individual step or operation in a program
MACHINE LANGUAGE: Translated instruction understood by particular model of computer *

33. EVOLUTION OF COMPUTER SOFTWARE
FIRST GENERATION: Machine language - binary language designed for particular computer
SECOND GENERATION: Assembly language - substituted mnemonic operation codes and addresses, translated to machine language by assembler *

34. EVOLUTION OF COMPUTER SOFTWARE
THIRD GENERATION: Procedural language - FORTRAN, COBOL, C - translated to machine language by compiler or interpreter. Example: COBOL
FOURTH GENERATION: Nonprocedural language. Tell what to do, not how to do it, order not important. Translate to machine language by compiler or interpreter. Example: FOCUS *

35. KEY TYPES OF SOFTWARE
APPLICATION SOFTWARE: Programs written to accomplish particular tasks for computer users
SUPPORT SOFTWARE: Programs that support application software in producing needed output. Does not directly produce output needed by users *

36. APPLICATION SOFTWARE WORD PROCESSING SPREADSHEETS
DATABASE MANAGEMENT SYSTEMS
PRESENTATION GRAPHICS *

37. APPLICATION SOFTWARE WORLD WIDE WEB BROWSERS
ELECTRONIC MAIL, GROUPWARE
DESKTOP PUBLISHING
APPLICATION SUITES *

38. SUPPORT SOFTWARE
OPERATING SYSTEMS: Helps maximize work done, eases workload of users
JOB CONTROL LANGUAGE: Allows users to communicate with operating systems
MULTIPROGRAMMING: Large computers can run multiple programs simultaneously. Time-driven approach is time-sharing *

39. SUPPORT SOFTWARE
MULTITASKING: Allows small computers to work on several programs interactively
VIRTUAL MEMORY: Allows computer to run portions of a large program as required, saving use of main memory
MULTIPROCESSING: Multiple CPUs divide workload, increases efficiency *

40. SOURCES OF OPERATING SYSTEMS
PROPRIETARY: Written for particular computer class or system. Examples: Windows 98, Windows 2000
OPEN SYSTEM: Not tied to specific platform. Examples: UNIX, Linux
NETWORK OPERATING SYSTEM (NOS): Manages network resources, local area networks *

41. GRAPHICAL USER INTERFACE (GUI)
MOUSE: A standard pointing device
ICON: Graphic or label on screen associated with task or operation
32-BIT OPERATING SYSTEM: Operating system handles 32 bits at a time
CLICKING MOUSE ON ICON INITIATES TASK *

42. OBJECT-ORIENTED PROGRAMMING (OOP)
COMPUTER PROGRAMMING BASED ON CREATING, USING SET OF OBJECTS: Object combines data and methods (or chunks of programs)
EXAMPLES: C++, Smalltalk, Java *

43. OTHER LANGUAGES
NATURAL LANGUAGES: User types in or speaks English, computer evolves program
HYPERTEXT MARKUP LANGUAGE (HTML): Code used to develop World Wide Web (WWW) pages and sites
eXtensible Markup Language (XML): Used for data exchange on WWW *

44. DATABASE MANAGEMENT SYSTEM (DBMS)
SUPPORT SOFTWARE USED TO CREATE, MANAGE, AND PROTECT ORGANIZATIONAL DATA
DBMS: Software that manages a database, works with operating system to store and modify data and to make data accessible in authorized ways *

45. TYPES OF DBMSs
HIERARCHICAL: Data arranged in a top-down, organization chart fashion
NETWORK: Data arranged like cities on a highway systems, often with multiple paths between pieces of data
RELATIONAL: Data arranged into simple tables, and records are related by storing common data in each of the associated tables *

46. FILING METHODS INDEXED SEQUENTIAL ACCESS METHOD (ISAM) :
EACH RECORD IDENTIFIED BY KEY
GROUPED IN BLOCKS AND CYLINDERS
KEYS IN INDEX
VIRTUAL STORAGE ACCESS METHOD (VSAM) :
MEMORY DIVIDED INTO AREAS & INTERVALS
DYNAMIC FILE SPACE
VSAM WIDELY USED FOR RELATIONAL DATABASES
DIRECT FILE ACCESS METHOD *

47. COMPONENTS OF DBMS:
DATA DEFINITION LANGUAGE: Defines data elements in database
DATA MANIPULATION LANGUAGE: Manipulates data for applications
DATA DICTIONARY/DIRECTORY: Formal definitions of all variables in database, controls variety of database contents *

48. STRUCTURED QUERY LANGUAGE (SQL)
EMERGING STANDARD
DATA MANIPULATION LANGUAGE
FOR RELATIONAL DATABASES *

49. ADVANTAGES OF RELATIONAL DBMS
NEW DATA ELEMENTS CAN EASILY BE ADDED AS NEW NEEDS ARISE
NEW RELATIONSHIPS CAN BE CREATED AS NEW QUERY/REPORTING NEEDS CHANGE
FEWER DATA CONSISTENCY PROBLEMS DUE TO LESS REDUNDANT DATA STORAGE
MORE “USER FRIENDLY” TOOLS *

50. COMPUTER-AIDED SOFTWARE ENGINEERING (CASE)
HELPS AUTOMATE SOFTWARE DEVELOPMENT: Used by computer professionals to help automate software development
MAY INCLUDE:
upper-CASE (requirements definition and design)
lower-CASE (code generation)
I-CASE or integrated-CASE *

51. CHANGING NATURE OF SOFTWARE
MORE HARDWIRING OF SOFTWARE AND MORE MICROCODE
MORE COMPLEXITY OF HARDWARE/SOFTWARE ARRANGEMENTS
LESS CONCERN WITH MACHINE EFFICIENCY *

52. CHANGING NATURE OF SOFTWARE
MORE PURCHASED APPLICATIONS AND MORE PORTABILITY OF THESE APPLICATIONS FROM ONE COMPUTER PLATFORM TO ANOTHER
MORE PROGRAMMING USING OBJECT-ORIENTED AND VISUAL LANGUAGES, IN LARGE PART BECAUSE OF EMPHASIS ON GUIs *

53. CHANGING NATURE OF SOFTWARE
MORE EMPHASIS ON APPLICATIONS THAT RUN ON INTRANETS AND THE INTERNET
MORE USER DEVELOPMENT
MORE USE OF PERSONAL PRODUCTIVITY SOFTWARE ON MICROCOMPUTERS, ESPECIALLY PACKAGES WITH A GUI *