1. What is software? Processor needs instructions that tell it what to do
these instructions are called software
When NOT in use, almost all software stored on mass storage devices (e.g., a floppy or hard disk) How does it get there?
When IN use, software stored in processor’s memory (in RAM) 39 19 19

2. Software is costly
Businesses typically spend more on software than on hardware
This trend is too easy to miss

3. SOFTWARE DETAILED INSTRUCTIONS TO CONTROL COMPUTER OPERATION
PROGRAM: SET OF INSTRUCTIONS TO THE COMPUTER
STORED: PROGRAM MUST BE IN PRIMARY STORAGE
SYSTEM SOFTWARE: MANAGES COMPUTER RESOURCES
APPLICATION SOFTWARE: SPECIFIC BUSINESS APPLICATION *

4. SOFTWARE OPERATING SYSTEM:
APPLICATION SOFTWARE
OPERATING SYSTEM:
SCHEDULED COMPUTER EVENTS ALLOCATES COMPUTER RESOURCES MONITORS EVENTS
LANGUAGE TRANSLATORS:
INTERPRETERS COMPILERS
UTILITY PROGRAMS:
ROUTINE OPERATIONS MANAGE DATA
SYSTEM SOFTWARE
HARDWARE

5. SOFTWARE OPERATING SYSTEM:
APPLICATION SOFTWARE
OPERATING SYSTEM:
SCHEDULED COMPUTER EVENTS ALLOCATES COMPUTER RESOURCES MONITORS EVENTS
LANGUAGE TRANSLATORS:
INTERPRETERS COMPILERS
UTILITY PROGRAMS:
ROUTINE OPERATIONS MANAGE DATA
SYSTEM SOFTWARE
HARDWARE
PROGRAMMING LANGUAGES:
ASSEMBLY LANGUAGE; FORTRAN; COBOL; PL / 1; QBASIC; PASCAL; C; C++; “FOURTH GENERATION” LANGUAGES

6. HTML is not a programming language, neither is XML

7. A play: Scene 1 ? ! 9

8. What’s on that disk? …
p := x + y;
write(‘dfile.dat’, p);
... 10 10

9. Scene 2 : Act 1 … p := x + y; write(‘dfile.dat’, p); ... Machine
instructions
Compiler 11

11. Compilers vs. interpreters
translates the whole program into machine language at one time
will run faster
Interpreter
translates and executes the program one statement at a time
generally easier and faster program development
may be easier to debug 13

12. Scene 2 : Act 2
Saved to
Machine
instructions 13

13. Scene 2 : Act 3
Use the
program 14

14. Scene 3
Machine
instructions
Copied
to RAM
Begins to
execute 15

15. Programming Languages
Specialized
Fortran - Science & Engineering (1957)
LISP - Artificial Intelligence (1958)
COBOL - Business (1959)
Generalized
PL/I - developed by IBM (1964)
C - developed by AT&T (1972)
Teaching 10

16. Generations of programming languages
Machine language (1st)
Assembler language (2nd)
High-level languages (3rd)
Ada, BASIC, C, C++, COBOL, FORTRAN, LISP, Pascal, PL/1, etc.
Java, Visual BASIC, C#, etc.
Fourth- and fifth-generation
SQL, Prolog, query languages, etc. 11

18. GENERATIONS OF PROGRAMMING LANGUAGES
1st. Since 1940s. MACHINE LANGUAGE: binary code
2nd. Since early ’50s. ASSEMBLY LANGUAGE: mnemonics for numeric code
3rd. Since mid ‘50s. HIGH-LEVEL LANGUAGES
4th. Since late ‘70s. MODERN APPLICATION PACKAGES *

19. Which level is for me? Lower level Higher level
more control over how program works
can be more efficient
Higher level
easier and faster to develop and debug programs
Clear trend to higher levels (3 or up) 12

21. FOURTH GENERATION LANGUAGES (4GL)
CAN BE EMPLOYED BY END USERS
NONPROCEDURAL
CAN DEVELOP APPLICATIONS QUICKLY
NATURAL LANGUAGES
SIX CATEGORIES *

22. FOURTH GENERATION LANGUAGES (4GL)
1. QUERY LANGUAGES:
RAPIDLY RETRIEVE DATA
INTERACTIVE
ON-LINE
SUPPORT SPECIAL REQUESTS FOR DATA FROM RELATIONAL DATABASES *

23. FOURTH GENERATION LANGUAGES (4GL)
2. REPORT GENERATORS:
CREATE CUSTOMIZED REPORTS
WIDE RANGE OF FORMATS
3. GRAPHICS LANGUAGES:
CAN MANIPULATE DRAWINGS, GRAPHS, PHOTOS, VIDEOS
PRESENTATION MANAGERS *

24. FOURTH GENERATION LANGUAGES (4GL)
4. APPLICATION GENERATORS:
USER SPECIFIES COMPUTER NEEDS
GENERATOR CREATES LOGIC AND CODE FOR APPLICATION
GREATLY REDUCES DEVELOPMENT TIME *

25. FOURTH GENERATION LANGUAGES (4GL)
5. VERY HIGH-LEVEL PROGRAMMING LANGUAGES:
PROFESSIONAL PROGRAMMER PRODUCTIVITY TOOL
USES FEWER INSTRUCTIONS
REDUCES DEVELOPMENT TIME *

26. FOURTH GENERATION LANGUAGES (4GL)
6. SOFTWARE PACKAGE: COMMERCIALLY AVAILABLE SET OF PROGRAMS...
WORD PROCESSING
SPREADSHEETS
DATA MANAGEMENT
PRESENTATION MANAGEMENT
INTEGRATED SOFTWARE PACKAGES NOW COMBINE THESE TO SIMPLIFY LEARNING AND USE *

27. Types of software Applications software Systems software
satisfies specific user need
Systems software
Operating system
makes hardware more usable
Language translators
translates human readable to machine language
Utilities 40 20 20

28. Operating system functions (1/2)
Manage resources
memory
implement “virtual memory” which allows a computer to pretend that it has more memory than it actually does (see next slide) 41 21 21

30. Example: Memory management
Heavy line–actual RAM, thin–perceived memory, dotted–one program
Single space Partitions Virtual memory
Task 1
Task 1
Task 4
Task 5
Task 2
Task 2
Task 1
Task 6
Task 3
Task 3
Task 7 42 22 22

31. Operating system functions (2/2)
Coordinator for application programs
Manage resources
memory
devices
Coordinate activities
Manage files
User interface (GUI) 43 23 23

32. Why do operating systems matter?
They provide different features
e.g., memory management, GUI
Programs are written for an O/S
choose applications, then choose O/S
O/S used to be proprietary
choice of O/S dictated choice of hardware 46 25 25

33. Trends in operating systems
Multi-programming
Multi-processing
Virtual memory
Interprocess communications
More features
new kinds of I/O supported
better integration of programs
Require more powerful hardware
Cathedrals vs. Bazaars… 47 26 26

34. Types of user interfaces
Command-oriented interfaces
prompt the user to type in a command that is translated into an instruction for the program to follow
Menu-driven interfaces
offer a list of choices or options, called a menu, as a way of letting a user choose from several different commands or functions
Graphical User Interfaces (GUI’s)
use pictures and graphic symbols to represent commands, choices or actions
Natural Language interfaces
allow the user to input simple English statements that are translated into commands by the program. 45 24 24

35. Object Linking & Embedding
Object Linking & Embedding (OLE) allows user to copy text/graphics from one document to another or to embed text/graphics from one program into another program/document
Server Application supplies objects user places in other applications
Client application accepts objects from other applications
Copy copies data from one application & places it in another
Link is used when user wants changes made to the server object to appear automatically in all linked client objects
Embed is used when user wants an object to become part of the client document

36. OBJECT-ORIENTED PROGRAMMING
COMBINES DATA & PROCEDURES INTO A SINGLE OBJECT
PROGRAM SENDS MESSAGE TO OBJECT TO PERFORM EMBEDDED PROCEDURE
OBJECT’S DATA ENCAPSULATED FROM REST OF SYSTEM
CREATES REUSABLE CODE
REDUCES TIME AND COST OF WRITING SOFTWARE *

37. OBJECT-ORIENTED PROGRAMMING
VISUAL PROGRAMMING: SELECT AND ARRANGE OBJECTS RATHER THAN WRITE CODE
CLASS: ALL OBJECTS OF A CLASS HAVE ALL FEATURES OF THAT CLASS
INHERITANCE: SPECIFIC CLASS RECEIVES FEATURES OF A MORE GENERAL CLASS
OVERRIDE: SUBCLASS MAY OVEERRIDE INHERITED METHOD (e.g.: Printout of an HOURLY worker Pay Check may differ from that of a WEEKLY worker *

38. OBJECT-ORIENTED PROGRAMMING
JAVA: Sun Microsystems OBJECT-ORIENTED PROGRAMMING LANGUAGE
APPLET: TINY PROGRAM TO EXECUTE SMALL FUNCTION
APPLETS DOWNLOADED FROM NETWORK
RUN ON ANY COMPUTER & OPERATING SYSTEM
RESULT SAVED ON NETWORK, NOT ON PC
ONLY NETWORK VERSION OF SOFTWARE NEEDS UPGRADE *

39. JAVA Write Once Run Anywhere (!?) Object Oriented Programming Language
Using applets allows:
elimination of need for large & expensive hardware
elimination of lots of storage and maintenance overhead

40. JAVA (what we will still see...)
It IS neither entirely compiled nor entirely interpreted (BYTECODE)
It IS comparatively easy to learn
It IS capturing everyone’s attention
Will it be (a) standard?
Will it be secure?
Will it be fast enough?
WHAT ABOUT C#?

41. .NET (dot Net)
.NET is Microsoft's next-generation Visual Studio development environment, yet another new programming language (C#), and a new data-exchange and messaging framework, based on XML and SOAP.
While java promises platform portability, .NET promises language portability.

42. Multi-programming, tasking…
Multiprogramming: groups of programs take turns
Multitasking: single user, numerous uses
Time sharing: fixed-time multiprogramming
Multiprocessing: parallel, multiple processors.

44. TRADITIONAL SINGLE-PROGRAM SYSTEM
MULTIPROGRAMMING
TRADITIONAL SINGLE-PROGRAM SYSTEM
OPERATING SYSTEM
UNUSED MEMORY
PROGRAM 1

45. TRADITIONAL SINGLE-PROGRAM SYSTEM MULTIPROGRAMMING ENVIRONMENT
OPERATING SYSTEM
UNUSED MEMORY
OPERATING SYSTEM
UNUSED MEMORY
PROGRAM 1
PROGRAM 2
PROGRAM 1
PROGRAM 3

46. MULTITASKING MULTIPROGRAMMING ON A SINGLE-USER SYSTEM SUCH AS A
MICROCOMPUTER *

47. VIRTUAL STORAGE
METHOD OF HANDLING SEVERAL PROGRAMS IN PRIMARY STORAGE:
PROGRAM DIVIDED INTO
FIXED LENGTH PORTIONS (PAGES) OR
VARIABLE LENGTH (SEGMENTS)
CURRENT PORTIONS RESIDE IN PRIMARY STORAGE
PORTIONS SWAPPED OUT WHEN DONE *

48. TIME SHARING MANY USERS SHARE LARGE CPU:
TIME IN CPU DIVIDED INTO SLICES (e.g.: 2 MILLISECONDS)
EACH USER HAS ACCESS TO CPU DURING SLICE
SINCE CPU IS FAST, CAN DO MUCH DURING TIME SLICE
USER’S JOB SWAPPED OUT AT END OF SLICE *

49. MULTIPROCESSING TWO OR MORE PARALLEL PROCESSORS IN SYSTEM
PROGRAM CAN BE DIVIDED TO BE PROCESSED BY MULTIPLE CPUs
CAN PROCESS LARGE PROGRAMS MORE RAPIDLY *

50. Applications

51. Groupware

52. ASP – application service providers

53. Web Services
A group of closely related, emerging technologies that describe a service-oriented, component-based application architecture that is based on an open, Internet-centric infrastructure. Web services represent a model in which discrete tasks within e-business processes are distributed widely throughout a value net.
Not a specific technology, but rather a group of established and emerging communication protocols that include HTTP, XML, Simple Object Application Protocol (SOAP), Universal Description Discovery and Integration (UDDI), and Web Services Description Language (WSDL). A web service can be developed on any computer platform and in any development environment, as long as it can communicate with other web services using these common protocols.

54. The Generic Web Service Architecture
Web Services
The Generic Web Service Architecture

55. Web Services
Although ASPs and web services both implement the concept of "software as a service," the similarities end there. ASPs deliver entire applications from a central hosting location, while web services are distributed components. ASPs form a closed "black box," while web services are inherently extensible. ASPs are as much business model as technology solution; web services may enable new forms of business models, but are fundamentally a technology solution.
IBM and Microsoft have taken the early leadership mantle in establishing the web services stack. Hewlett-Packard, an early proponent of a proprietary services model, now is reorienting towards web services (NetAction). Oracle, Sun (ONE), and a host of smaller companies (e.g. BEA, Bowstreet, and others) have also put hats into the ring.

56. Summary Many features of a computer determine how fast it actually is
Computers are very fast and are getting faster for the foreseeable future
An operating system can make it easier to create more powerful and easy-to-use programs 49 27 27