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Applications Software

- Includes various programs people use to:

• Do work

• Process data

• Play games

• Communicate with others

• Watch multimedia programs

- Unlike system and utility programs , applications software

are written y or for system users- When user orders the !" to run a particular program, the !"

transfers the program from the hard drive, diskette, or CD-

#!$ into #%$ and e&ecutes it'

- Written in a particular programming language then(compiled) or translated into machine language so the

computer can understand the commands and e&ecute the

program- !riginally, programs were written only for a speci*c

computer and could only run in that machine- +owever, due to further reserch, programs easily ecame

compatile with all computer units out in the market'

Programming Languages

- means of communicating with computer- the only language a CPU can understand is inary or

machine language- painfully tedious and virtually impossile to update and

deug- since the invention of computers, users have longed for

human like languages to manipulate computer software ut

is currently still a ig prolem ecause its very di.cult tosimply translate computer language to human language'

Generations and Levels of Programming Languages

- programming languages are divided into / generations or

sometimes into three levels'

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- (level) refers to how close the language is to the actual

machine- 0he low-level languages are machine like' !f course, it is

inary, consists strings of 1eros and ones and can e directly

understood y the computer'- +owever, it is di.cult to use and edit'

1st level

A.Machine language- 0rue language of computers- %ny program must e translated into machine language

efore the computer can e&ecute it- !nly consists of inary numers 2 and 3 representing the on

and o4 of electrical impulses- %ll data like numers, letters, and symols are represented

y cominations of inary digits' 5&ample' 0he numer 6 is

represented y eight inary numers7333333228- 0raditionally, machine languages are machine-dependent,

which means that each model of computer has its own

uni9ue machine language'B.Assembler Language

- ar more 5nglish like ut still very close to machinelanguage'

- !ne command in machine language is a single instruction to

the processor- %ssemler language instructions have a one-to-one

correspondence with a machine language instruction- %ssemler language may e a low level programming

language, it is still eing utili1ed whenever programmers

wishes to manipulate functions at the machines level

- 5&ample

C. 0hird generation ;anguages- Includes procedural languages and eginning of second level

in programming languages

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- Procedural languages re9uire the programmer to specify

oth what the computer is to do and the procedure for how

to do it'- ar more 5nglish like than assemly and machine language

- %lthough easier, still re9uires a great deal of study to learnto use these languages'

- 0he programmer must learn the words the language

recogni1es and must follow a pattern or se9uence' % single

comma or period out of place will cause the program to fail

or (crash)- "tyle and se9uence of language are called its (synta&)- !#0#%< and C!!; are e&amples of early third generation

languages

- $U$P" = 0hird generation language written speci*cally foruser in health care settings

- 7 massachussetts >eneral +ospital Utility $ulti-Programming

"ystem8- $umps was originally developed to support medical records

applications at massachusetts >eneral' $U$P" o4ers

powerful tools to support dataase management systems?

useful in cases in which several users have to access the

same dataases at the same time- $umps is now found in many industries such as anks, travel

agencies, the stock e&change, and of course other hospitals'- !riginally, mumps is oth a language and a full !"- 0oday, the most popular computer language for writing !"s

is known simply as C' named after an earlier prototype

named simply as - 0here are two important late third generation languages

which grew in importance as the use of the internet grew in

popularity'• isual Programming languages

- Programming languages facilitated program development in

graphics ased environments- @isual %"IC7eginners %ll-purpose "ymolic Instruction

Code and @isual C22'

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•  Aava

- developed y "un $icrosystems- simple program language that would provide the portaility

across di4ering computer platforms and the security needed

for use on huge, pulic network like the internet- the world community of software developers and internet

content providers has warmly received Bava'- "kills in Aava are essential for serious we developers

!. "ourth generation Languages- "peciali1ed application programs that re9uire more

involvement of the user in directing the program to do the

necessary work- 0he user speci*es what the program is to do, ut not how

the program is to perform the task' 0he how is alreadyprogrammed y the manufacturer of the language program'

- 5&ample

#. ifth >eneration ;anguages- 0hird level languages- <atural language- User tells the machine what to do in the users own natural

language or through use of a set of very 5nglish like

commands'- @oice commands are usually associated- true natural language recognition- the prolem is that it is very di.cult to translate natural

human language into inary codes which the computer

understand in order to e&ecute commands given y the user

Some Assembly Language Examples

a. MOVE 3000,4000 [4000] ← [300]  Copy contents of location 3000 tolocation 4000 b. MOVE D0,D4  [D4] ← [D0]  Copy contents of D0 to D4

c. MOVE 3000,D0  [D0] ← [3000]  Copy contents of location 3000 to

D0

d. MOVE D0,3000  [3000] ← [D0]  Copy contents of D0 to location

3000

e. MOVE #4000,D4  [D4] ← 4000  Copy the value 4000 to D4

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f MOVE #4000,5000  [50004] ← 4000  Copy the value 4000 to location

5000

g. MOVE (A0),D3  [D3] ← [[A0]]  Copy contents of location pointed

at by A0 to D3

h. MOVE #12,(A0)  [[A0]] ← 12  Copy 12 to location pointed at by

A0i. MOVE (A1),(A2)  [[A2]] ← [[A1]]  Copy contents of location pointed

at by A1 to location pointed at by A2 j. ADD D2,D1 [D1] ← [D1]+[D2]  Add contents of D1 to D2 and put

sum in D1

. ADD #13,D4 [D4] ← [D4]+12  Add 13 to D4 and put sum in D4

l. ADD (A3),1234  [1234] ← [[A3]]  Add contents of location pointed at

 by A3 to location 1234

!hat is "#$%&tands fo' ("'aphical #se' $nte'face)( and is p'onounced (gooey.( $t 'efe's to the g'aphical inte'face of a compute'

that allo*s use's to clic and d'ag objects *ith a mouse instead of ente'ing te+t at a command line. ,*o of the most popula' ope'ating systems) !indo*s and the -ac &) a'e "#$/based. ,he g'aphical use' inte'face *as fi'stint'oduced to the public by Apple *ith the -acintosh in 14. o*eve') the idea *as actually taen f'om an ea'lie'

use' inte'face developed by e'o+.