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The Language of COBOL . Abby Jamgochian Brittani Hans. Purpose of Development. Federal Gov. needed program source language for business personnel All current programs at the time math nature Currently facing expense reprogramming chargers Each computer needed new install program.
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The Language of COBOL Abby Jamgochian Brittani Hans
Purpose of Development • Federal Gov. needed program source language for business personnel • All current programs at the time math nature • Currently facing expense reprogramming chargers • Each computer needed new install program
THE BIRTH • Grace Murray Hopper designer • April 1960 • Presented by COnference on DAta Systems Language (CODASYL) • Members computer professionals including: • US Gov. • Manufacturers of computer equipment • Universities • Active users
Developing • Original Proposal • Machine independent • Ability to constantly change • Similar format of English statements • Free of math and scientific symbols • Businessman Friendly • No experience necessary
Growing…Growing…GROWING • Through the years • Three different versions of COBOL • ANSI 1968 COBOL • The standards developed • ANSI 1974 COBOL • Updated ANSI standards • Ability to use ‘68 or ’74 • ANSI 1985 COBOL • Expected many companies • ‘the future’
COBOL is the “IN” Crowd • Why so Popular? • Meets the needs of users • Language translator supported by user • Meant to decrease future cost • Included in more software packages than any other • MACHINE-INDEPENDENT • Not plagued by computer obsolescence (Always being revised to meet new computer needs) • English readability and looking business like
ADVANTAGES • Communication advancement • Pretested input/output modules included • Language familiar if so fact oh less killer robot murders • Easily converted one machine to another • Can be broken down into other smaller group jobs • Its logical • Debugging time decreased b/c list is generated of errors (NOT LOGIC ERRORS)
……Disadvantages • Permanent solutions without reprogramming • Assuming COBOL is the only language needed…no other computer knowledge • Need a large storage memory • Will not generate as sophisticated then assembly language • Wordy
Program Organization • Identification • tells program to computer • info needed to identify written and compiled sources • Name program, author, what program does ect. • Environment • describes use & hardware needed • Machine-independent • Particular computer used and associated input/output
Program Organization • Data • define chars, files, layouts & storage location • Formats chars for input/output to process • Procedure • Solve a given problem • Actions expected to process data
ABSTRACTION!!!!! Data Types: • Numeric • Alphanumeric aka. Strings/text • Alphabetic aka…A,B,C,D Data Types Declared: • Level number • Data-name/identifier • Picture clause
Controlling ABSTRACTION!!!!! • < > < = >= = NOT= • And • Not • Or • Else clause, nest selection, while statement, for statement
The Yellow Subbbbb…. Programs • Linked Program • Executable object module • Dynamically loaded • Intermediate code files • Generate Code File • Callable share Object
Coding. 000100 IDENTIFICATION DIVISION. 000200 PROGRAM-ID. HELLOWORLD. 000300 000400* 000500 ENVIRONMENT DIVISION. 000600 CONFIGURATION SECTION. 000700 SOURCE-COMPUTER. RM-COBOL. 000800 OBJECT-COMPUTER. RM-COBOL. 000900 001000 DATA DIVISION. 001100 FILE SECTION. 001200 100000 PROCEDURE DIVISION. 100100 100200 MAIN-LOGIC SECTION. 100300 BEGIN. 100400 DISPLAY " " LINE 1 POSITION 1 ERASE EOS. 100500 DISPLAY "Hello world!" LINE 15 POSITION 10. 100600 STOP RUN. 100700 MAIN-LOGIC-EXIT. 100800 EXIT.
Display output… Hello World
Sources http://www.csee.umbc.edu/courses/graduate/631/Fall2002/COBOL.pdf www.pgrocer.net/Cis12/cobollan.htmlcobolforgcc.sourceforge.net/cobol_2.html groups.engin.umd.umich.edu/CIS/course.des/cis400/cobol/cobol.html inventors.about.com/od/hstartinventors/a/Grace_Hopper.html www.math-cs.gordon.edu/course/cs323/COBOL/cobol.html datamuseum.dk/site_dk/rc/pbh/siemenscobol.pdf www.csee.umbc.edu/courses/graduate/631/Fall2002/COBOL.pdf homepages.paradise.net.nz/milhous/cobol.htm