1. Presented by: Destry Diefenbach
FORTRAN 77
Presented by:
Destry Diefenbach

2. The Free Online Dictionary of Computing (http://foldoc.doc.ic.ac.uk/)
Fortrash
<abuse, language> /for'trash/ Hackerism for the Fortran language, referring to its primitive design, gross and irregular syntax, limited control constructs, and slippery, exception-filled semantics.
[Jargon File]
( )

3. “Algol is FORTRAN done right.” -Bruce Knobe, 1973
“Pascal is FORTRAN done right.” -Raymond Langsford, 1980
“FORTRAN 77 is FORTRAN done right.” -James Ball, 1983

4. History of FORTRAN John Backus
Stands for IBM Mathematical FORmula TRANslation System but abbreviated to FORmula TRANslation
FORTRAN 0 was developed by a IBM research team headed by John Backus in 1954.
Was the first high-level programming language
John Backus

5. More History
The design of FORTRAN made it easier to translate mathematical formulas into code.
FORTRAN originally began as a digital code interpreter for the IBM 701
At that time it was called Speedcoding
The point of FORTRAN was to make programming easier.
IBM 701

6. FORTRAN I 1957 Was the first compiler
By 1958 over 50% of software was in FORTRAN
Cut development time.
2 weeks to 2 hours

7. FORTRAN II - IV FORTRAN II FORTRAN III FORTRAN IV
Independent compilation
Fix the bugs
FORTRAN III
Was developed, but it was never widely distrbuted
FORTRAN IV
Explicit type declarations
Logical selection (IF) statement
Subprogram names could be parameters
ANSI standard in 1966

8. FORTRAN 77 FORTRAN 77 replaced FORTRAN IV as the new standard.
It retained most of the features of IV
It added
Character string handling
Logical loop control statements
And a If with a optional else statement

9. Data Types
FORTRAN 77 explicitly permits data types of integer, real, double precision, complex, logical, and characters.

10. Real Data Types Represent decimal numbers It uses scientific notation

11. Double Precision Data Types
Instead of E it used D
1D2 100

12. Complex Data Types Built in complex number data type
Which occupies 2 bytes
The first byte in the pair represents the real part of the complex data type.
The second byte represents the imaginary part of the complex item.
represented as follows
Numeric Value
(4.61,-6.81) – 6.81i
(-10,5) i

13. Program Structure
A FORTRAN program is a collection of subprogram definitions.
Subprograms may be a FUNCTION that returns values, a SUBROUTINE that doesn’t return a value, and one must be the “main program”

14. Main Program
The main program receives control of the processor when an executable program is loaded for execution.
There can be only one main program in an executable program.
That main program is identified by the fact that it does not have a FUNCTION, SUBROUTINE, or BLOCK DATA statement as its initial statement.

15. Intrinsic Functions FORTRAN 77 has many intrinsic functions Examples
SQRT( ) square root
FLOAT( ),INT ( ) type conversions
COS( ),SIN( ), TAN( ) trig functions

16. Statement Functions
Statement functions are one line defined functions that is internal to the program unit in which it is defined
Example of a statement function
ROOT(A,B,C) = (-B+SQRT(B**2-4.0*A*C))/(2.0*A)

17. Subprograms
The main abstraction devices in FORTRAN 77 are the subroutines and functions.
The subroutine definition
SUBROUTINE SWAP (I,J)
M = I
I = J
J = M
RETURN
END
Functions are structurally similar to subroutines.

18. Control Structures GOTO statements IF statements DO statement
CONTINUE statement
STOP and PAUSE statements
END statement

19. GOTO Statements
The GOTO statement is used to direct program control to indicated by the statement number specified in the respective GOTO statement
Three types of GOTO statements
Unconditional GOTO 100
Computed GOTO(1,2,3)I
Assigned GOTO I,(1,2,3)

20. IF Statements Contains IF, ELSE IF, ELSE, END IF Example IF(Q) THEN
A=B
C=D
ELSE IF (R) THEN
E=F
G=H
ELSE
X=Y
Z=W
END IF

21. DO Statement The DO statement is used to establish a controlled loop
Example DO
DO 10 I = 1,10,1

22. CONTINUE,STOP PAUSE, and END STATEMENT
The CONTINUE statement serves as a point of reference in a program
No operational function is performed
It is frequently used in DO loops to provide a terminal statement
The STOP and PAUSE statements do a similar task
The STOP terminates execution
The PAUSE terminates execution, but leaves the program in a resumable state
The END statement marks the physical end of a program

23. EVALUATION
Readability
Writability
Reliability
Cost

24. Readability
FORTRAN 77 is not to hard to read on a small scale, but when many GOTO statements are involved it gets very difficult
Identifiers can only be six characters long

25. Writability Depends on what you are using it for.
Is a pretty simply language

26. Reliability Is not very reliable Only static type checking
Lack of exception handling

27. Cost Cheap Lots of free resources/compilers
A fairly easy language to learn

28. Bibliography
Marshall, A C. A Brief History of FORTRAN Sept
ibiblio.org. A Brief History of FORTRAN. No date
American National Standards Institute, Inc. American National Standard Programming Language FORTRAN. April 3,
Chivers, Ian D. Sleightholme, Jane. Interactive FORTRAN 77: A Hands on Approach 2nd ed
William, Waite. FORTRAN 77 Semantic Analysis. No date.
Bellis, Mary. Inventors of the Modern Computer. No date.
Page, Rex. Didday, Rich. Alpert, Elizabeth. FORTRAN 77 for Humans, 3rd ed West Publishing Company
Katzan, Harry Jr. FORTRAN 77, Computer Science Series Van Nostrand Reinhold Company