Fortran

Invented by : John Backus & IBM

Invented in year : 1954

FORTRAN is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing. In other words, it is a high-level computer programming language used especially for scientific calculations. A high-level programming language is a programming language with strong abstraction from the details of the computer. The term ‘FORTRAN' has been derived from: FORmula TRANslation. It was developed in the 1950’s for scientific and engineering applications. It was and is still being used for numerical weather prediction, finite element analysis, computational fluid dynamics, computational physics and computational chemistry. Full Caps – FORTRAN has now been changed to ‘Fortran’. In modern times, Fortran is one of the top and most popular language in scientific and industrial programming.

Fortran History

In the 1950’ computer programming language was slow and highly complex task. Moreover, very few understood it. John Warner Backus, an American computer scientist wanted to simplify and speed the task of programming. He wanted the computer language to be easily understood by all. At the same time IBM had developed its 701 computer. Though, the computer was fast, there were not enough tasks to keep it busy. The total interdependence of computer software and computer hardware needed to be understood fully. It was not an easy task as there were very few experts in this field.

This task was solved by Backus 3 years after he joined the IBM. In late 1953, John W. Backus submitted a proposal to his superiors at IBM to develop a more practical alternative to assembly language for programming their IBM 704 mainframe computer. Thus began the invention of FORTRAN. John Warner Backus and his team at IBM worked tirelessly to achieve the purpose. The team comprised of programmers Richard Goldberg, Sheldon F. Best, Harlan Herrick, Peter Sheridan, Roy Nutt, Robert Nelson, Irving Ziller, Lois Haibt, and David Sayre. John Backus wanted a programming language that was closer in appearance to human language; Fortran began as a digital code interpreter for the IBM 701 and was originally named Speedcoding. Headed by the genius of Backus, a programming language was developed that resembled a combination of English shorthand and algebra. It was very similar to algebraic formulas which scientists and engineers used daily in their work. The simplification of FORTRAN made programming an easy task for the people.

By 1954, FORTRAN was invented for IBM in south San Jose, California - by John Backus and his team. It was released commercially in 1957. The first computer to run the first compiler was the IBM 704, which John Backus helped design. The team used the name ‘Fortran’ because one of their principal aims was 'Formula Translation'. Fortran language came complete with control structures and facilities for input/output. Fortran became popular quite rapidly and compilers were soon produced for other IBM machines.

Development in the Invention of FORTRAN

Versions

IBM developed FORTRAN II and III during 1958. FORTRAN II supported procedural programming by allowing user-written subroutines and functions which returned values, with parameters passed by reference. FORTRAN III allowed for inline assembler code among other features.

By 1960, various versions of FORTRAN were available for the IBM 709, 650, 1620, and 7090 computers. Amongst these version was mad available for IBM 1401 by an innovative 63-pass compiler that ran in only 8k of core.

In 1962, FORTRAN IV was released for the IBM 7030 computer. Furthermore, it’s later versions were developed for the IBM 7090 and IBM 7094.

Standardisation

Fortran 66 - Soon other manufacturers started to design Fortran compilers for their own hardware. By 1963, all the major manufacturers joined in and various Fortran compilers came into existence, many of which were more powerful than the original. However, it caused problems with incompatible dialects. In 1966, an American National Standard was defined for Fortran, known as Fortran 66. But the Fortran66 standard only specified a set of language features which had to be present: it did not prevent other features being added.

Fortran 77 - With the passage of time extensions increased rapidly and a need for further standardization came forth. As a result another standard was developed, it was called Fortran77, possibly because it was developed in 1977. It was released in 1978 by a committee of the American National Standards Institute (ANSI) and was subsequently adopted by the International Standards Organisation (ISO). The ANSI Standard actually defines two different levels for Fortran77. The simpler form, subset Fortran, was intended for use on computers which were too small to handle the full language. The whole of the Fortran77 Standard is included as a proper subset, so existing (standard-conforming) Fortran programs will automatically conform also to the new Standard.

FORTRAN 77 Updations

• DO loops with a decreasing control variable (index).
• Block if statements IF ... THEN ... ELSE ... ENDIF.
• Before F77 there were only IF GOTO statements.
• Pre-test of DO loops. Before F77 DO loops were always executed at least once, so you had to add an IF GOTO before the loop if you wanted the expected behaviour.
• CHARACTER data type. Before F77 characters were always stored inside INTEGER variables.
• Apostrophe delimited character string constants.
• Main program termination without a STOP statement.

Fortran 90 – After a long period of time, Fortran77 was officially replaced (though still in use in some places mainly to re-compile legacy code) by the advanced Fortran 90. It was released as an ISO standard in 1991 and an ANSI Standard in 1992.

Fortran 90 Updations

• Free format source code form (column independent).
• Modern control structures (CASE & DO WHILE).
• Records/structures - called "Derived Data Types".
• Powerful array notation (array sections, array operators, etc.).
• Dynamic memory allocation.
• Operator overloading.
• Keyword argument passing.
• The INTENT (in, out, inout) procedure argument attribute.
• Control of numeric precision and range.
• Modules - packages containing variable and code.

There were subsequent updates in 1996 and 2004. By this time 4th and 5th generation languages started replacing FORTRAN, in order to retain compatibility with old programs, Fortran kept on adding new features rather than by removing old ones.

Role of the Invention of FORTRAN in the improvement of human life

• The first FORTRAN compiler was a milestone in the history of computing during the 1905’s as computers had very small memories, like 15KB and were very slow. Fortran became the most widely used computer language with compilers available for almost every type of computer. Fortran77 was quite good at handling character strings as well as numbers and also has powerful file-handling and input/output facilities; it suited a much wider range of applications than before. Thus, Fortran shortened the process of programming and made computer programming easy. With some training, people could themselves perform programming.
• Fortran established the criteria of creating standards for all major programming languages. The first step in achieving portability was to ensure that a standard form of programming language is acceptable everywhere.
• Fortran was started to be used for programming air traffic control systems, military applications, parallel computer research, payroll calculations, scientific applications and video games.
• Fortran programs enabled the ease with which they could be moved from one computer system to another, making it portable as compared to existent languages at that time. This also made computer programming more accessible to a vast number of people. This portability was further extended with the growth in computer networks.
• Its invention led to the development of other high level programming languages.