The programming language FORTRAN is the principal language for scientific and technical computations. It was developed originally in 1954 and has been revised several times, to FORTRAN IV and Fortran 77. It has recently been carefully revised, resulting in a modern and powerful language, Fortran 90.

The intent with this new standard is to make Fortran into a useful and efficient language for the scientific and technical computations also towards the end of this decade. The new version contains powerful new features for the treatment of vectors and matrices, several new possibilities to specify the precision, access to environment parameters, intrinsic functions for manipulating floating point numbers, internal procedures and new specifications for storage and interfacing. In addition there is a new improved layout of the source code, new conditional statements, recursion and dynamic memory allocation. Nothing was removed, so Fortran 90 contains the whole of Fortran 77, but offers both easier programming and improved security.

An important requirement at the introduction of a new language is nowadays that the language should be efficient also on parallel systems. This tutorial therefore contains an Appendix on the recent proposed addition to Fortran, High Performance Fortran.

This tutorial assumes that the reader is experienced in Fortran 77. Those parts of Fortran 90 that are already in Fortran 77 are not discussed here. The many programming examples and user exercises illustrate the programming technique and available commands, and makes it easy to get started with writing programs using the new facilities in Fortran 90. All examples have been tested on Sun SPARC (UNIX) and DEC Station (ULTRIX), and on IBM PC with MS-DOS 5 and 6.2.

Bo Einarsson Yurij Shokin

Last modified: 27 January 1996