Doctor Fortran

(Deleted from Intel site, recovered thanks to archive.org!)

MAGIC WORD XYZZY

For computer geeks of a certain age, such as yours truly, it was an opportunity to relive the glorious past when Dennis Jerz announced that an early 1977 version of Will Crowther’s Adventure game source code had been discovered. Adventure was one of the first puzzle-exploration games and it not only captured the imagination of computer users worldwide when it became more widespread in 1978, but it inspired many future games such as the popular Zork and even many of today’s graphics-heavy computer games. Not bad for a text-only game written in Fortran. Right, Fortran.

The other day, I posted something in comp.lang.fortran in response to a post asking for a new feature in the Intel Fortran compiler. I suggested that the best thing to do was to submit an issue to Intel Premier Support asking for the feature since the more customers who ask for a feature, the easier job the Fortran project manager has in justifying it. This prompted a startled reply from someone who thought that I was the Intel Fortran project manager. “Heck no,” I replied, “I’m not even the most senior engineer on the project!” Well, really, I’m not on the compiler project itself anymore, but I still sit and work with those who are. Yes, I started my Fortran career at DEC in 1978, but there are others on the team who have been at it longer.

2007 will mark the 50th anniversary of the Fortran language, which was first introduced in 1957. The British Computer Society is sponsoring a retrospective on Fortran in January – perhaps there will be a US event as well.

“Doctor, my stack is overflowing! What does it mean?! Is there a cure?!” The Doctor frequently sees questions like these, and he realizes it’s time for a general article on the subject of stack allocation, as well as the other memory allocation types, static and dynamic.

One of the more obscure error messages you can get at run time is Access Violation, which the Visual Fortran run-time library reports as error number 157. The documentation says that it is a “system error,” meaning that it is detected by the operating system, but many users think they’re being told that their system itself has a problem. In this article, I’ll explain what an access violation is, what programming mistakes can cause it to occur, and how to resolve them.