Language-Extensions and Restrictions

BC-FORTRAN77 supports the fully FORTRAN77 standard defined by ANSI/ISO. This standard is often ignored by some special features. I do not recommend the use of these extensions, because they do not comply with the ANSI standard and are therefore not precisely defined.

The most important specialities are: 



    IMPLICIT NONEABC 
 		 INTEGER*1 		 8 bit INTEGER 


INTEGER*2 		 16 bit INTEGER 


INTEGER*4 		 same as INTEGER 


LOGICAL*1 		 8 bit LOGICAL


LOGICAL*2 		 8 bit LOGICAL


LOGICAL*4 		 same as LOGICAL


IMPLICIT NONE 		 turn off all implicit typedefs


COMMON /%adr/ 		 absolute addressed COMMON, adr may be a constant or a simple variable


EQUIVALENCE()		 between CHARACTER and other types and mixing in COMMON blocks


recursive subroutine calls 


max. length of names: 8 chars. (standard 6 chars.)
The most important restrictions are: 


    32kB 
 		 32kB 		 code per subroutine


32kB 		 SAVE/DATA per subroutine or BLOCK DATA


700 		 subroutines per file


500 		 different COMMON blocks per file
There are also some restrictions, which would cause a compile-time-error, if subroutines are unreasonable large. In most cases the 32kB limit would be exceeded anyway.