F7CALG - call a subroutine using the Fortran 66/GMAP call.

Usage:

external target
  ...
call f7calg(target [, arg1, arg2, ...])

Where:

target: is the name of the Fortran 66 routine to be called.
arg1, arg2, ...: are the arguments of subroutine "target".

Description:

F7CALG allows a Fortran 77 routine to call a subroutine which uses the Fortran 66 call sequence. This includes programs written in GMAP, Fortran 77, and Cobol 74.

F7CALG only remaps the call sequence; it does nothing to make runtime libraries compatible. A called Fortran 66 routine must NOT do any I/O. Besides prohibiting READ/WRITE statements, this also means that the called routine must not cause any errors that would cause a library function like SQRT to try to print an error message.

Because of the I/O restrictions, whenever possible it is a much better idea to recompile Fortran 66 routines using the Fortran 77 compiler. Interfacing object decks from both compilers should be regarded as a temporary measure. F7CALG will be of more use in accessing Cobol 74 and stand-alone GMAP routines.