Unsupported VMS FORTRAN

Most VMS FORTRAN extensions are incorporated into the f77 compiler. The compiler writes messages to standard error for any unsupported statements in the source file. The following is a list of the few VMS statements that are not supported.

• DEFINE FILE statement

• DELETE statement

• UNLOCK statement

• FIND statement

• REWRITE statement

• KEYID and key specifiers in READ statements

• Nonstandard INQUIRE specifiers

  • CARRIAGECONTROL

  • DEFAULTFILE

  • KEYED

  • ORGANIZATION

  • RECORDTYPE

• Nonstandard OPEN specifiers

  • ASSOCIATEVARIABLE

  • BLOCKSIZE

  • BUFFERCOUNT

  • CARRIAGECONTROL

  • DEFAULTFILE

  • DISP[OSE]

  • EXTENDSIZE

  • INITIALSIZE

  • KEY

  • MAXREC

  • NOSPANBLOCKS

  • ORGANIZATION

  • RECORDTYPE

  • SHARED

  • USEROPEN

• The intrinsic function, %DESCR

• The following parameters on the OPTIONS statement:

  • [NO]G_FLOATING

  • [NO]F77

  • CHECK=[NO]OVERFLOW

  • CHECK=[NO]UNDERFLOW

• Some of the INCLUDE statement

  Some aspects of the INCLUDE statement are converted. The INCLUDE statement is operating system-dependent, so it cannot be completely converted automatically. The VMS version allows a module-name and a LIST control directive that are indistinguishable from a continuation of a UNIX file name. Also, VMS ignores alphabetic case, so if you are inconsistent about capitalization, distinctions are made where none are intended.

• Getting a long integer--expecting a short

  In VMS FORTRAN, you can pass a long integer argument to a subroutine that expects a short integer. This feature works if the long integer fits in 16 bits, because the VAX addresses an integer by its low-order byte. This feature does not work on SPARC systems.

• Those VMS system calls that are directly tied to that operating system

• Initializing a common block in more than one subprogram

• Alphabetizing common blocks so you can rely or depend on the order in which blocks are loaded. You can specify the older with the -M mapfile option to ld.

• If you use the defaults for both of the following:

  • The OPEN option BLANK=

  • The BN/BZ/B format edit specifiers

    then formatted numeric input ignores imbedded and trailing blanks. The corresponding VMS defaults treat them as zeros.