HP 3000 Manuals

COBOL/HP-UX Compatibility Guide for the Series 700 and 800

Calls 

DG Interactive COBOL system calls are environment dependent, and are not
supported by this COBOL system.  Note also that under this COBOL system
you cannot pass a switch in a CALL statement; you are advised to use
LINKAGE SECTION items to communicate between programs.

MPE/iX 5.0 Documentation