HP 3000 Manuals

Alternate Returns [ HP FORTRAN 77/iX Migration Guide ] MPE/iX 5.0 Documentation

HP FORTRAN 77/iX Migration Guide

Alternate Returns 

Alternate returns are implemented differently in the two compilers.
Because of this difference, a FORTRAN 66/V program cannot call an HP
FORTRAN 77/V subroutine using the alternate return mechanism.
Conversely, an HP FORTRAN 77 program cannot call a FORTRAN 66/V
subroutine using an alternate return.

MPE/iX 5.0 Documentation