HP 3000 Manuals

Trap Handling Programmer's Guide

What are Traps? 

A trap involves the interruption, and possible termination, of a running
process as the result of some event.  Some events are detected in the
hardware and, therefore, are known as hardware traps.  Division by zero,
result overflow, and data memory protection traps are examples of
hardware traps.  Other events are detected by the operating system or by
subsystems.  These events are called software traps.  Examples of
software traps are stack overflow and violations of callable intrinsics,
such as passing illegal parameters or invoking an intrinsic without
having the required capability class.

MPE/iX 5.0 Documentation