HP 3000 Manuals

Introduction to MPE XL for MPE V Programmers Migration Guide

Overview of MPE XL and MPE V/E Differences 

When programming in the high level languages available in the Native Mode
(NM) environment, all expansions and contractions of the NM stack are
accomplished by the operating system.  The NM versions of the DLSIZE and
ZSIZE intrinsics do not affect the NM stack.  Instead, they are
implemented to enable your NM program to affect the Compatibility Mode
(CM) stack.

The changes occur mostly because of Hewlett-Packard Precision
Architecture (HP-PA) on the 900 Series HP 3000.  Instead of segmentation,
the MPE XL operating system has demand-paged virtual memory.  The
commands and intrinsics relating to segmentation are maintained for
backward compatibility with MPE V/E, however.

Changed 

Existing MPE V/E features that have been modified on MPE XL include:

MPE V/E features that are changed on MPE XL:

 *  Compatibility Mode Stack Allocation

 *  The following intrinsics:

DLSIZE (NM)
ZSIZE (NM)

Unchanged 

Existing MPE V/E features that are the same on MPE XL include:

 *  The following intrinsics:

DLSIZE (CM)
ZSIZE (CM)

MPE/iX 5.0 Documentation