HP 3000 Manuals

Getting Started as an MPE/iX Programmer Programmer's Guide

MPE Operating Systems 

All HP 3000 models run under the Multiprogramming Executive (MPE)
operating system.  It is a disc-based operating system that manages all
system resources and coordinates execution of all programs running on the
system.  The version of MPE used varies from one model to another.
Figure 1-1  shows the on-line access capabilities common to all MPE
operating systems.


          Figure 1-1.  MPE/iX On-line Access Capabilities 

The system simultaneously performs inquiry and update, program
development, batch processing, and communications to other systems.  All
functions are available on-line (in sessions) or in batch mode (in
jobs)submitted to the system.  The same programs, files, and commands
apply for both types of use.  Figure 1-2  shows the high-level tools
available on the 900 Series HP 3000.


          Figure 1-2.  900 Series HP 3000 High-level Tools 

MPE/iX and MPE V/E Operating Systems 

Since the 900 Series HP 3000 was introduced, Hewlett-Packard supports two
types of MPE operating system; MPE V/E and MPE/iX, which stands for MPE
with eXtended Large addressing.  The "V" in the name MPE V/E is the Roman
numeral for "5." MPE V/E is the operating system formerly called MPE. MPE
V/E is supported on Series 37 through the Series 70 systems.  MPE/iX is
the operating system for 900 Series systems.  It is designed to take full
advantage of HP Precision Architecture (HP-PA). MPE/iX has the
performance and ease-of-use of MPE V/E, plus additional functions and
capabilities.  It is upwardly compatible and has a user interface
consistent with MPE V/E. MPE/iX is object code and source code compatible
for programs developed on MPE V/E. It has two run-time environments that
are transparent to the user:

   *   Compatibility Mode (CM), which provides object-code compatibility
       with MPE V/E-based applications.

   *   Native Mode (NM), which provides full performance benefits and
       advanced capabilities of HP-PA.

Naming Conventions for HP 3000 Systems and Software 

When the 900 Series was added to the HP 3000 family of computers,
Hewlett-Packard instituted a new naming convention for HP 3000 software
products; the addition of the suffix "/V" or "/XL" to a product name.
Software products that previously had the suffix "/3000" now have the
suffix "/V." For example, the product named IMAGE/3000 is now named
IMAGE/V, and the product named COBOL/3000 is now named HP COBOL/V.

The "/V" suffix indicates that a product is designed for use with the MPE
V/E operating system.  This product can also be used with the MPE/iX
operating system running in Compatibility Mode.  A compiler with the
suffix "/V" (for example, RPG/V) generates object code that runs under
MPE V/E and MPE/iX (in Compatibility Mode).

The "/XL" suffix indicates that a product is designed for use with MPE/iX
running in Native Mode.  A compiler with the suffix "/XL" (for example,
HP COBOL II/XL) generates object code that runs with MPE/iX in Native
Mode.  Figure 1-3  shows an example of naming conventions.


          Figure 1-3.  HP 3000 Software Naming Conventions Example 

Computers in the HP 3000 family that operate under the MPE V/E operating
system are frequently called "MPE V/E-based systems." Computers in the HP
3000 family that operate under the MPE/iX operating system in native mode
are frequently called "MPE/iX-based systems." This includes 900 Series
systems.

Native Mode and Compatibility Mode 

MPE/iX provides two run-time execution environments:  Native Mode (NM)
and Compatibility Mode (CM). MPE/iX dynamically and transparently
coordinates and changes modes as required by applications.

NM is the native MPE/iX run-time environment.  Source code has been
compiled into the 900 Series native instruction set.  NM is the preferred
environment for the 900 Series and provides the highest performance from
the systems through the use of demand paged virtual memory and memory
mapped files.

CM provides object code compatibility between MPE V/E based systems and
900 Series computers.  CM allows you to move applications and data to 900
Series computers without changes or recompilation.

MPE/iX is a compatible superset of MPE V/E. CM provides a working MPE V/E
environment, including MPE V/E code and stack structures and most
callable MPE V/E system intrinsics.

MPE/iX Mixed Modes 

Applications can run partly in Native Mode (NM) and partly in
Compatibility Mode (CM). MPE/iX transparently switches between modes for
system routines.  MPE/iX has a Switch Subsystem that determines if code
is in NM or CM and automatically switches between them, as needed, while
the routine is running.  When the called routines are in the other mode,
users must write their own switching routines.

MPE/iX 5.0 Documentation