HP 3000 Manuals HP 3000 Manuals
MPE/iX Features
The main features of the MPE/iX operating system on a 900 Series computer
include:
* Multiprogramming: concurrent transaction processing, data
communications, on-line program development, and batch processing.
* Extended large addressing: 48-bit virtual addressing.
* Demand paged virtual memory, which transparently manages virtual
memory and eliminates the need for program segmentation.
* Mapped disc files, which eliminates the need for File System
buffering for disc files. This increases system performance for
I/O-intensive applications.
* Concurrent multilingual capability, including HP-extended versions
of C, COBOL, RPG, FORTRAN, BASIC, and Pascal.
* File System, which includes file backup, user logging, security,
and interprocess communication (IPC).
* Access security and complete accounting resources.
* Command interpreter, which includes user-defined commands (UDCs),
command files, conditional job control, extensive on-line help
facility, and descriptive error messages.
* Device and file independence, which simplifies application
development and maintenance.
* I/O System, which provides input/output spooling and a tape label
facility.
* Complete, automatic local and remote terminal management.
* Power fail/automatic restart.
* Interactive Debug facility, which provides windows that allow you
to simultaneously see the environment of the program being tested.
It supports breakpoints, single stepping, calculation of
expressions, macros, and command files.
Multiprogramming
MPE/iX supports multiprogramming, the concurrent execution of multiple
programs. All system resources are available to you as if you were the
only user on the system. While one program is waiting for input, the
system shifts control of the CPU to the next highest program in the
queue. In this way, activities such as transaction processing, on-line
program development, interactive data entry, data communications, and
batch processing can be concurrently performed.
MPE/iX is a multiprogramming, multiuser system. On this kind of a
system, multiple users can share code. For example, when multiple users
access the BASIC/V interpreter, a separate process is created for each
one. They all use the same code (because there is only one BASIC
interpreter on the system), but each user has a unique environment
created by MPE/iX. MPE/iX completely protects one program execution from
interfering with another.
Interactive and Batch Processing
MPE/iX provides interactive and batch processing. An interactive process
is called a session. A batch process is called a job.
In a session, you enter commands and data at a terminal and receive an
immediate response. This is especially useful for data entry and
retrieval, program development, text editing, and any application that is
expedited by direct dialogue with the computer.
In batch processing, you submit a job to the computer. A job is a single
unit composed of commands that request various operations, such as
program compilation and execution, file manipulation, or utility
functions. While a job is processing, there is no user interaction with
the computer unless the job is set up to request information. Jobs can
be scheduled to run at lower priorities than interactive sessions and at
specific times (for example, when system activities are low).