MPE/iX Features

• 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).