Native Mode and Compatibility Mode

MPE/iX provides two run-time execution en vironments: Native Mode (NM) and Compatibilit y Mode (CM). MPE/iX dynamically and transparen tly coordinates and c hanges modes as required b y applications.

NM is the native MPE/iX run-time en vironment. Source code has been compiled in to the 900 Series nativ e instruction set. NM is the preferred en vironment for the 900 Series and pro vides the highest performance from the systems through the use of demand paged virtual memory and memory mapped ￿les.

CM provides object code compatibilit y between MPE V/E based systems and 900 Series computers. CM allo ws 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 pro vides a working MPE V/E environment, including MPE V/E code and stac k 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 transparen tly switches between modes for system routines. MPE/iX has a Switc h Subsystem that determines if code is in NM or CM and automatically switc hes between them, as needed, while the routine is running. When the called routines are in the other mode, users must write their o wn switching routines.

900 Series Migration

The use of Compatibilit y Mode (CM) and migration utilities pro vides smooth, ￿exible migration to 900 Series systems. The high degree of object code compatibility bet ween MPE V/E and MPE/iX operating in CM allows y ou to store any MPE V/E based application object code program written in a language supported on MPE V/E, restore it on a 900 Series system, and run it in MPE/iX Compatibilit y Mode. You can move data bases to a 900 Series system in the same w ay.

900 Series systems are fully up ward compatible with other systems in the HP 3000 family . Migration tools are pro vided to facilitate upgrading to the 900 Series in stages, as y our schedule permits, without in terruption of operations. Migration to the 900 Series pro vides:

Object code compatibilit y: a simple store/restore procedure allo ws you to move MPE V/E applications and data to the 900 Series. Y ou can back up applications and databases on a tape and restore them on a 900 Series system without modi￿cation. The applications and databases run on the 900 Series in CM.

Source code compatibilit y: you can recompile applications for maximum performance

by using Native Mode (NM) optimizing compilers, whic h improve performance. You can achieve maximum database performance b y using softw are utilities to transform databases into NM.

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