gtpg1m13General Information

Migration Aids

The TPF 4.1 system provides the following migration aids to protect your investment:

Virtual File Access (VFA) Enhancements

To improve performance in the TPF 4.1 system, virtual file access (VFA) is always present and active. Your installation can run programs directly from VFA, thereby improving system performance. The online and offline VFA performance monitoring facilities improve your installation's ability to better tune VFA candidates and VFA resources.

System Service Request Enhancements

Enhancements to the macro decoder and supervisor call instruction (SVC) definitions increase an application's ability to request system services.

The primary interfaces for application requests of system services are through macros using the SVC and fast-link macro decoders. (Fast-link macros are macros that do not issue SVCs.) In the TPF 4.1 system, the SVCs allocated for use are increased from 128 to 255, and the SVCs reserved for customer use are increased from 1 to 32. In addition, two SVC entries (one for IBM and one for customers) can be reserved to support a second-level structure. With this secondary or indexed structure, your installation can define more than 32 000 additional macros.

One hundred fast-link macros are reserved for your application's use. Fast-link macros are more expedient than other macros because they do not issue SVCs that cause system interrupts.

Certain restricted-use TPF system macros now check the authorization level of the requesting program before providing the system service. If a program requests a service that it is not authorized to obtain, the service is not granted. This authorization level is specified as part of a program's allocation information.

Improved Inter-Processor Communication (IPC)

Beginning in TPF 4.1 systems, the only supported path for inter-processor communications is through the Multi-Processor Interconnect Facility (MPIF) feature. MPIF is a required feature for the High Performance Option (HPO) feature.

IBM C Language Support

In the TPF 4.1 system, IBM C language support is no longer a product feature. It is incorporated in the base TPF product to allow system and application growth. TPF 4.1 requires installation of either the IBM C/370 or AD/Cycle C Compiler and Library.

Performance Monitoring Enhancements

Several reports are enhanced to be more usable and present additional information. A new report contains a histogram of storage frame usage.

Improved System Initialization

System initialization is easier in the TPF 4.1 system. The file address compute program (FACE) table generation is handled by a new offline FACE table generator program rather than as part of system initialization process (SIP).

Improved Capture and Restore Operations

The capture and restore utility controls the maximum number of simultaneous captures allowed for each tape control unit, DASD control unit, DASD channel path and tape channel path, based on the channel path activity.