OpenVMS Migration Software for VAX to Alpha Systems Translating Images

This manual describes the OpenVMS Migration Software for VAX to Alpha Systems (OMSVA), focusing on the VAX Environment Software Translator (VEST) utility.

Key Points:

• Purpose: OMSVA facilitates migrating OpenVMS VAX applications to OpenVMS Alpha systems by translating VAX executable or shareable images into equivalent OpenVMS Alpha images.
• Primary Tool (VEST): VEST is the core utility that performs the image translation. It analyzes VAX code, detects dependencies and potential issues, and generates Alpha AXP code, storing information in various files (.IIF, .HIF, .SIF).
• Translated Image Environment (TIE): This run-time environment on OpenVMS Alpha systems transparently supports translated images, allowing them to execute as if on a VAX system, often with comparable or better performance. TIE also handles interpreting VAX code that VEST could not translate.

• Supporting Tools:

  • VEST/DEPENDENCY: Identifies image dependencies to ensure correct translation order.
  • FLOWGRAPH: Creates graphical representations of program flow or image dependencies.
  • DSTGRAPH: Illustrates unaligned and skewed data in VAX images, which can affect Alpha performance.

• Key Functionalities:

  • Automated Translation: Translates images automatically without human intervention for code analysis and translation.
  • Image Analysis: Provides insights into an image's characteristics, translatability, and potential performance issues using qualifiers like /AUDIT.
  • Performance Enhancement: Explains how to use VEST qualifiers, TIE run-time statistics, and run-time feedback (.HIF files) to optimize translated image performance.
  • Interoperability: Details how translated images can call and be called by native Alpha images, including procedures for building "jacket images" and handling shareable image variants.
  • Information Files: Describes the syntax and use of various information files (.IIF, .HIF, .SIF, .LIF) that guide VEST's translation process and manage symbol ordering.

• Audience: Intended for users translating VAX applications, developers creating translated shareable images, and those analyzing VAX images for migration strategies or source code modification.

• Structure: The manual is divided into a User's Guide, Developer's Guide, and Reference Information (appendices covering commands, messages, debugging, restrictions, and VAX instructions).