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Software > OpenVMS Systems > Ask the Wizard HP OpenVMS Systemsask the wizard |
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The Question is: We are about to begin the process of migrating vax c source code written on a vaxstation 4000 openVMS 6.2 over to an Alphaserver 800 OpenVMS 7.1. We also have pro c code and fortran code we will need to port to the alpha and relink. What is the best approach to doing this ? We know we can move the code over to the alpha and try recompiling and linking but we've heard of DECMigrate and were wondering if this would be an appropriate tool to use for this task. We will be maintaining/up dating this code on the Alpha exclusively once we port it over. Thanks Wizard The Answer is : DECmigrate translates older OpenVMS VAX executables for direct operation on OpenVMS Alpha. If you have the application source code and have all necessary prerequisite products available on OpenVMS Alpha, the Wizard would tend to recommend recompilation -- rather than use DECmigrate. This migration can be anything from trivial to involved -- most of the migrations will tend to be easy, but which end of the scale you find yourself working at depends entirely on the coding practices used. First, read through the available application migration documentation for OpenVMS, and for moving from VAX C to DEC C. (The latter is part of the DEC C for OpenVMS VAX documentation set, but not of the DEC C for OpenVMS Alpha set.) The Wizard would recommend installing DEC C on OpenVMS VAX, and moving the existing C code from VAX C to DEC C on OpenVMS VAX first, then to OpenVMS Alpha. This will help isolate the compiler differences -- the VAX C compiler predates ANSI C -- from the architectural differences. The same holds for moving to current releases of OpenVMS, Fortran, and other products -- it is easier to operate at compatible releases. To ease the migration process, configuring the two systems into an OpenVMS Cluster can often be a reasonable approach.
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