OpenVMS!? Never heard of it. Well, actually, I've heard of it. Wasn't that the operating system that everyone expected Digital Equipment to use in the 1980s to take over scientific computing in the entire known world? Ah, what a difference a few short years can make. I didn't know there were machines out there still running this OS.

In separate correspondence with Steve I mentioned that IDL 5.4 (released in 2000) was officially supported on OpenVMS 7.1. IDL 5.4 was the last version of IDL that works on OpenVMS. OpenVMS 7.3-2, which is your current platform for IDL 5.4, is in fact the newest version of the OS on which I've heard that IDL 5.4 can run. Sorry, I don't have information about IDL 5.4's compatibility with OpenVMS 8.4. For now, if you are unable to obtain confirmation about IDL's compatibility on OpenVMS 8.4, an idea might be to continue to run the current OS alongside the newer version OS through a dual boot set up or virtual machine technology. If there exists something like Oracle Virtualbox that can support OpenVMS, then perhaps you could even run OpenVMS 7.3-2 simultaneously from within your OpenVMS 8.4 session. I hope this can be helpful. Best regards, Jim Uba