Hat tip to Gilberto Persico for this:
In a blog post last month I looked at how a Raspberry Pi can be used to emulate a formidable IBM mainframe, and in this post I describe how a pair can be used to emulate VAX computers which can then be configured to form a VMScluster.
The MicroVAX 3900 hardware being emulated this time is a little more modern and somewhat smaller than the IBM 4381 processor, but the VAX architecture and OpenVMS operating system are no less impressive. On introduction in 1989 an entry level MicroVAX 3900 would have set you back over $120,000 and, as with IBM’s VM operating system, you’d be mistaken if you thought that OpenVMS was dead and buried as it runs many mission critical workloads today.
Emulation of the VAX hardware has been made possible by a pretty amazing piece of software called SimH. In order to be able to run OpenVMS on this a licence is required, but fortunately these are available free of charge via the OpenVMS Hobbyist programme.
The SimH software is configured to emulate a MicroVAX 3900 with 64Mb of memory, 1.5Gb disk and a CD-ROM drive. An ISO file containing an image of the OpenVMS installation media is attached to the virtual CD-ROM drive and the emulator is booted. The steps to install the software are reasonably simple and the image below shows part of the installation process.