VMS to Raspberry Pi: Following MPE’s lead?

A new discussion on the OpenVMS newsgroup is kicking around the idea of running VMS on a Raspberry Pi processor. Some of the regular visitors to the group believe the Pi is the next logical destination for the venerable VMS, now that work is up to speed on an x86 version.

Bootstrap design notes are in place to put a skunkworks project like Pi OpenVMS into play. The Raspberry is the hardware that helped drive the Rover on the surface of Mars. Pi is a wonderful story, however, of how a community launched a processor into such demanding jobs.

The commercial payoff might be hard to show. This sort of project demonstrates flexibility, though, an aspect that legacy OS’s have to prove more than commodity environments.

For example, Robert Mills was working to put an HP 3000 in his pocket. The UK programmer got the MPE V version of an HP 3000, the Series III Simulator, running on a Dell Inspiron desktop. The Simulator gives Intel-based servers the ability to mimic the long-retired Classic HP 3000 hardware. In the same manner for the fully commercial market, Stromasys Charon virtualizing software lets HP’s PA-RISC processing be hosted on Intel systems.

Mills says he’s working his way backwards in time for 3000 computing. Once his simulated HP disk drives can be replicated, he’ll have a 3000 circa 1983 running on his Dell system.

The simulator on my main computer (Dell Inspiron 3668 running Linux Mint 18.3 with Cinnamon Desktop) has two HP7925 (120Mb) disc drives, two HP7970E tape drives, and 1024K words of memory. The simulator reports that it is executing machine instructions approx 95 times faster than a real Series III. With a little bit of work I could increase the number of HP7925s to eight. This would give me a system that equals, except for the processing speed, a system I worked on during 1981-83.

It’s fun to note that his simulated Classic 3000 runs 95 times faster than the original HP hardware. This echoes the upgrade potential of a system virtualizer like Charon. Host the emulated 3000 on faster Intel hardware and you see performance increase. The size of the 3000 itself is decreasing for Mills in next step.

“The next thing I plan to do is try and install the Simulator on my Raspberry PI 2B, which has a 2Tb Seagate Expansion Drive,” Mills says. “If it works, I’ll have an HP 3000 that I can carry in my pocket.”

One VMS newsgroup contributor suggested that small-format processors might help VMS retake some of the embedded market for IT. “How many licenses do you think they could sell for x86-64?” Bill Gunshannon asks. “Your answer would be no more accurate than mine. I seriously think there could be a market for an rPi version of VMS.”

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