Thread

1. freeli · 1790375986 · focus · HN ↗

   A certain nuclear power plant had a Windows NT 4.0 machine running as late as 2007. The reason is interesting.

   The machine's purpose was to report status of the control rods that mitigate nuclear reactions. Basically, "are the rods inserted, and if so, how many / how far?". I want to emphasize that this was reporting only, NOT control.

   The original software was written back in the 80's, when the plant was originally commissioned, for AmigaOS. Of course, it's hard to buy Amigas anymore, and the original one died long ago (nobody remembers when).

   So in the mid '90s, the utility purchased an AmigaOS emulator that ran on Windows NT 4.0, which was current at the time. The emulator (IIRC) was developed by a firm in the UK. The firm went out of business sometime in the late '90s. The control rod monitoring software ran under this emulator on top of NT4.

   Windows NT 4.0 was the last OS to allow the emulation software direct access to the physical hardware that produced the status signal. Later versions of Windows abstracted the hardware access away, and the monitoring software broke. Because the emulation company had gone belly up, there was no way to fix the incompatibility.

   So the utility had a choice: get new hardware/software certified (by NRC?), or keep doing what they were doing with the software (and hardware) that they had. They chose the latter.

   So this is how, in 2007, during a tour of the facility, I stumbled across a Pentium 1 system running an AmigaOS emulator on Windows NT 4.0 that was responsible for displaying the status of the control rods of a nuclear power plant.

   Spare hardware for this setup was purchased off of eBay and stocked on an adjacent shelf.

   1. Froedlich · 1790382795 · focus · HN ↗

      A friend works for an airline as a flight simulator tech. Their entire software stack, including the compiler and OS, is FAA-certified.

      Then their ancient Honeywell(?) mainframes reached end-of-life they scouted for compatible hardware, of which there was none. The cost of certifying new software, plus the time involved, was astronomical. So, after consulting with the FAA, they paid a hardware company to clone the ancient mainframes in modern silicon. The FAA signed off on it, and they had all-new computers - much smaller than the originals - running the old stack.

      1. zx8080 · 1790384009 · focus · HN ↗

         It's _very_ hard to believe some company to simply "clone the mainframe" into chip. Mind sharing any link to this effort?

         1. mitxela · 1790419194 · focus · HN ↗

            Custom chips aren't as expensive as you think. About a few million dollars for the design and a hundred thousand chips, way out of reach for a hobbyist, but accessible to large enough companies. Just because it's opaque to us software people doesn't mean it's not a real industry you can buy things from.

            1. realo · 1790426984 · focus · HN ↗

               And all that expensive engineering is still less costly AND faster (!!) than a new software certification.

               Cannot refrain myself from asking why ...

               1. mitxela · 1790429547 · focus · HN ↗

                  Doesn't seem crazy to me. Which one do you suppose needs more proof of correctness: a cake recipe, or the oven you bake the cake in? The recipe has to be correct or the cake won't work, but the oven just has to hold a temperature.

                  1. realo · 1790435761 · focus · HN ↗

                     That "just" is quite the load-bearing seam ...

                     Particularly when the task here is "just" to measure some rod positions in a constrained 3D space ...

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