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.

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CobaltFire 4 hours ago | parent | next [-]

Having worked on nuclear plants (as a reactor operator) around that time this doesn't surprise me in the least.

Thats far more advanced than the systems I worked with, one of which reported rod position via resistance measurement on a brushed cylinder (one for angular and one for depth).

Cleaning and calibrating those was a constant maintenance item every time the reactor was shut down.

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Froedlich 2 hours ago | parent | prev | next [-]

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.

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zx8080 2 hours ago | parent | next [-]

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

	▲	vincent-manis an hour ago \| parent [-]
		When Xerox established PARC, they asked the assembled scientists what computer they wanted. The majority view was a DEC PDP-10 KA10, with the BBN memory management unit that let it run Tenex (the ancestor of DEC TOPS-20). Xerox couldn't really buy a competitor's mainframe, so they built MAXC (maximum access computer), which was a complete emulation of the Tenex machines.

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betaby 2 hours ago | parent | prev [-]

That's interesting. That means there are fewer checks for hardware than software?

	▲	soulofmischief an hour ago \| parent [-]
		Hardware is more amenable to static analysis than running programs which may receive an arbitrary number of inputs and express an arbitrary number of possible intermediate states. I am interested in how firmware is treated, since perhaps in the case of these old machines it's small enough to be analyzable or at least cloned bit-for-bit.

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kccqzy 4 hours ago | parent | prev | next [-]

Did they not need NRC recertification when they moved from a physical machine running AmigaOS to an AmigaOS emulator?

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freeli 3 hours ago | parent [-]

That is an advanced question best asked of the folks in charge of the plant. At the time I was just trying to figure out how to explain to the IT auditors why there was no antivirus software on this piece of crap.

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CursedSilicon an hour ago | parent [-]

Could you skirt around it and just remark "there are no viruses for AmigaOS"

(Probably not literally true. But functionally true in the sense that they were likely transmitted via infected floppy disks, of which there'd be virtually none left in the wild in 2007)

	▲	freeli an hour ago \| parent [-]
		It wasn't the AmigaOS running in the emulator that they were worried about, it was the Windows system running the emulator. (Not that the average IT auditor there could have understood the difference.)

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vincent-manis an hour ago | parent | prev | next [-]

This reminds me of the apocryphal story of the IBM System/360 running a 1410 emulator that ran an IBM 705 simulator that ran a business-critical application.

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icedchai 3 hours ago | parent | prev | next [-]

I'm curious, how did the hardware present itself? It couldn't have been an Amiga Zorro card since it would've been impossible to get that into a PC. Did it connect over a serial or parallel port?

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freeli 3 hours ago | parent [-]

I recall it being some custom ISA card with connectors on the back. The emulation software had drivers that interfaced directly with the card.

	▲	icedchai 3 hours ago \| parent [-]
		Interesting! So they were able to port the hardware but not the software for whatever reason?

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ikidd 3 hours ago | parent | prev | next [-]

NT4.0 in 2007? That wasn't even very late. I was replacing NT4 servers into the early 10s. Car dealerships were terrible for keeping that crap around.

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DoctorDabadedoo 2 hours ago | parent | prev | next [-]

I wonder if there is push in the public sector for open source software/hardware for cases like this.

I completely get the decisions over time here, but it's unsettling having a relevant piece of software (reports are important too!) working on with parts from ebay, in 50 years time they might be gone.

	▲	NegativeK 38 minutes ago \| parent [-]
		I've dreamt of governments hiring devs with promises of full time OSS work. It _might_ get some people over the lower salaries of government work. But I overheard a state CIO once say "We configure, we don't create". That's to say nothing about opinions of open source that rival early 2000s Microsoft. For old ass critical software and hardware, the org can always have a backlog of hardware and contingency plans (paying someone to fix the hardware, paying someone to create a fully certified and modern solution..) for when they start running out of parts.

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gerdesj 3 hours ago | parent | prev | next [-]

"Windows NT 4.0 machine running as late as 2007"

lol. I know a ... factory, that had a BBC model B (with a rather complicated wiring loom) still doing a job around that time.

The IT supplier at the same factory went to a museum in Cambs. around late '90s, early '00s to ask if they could buy an exhibit because something had failed locally. The museum gave them the part.

That was just aerospace and nothing fancy like your nuke plant!

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TMWNN 3 hours ago | parent | prev [-]

>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.

Vernor Vinge's A Deepness in the Sky depicts a human society thousands of years in the future, in which pretty much all software has already been written; it's just a matter of finding it. So programmer-archaeologists search archives and run code on emulators in emulators in emulators as far back as needed. <https://web.archive.org/web/20231114211656/http://www.gareth...>

(Heck, recently I migrated a VM to its third hypervisor. It began as a physical machine a quarter century ago.)