Guaranteed it’s a few weeks or months. Nothing is that complicated. Especially if it runs on windows 3.11.

I find it heartwarming that you've never seen software more complicated than a few months of work. I wonder what you typed that message on.

Again, what insanely sophisticated system could possibly be running on 3.11? Identify the inputs and outputs and go from there. It’s probably a driver. Or something that operates an antique piece of hardware. Dig into the binary protocol. Pen test the heck out of it. Reverse engineering is not hard.

I’ve done some wild shit in my day. Gotta think outside the box and go to first principles. If it looks like a duck, quacks like a duck and walks like a duck it’s a duck. You can replace things pretty easily when you identify the perimeter of a piece of software.

These days we have pretty powerful decompilers too. I’d posit I could replace this tech for the same cost of one year of whoever they are hiring for this to perpetuate the antiquated crap.

In general there is no real reason why a software running on Windows 3.11 could not contain 100 years of development time. What seems less likely is that the majority of that code would be highly hardware or system specific and would require porting to a modern platform. But as we do not really have any idea what kind of system we are talking about, it is hard to speculate.

If you think that "Identify the inputs and outputs and reverse engineer it which isn't hard" is all that's needed to re-create some bespoke piece of software then I hope you will never-ever have the chance to put this in to practice for this sort of safety-critical stuff.

"Oh yes, we missed that one output that only happens under these specific conditions and now the train crashed – oops!"

that software is certified and tested to work with those trains...do you know what it takes to test and get certified?

Terrible attitude.

“Hey, our software works and is certified but it’s ancient and no one knows how to maintain it. If was written 30 years ago on a version of windows that doesn’t even support the internet. We need to upgrade and recertify”. This is an easy argument.

"These trains have been working fine for 32 years, after we ironed out some bugs with the software in the first six months of use. We absolutely don't want to have trains failing, as it's very disruptive for passengers, so let's keep the existing software working for a few more years. The trains will be scrapped in 2030 anyway."