A long time ago, ..., so add a huge IIRC for the details.
Anyway, a long time ago, in a physic lab class, we had a custom spectrometer device that was controlled using the printer port. (Probably a light, a detector, a diffraction grid and a steppers motor, and perhaps some weird card as an interface to the computer.) It was controlled by a custom Pascal program in the DOS command line.
It was connected to a Win 95 computer that died and we had to replace it with a Win 2000 one. The problem is that anyone can read/write the printer port in Win 95 but that's not possible in Win 2000. [1] We had to make some magic, probably rewrite the program and use some weird device driver to write to the printer port (IIRC again). And multitasking messed the timing. At the end it worked, but upgrading the computer was not easy.
[1] If that makes no sense, replace that with a Win 3.1 to Win 95 transition, but I think it was not that old.
I had similar many years ago in a custom paint shop. We had an expensive colorimeter that interfaced over serial with a program that ran in DOS.
When the pysical computer gave out, I replaced it with a reasonably new one but instead of using a modern OS I installed MS-DOS in order to get it up and running as reliably and quickly as possible.
If I were doing the same today, I'd likely get a new computer and install FreeDOS.
Anyway, a long time ago, in a physic lab class, we had a custom spectrometer device that was controlled using the printer port. (Probably a light, a detector, a diffraction grid and a steppers motor, and perhaps some weird card as an interface to the computer.) It was controlled by a custom Pascal program in the DOS command line.
It was connected to a Win 95 computer that died and we had to replace it with a Win 2000 one. The problem is that anyone can read/write the printer port in Win 95 but that's not possible in Win 2000. [1] We had to make some magic, probably rewrite the program and use some weird device driver to write to the printer port (IIRC again). And multitasking messed the timing. At the end it worked, but upgrading the computer was not easy.
[1] If that makes no sense, replace that with a Win 3.1 to Win 95 transition, but I think it was not that old.