> PS/2 to USB adapters floating around in a tackle box.
Heh. [Most] PS/2 to USB adapters aren't.
They don't actually adapt the PS/2 protocol to USB, they just adapt the pins. The USB _hardware_ on the host does the emulation. However, the new generations of USB chips stopped bothering with the PS/2 emulation so these adapters are now useless.
Actually it's the device that supports both PS/2 and USB mode. The host doesn't.
Sure. It is also a possibility, but a lot of PS/2 devices predate the USB.
This is also my understanding too
Wonder if this is part of why my unicomp keyboards don't work for going into the bios on my current desktop, it doesn't work until inside the OS.
Damn, in that case I'm certain that the ones I have gathering dust, all of which came from various packaged mice/keyboards, won't be up to the task. I've got enough old hardware they might still come in handy one day, but I'm pretty sure they're now just relics.
You can buy real PS/2 to USB adapters. E.g. this one from StarTech: https://www.amazon.com/dp/B00028OP2Y
I bought a used slideable rack-mounted LCD last year for my home server rack, and its keyboard with touchpad use PS/2. That's how I found that out.