to tell you you should use an approach you don't want to use.

If you want to do things the hard way, then go ahead, but don't use economics or level of effort as an excuse, because it's cheaper to do it the right way.

However, your arguments are fallacious, so far. You can drive this cable directly from your MCU, as it's open-drain, a hookup requiring, at most, a few resistors and, maybe, a diode or two.

You are free to do whatever you want, but all the PS/2 wedge interface requires in a one-off is wire.

What's more, if you are using a PC, you can probably patch into the interrupt handlers for the mouse and get the information you want when you want it without any wiring at all.

I'd recommend you, at least, read the spec's.

RE