Hello, the question is this, I want to use a nxp microcontroller that works at 3.3v to handle (reception only) a ps2 pc keyboard that operates at 5v the issue is that the keyboard is open collector, and there are many circuits (all the same) on a bidirectional adapter, but since I do not need the bidirectional idas I was wondering if just connecting an external pullup resistor or using the internal one of the micro would not be enough, since without the own resistance the keyboard signals would matter a lot if I connect them to 3.3v?