[danjovic] has you covered with the open-source EXPS/2 keyboard adapter. It will allow you to connect either a PS/2 keyboard or a USB keyboard in fallback mode to the Expert using an ATMega328P ...

[Matt] built an AT2XT keyboard adapter on a prototype board using an AT to PS/2 keyboard cable. An AT2XT keyboard adapter basically allows users to attach AT keyboards to XT class computers ...

Arduino enthusiast Evan Kale has been the inspiration for a new Arduino powered Bluetooth adapter which has been created by DastardlyLabs to allow those interested to make their USB keyboards ...

I need to get some PS2 extension cables, and it looks like a Y-cable + 1 extension cable will be cheaper. Will this work?