I purchased this keyboard adapter in order to use an old Hi-Tek RT-101+ DIN-5 PC-XT/AT keyboard with "space invader" style keys (gotta love them clickies!)  However, when I plugged the keyboard in and booted my PC, POST displayed an error message: "Keyboard/Interface error" "press F1 to continue".  I proceeded to troubleshoot using the various PS/2 to USB adapters that I had while wondering if I had received a defective product or if my keyboard was broken.  It turns out that there was a switch on the underside of my keyboard that lets it operate in either PC-XT mode or AT mode.  I flipped the switch to AT mode, and my computer was able to finish POST.