First post, by keenerb
http://www.hagstromelectronics.com/products/ke18atxt.html
Connects in line from your PS/2 keyboard to the target computer's XT keyboard port.
Powered from the computer's keyboard port, no external power required
Translates the PS/2 keystrokes into their XT keystroke equivalents
Allows use of PS/2 style keyboards with XT type PCs and other XT based computers such as CNC machines
Includes a 5 pin DIN to 6 pin miniDIN adapter and cable to attach to the computer's keyboard port
Uses standard drivers, no special drivers needed
I know there's a hobby board available for an AT to XT adapter you can put together for about half the price but this looks pretty convenient.