Interfacing one keyboard to two computers?

[bizzybody]

This is a bit off the arcade path (though MAME could run on the finished product)...

I have an old Tandy 1000 HX computer, 8088 CPU. Its keyboard is a matrix style with a pair of real wire ribbon cables connected to the main board. I've had it apart, the Tandy keyboard has no electronics on it, the matrix output goes directly to the main computer board.

Now for the hack part. When (if ever) those 12cm by 12cm 'nano' ITX PC boards are available, the expansion bay of the Tandy would need very minimal modification to contain one. I'd cut holes for the ITX's ports in the Tandy expansion bay cover, or maybe stealth it by recessing it and modding the original cover for quick removal. (Plenty of room under the keyboard for a 2.5" hard drive.)

What'd be ultra cool is to have BOTH the Tandy and the NITX PC systems functional, with a switch that swaps power and the keyboard between them.

I figured that since there are several devices used for connecting arcade controls up as 'keyboards' for MAME cabinets, there ought to be one that can connect a keyboard up as an AT, PS/2, or USB keyboard? I assume the really tricky bit would be the switchover?

The looks on people's faces when I boot up Windows XP on a "Tandy 1000" would be worth doing this hack.