Does anyone have any experience with these motherboards? They seem to have a 486 socket (not sure whether socket 1, 2, or 3 at this point), along with a 386DX soldered on the board. I guess the idea was you could buy a cheap 386 and upgrade it to a 486 later.

I'm having trouble finding good information. I'm specifically trying to determine whether the CPU can be selected via a jumper, or if the 486 is always used if installed. I'm trying to find out what bus speeds are available as well. If it works the way I hope, it might be an easy way to scale from a 25MHz 386 to a 100MHz 486 in one machine.