Does anyone know of an easy way to interface an A500 (internal) keyboard with a pc motherboard - either ps2 or usb?
The easiest way I can think of is a single-slot PCI riser card for the Via Epia (to get PCI slot vertical) and then
Catweasel MK3 PCI card. Catweasel MK3 has Amiga keyboard connector and
windows drivers for keyboard.
You can
hack the standard keyboard connector to A500 keyboard, you just need to wire correct signals from the A500 keyboard circuit board to the connector (aminet tower conversion hacks in hard/hack have detailed info about this).
So, granted the mobo + riser + catweasel fit height-wise, you should be able to use original A500 keyboard.
Hairy, and certainly needs some planning, but should work.
Also, as a bonus, you could use the original A500 floppy drive and read/write amiga disks. :-)