Just to clear up some confusion:
Amiga2000/3000/4000T use a DIN connector, A4000D/CDTV(?) use the small PS/2 style connector. Signal wise they are all pretty much the same.
PS/2-keyboards are just AT-keyboards that use the smaller connector.
No simple PS/2-DIN adaptor will allow you to connect any Amiga-KBD to a PC or otherwise !!
Your options:
- get the kbd-adaptor that came with some Micronic towers, it will convert the A1200KBD to PS/2 and than at the mobo convert any PS/2-kbd back to the A1200. It also said to be able to recognize a A4000-kbd used instead of a PS/2 one.
- use one of the hacks on Aminet to convert a Ax000 kbd for A1200 use, this works by disabling the kbd-controller on the 1200 and wiring the Ax000-kbd in it's place (Ax000/A500 include the controller in the kbd, A600/1200 on mobo)
- get a ready made PS/2 kbd converter for the A1200, these come in 2 variants. Either they are plugged into the foil-cable-connector or clipped over the kbd-controller (disabling it it similar to those hacks mentioned above).