Alessandro:
> On Sun, 27 Aug 2017 at 18:03:08 +0100
> Simon Hobson <linux@???> wrote:
> [...]
> > AFAIK the underlying protocol for the keyboard is the same (or near enough
> > for simple conversion) between the two connector formats to allow for easy
> > conversion between plugs.
>
> They are, adaptors are purely mechanical.

PC/AT and PS/2 have the same protocol and electrical spec. except they
have different connectors. The protocol is bidirectional.

PC/XT has the same pinout and connector as PC/AT but not the
same protocol and they won't work together.
The protocol is keyboard -> pc only.

See page 16 of
http://kbdbabel.sourceforge.net/doc/kbdbabel-vortrag-vcfe80-20070429.pdf
and
https://en.wikipedia.org/wiki/IBM_PC_keyboard
for details.

Regards,
/Karl Hammar

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