On 27-08-17 21:04, karl@??? wrote:
>
> 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
>
> -----------------------------------------------------------------------
> Aspö Data
> Lilla Aspö 148
> S-742 94 Östhammar
> Sweden
> +46 173 140 57
>
>
I can admit that: a friend of mine cannot part of his original IBM AT
keyboard. So it has a converter from big DIN to PS2 to usb to connect it
to his PC without PS2 ports.

Grtz.

Nick