No keyboard after ports update, 2x moused_enable="YES" culprit

perryh at perryh at
Mon May 16 05:25:46 UTC 2011

Daniel Staal <DStaal at> wrote:

> --As of May 15, 2011 8:03:29 PM -0700, perryh at is
> alleged to have said:
> > The AT and PS/2 keyboard interfaces are electrically identical
> > -- only the physical connector is different.
> --As for the rest, it is mine.
> The physical connector is all that actually needs to be different:
> Hot-swap interfaces make a point of connecting ground before power,
> usually be longer ground pins.

The PS/2 should qualify on this point, provided it is wired
_correctly_ (with the connector shell grounded both on the
motherboard and in the cable).  I'm less sure about the AT,
which used a 5-pin DIN plug that may not even have had a
shell-ground on the motherboard -- we were less concerned
about generating RFI in those days. IIRC all 5 pins were the
same length.

It's possible this particular Belkin keyboard used longer pins for
power and ground than for signal, so as to be safely hot-pluggable
even if the motherboard didn't ground the connector shell.  However,
I've since gotten by with hot-plugging a PS/2 trackball on the same
machine a couple of times, to clear lockups.

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