From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Tue, 21 Nov 1995 09:09:05 -0500
From: forsyth@plan9.cs.york.ac.uk forsyth@plan9.cs.york.ac.uk
Subject: locked keyboard
Topicbox-Message-UUID: 354b6a12-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19951121140905.47ILh1DcT8YfEsNDDuAq4uO0bVBVxVJ2JZVxHR1L8rw@z>

i've checked the IBM PC/AT handbook.
on a machine with a keyboard controller
compatible with that specification,
both bits 5 and 6, not just bit 6, change
the keyboard's handling of scan codes.
the other option looks like a PC/XT compatibility mode to me.

perhaps the mouse enable/disable appeared in the PS/2
where they'd done away with PC/XT compatibility?
i suppose there must be a bit somewhere to tell
the difference, but we haven't got a PS/2 handbook here.

oh god i hate this stuff.