How does KDQUEMODE work? (This time for sure!)

[Peter M. Jansson]

I'm trying to port Tom Roell's X11R4 server to our Intel Unix SysVr3.2
systems, and I'm having some trouble getting asynchronous input from
the keyboard.  Although I can think of a solution involving a fork,
and a stream pipe, I notice in my manual entry for DISPLAY(4) (a perfectly
obvious place to put information about the keyboard, I thought) the
following:

	[in the section on ioctl's]

	KDQUEMODE
		Enable/Disable special queue mode. [blah, blah, blah].
		The structure "kd_quemode" is as follows:

This implies that the DISPLAY driver has a means of allowing the mouse and
keyboard to collect input into a queue and generate a signal when the queue
is non-empty.  Unfortunately, I can't find any other documentation for this
mode.  I was hoping some kind soul can answer a few questions:

	1. What is the structure of the queue pointed to by the
		pointer in the hd_quemode structure?  What is
		the initial state of the queue (head/tail)?  How
		is the queue accessed?  How does the driver
		synchronize with an application reading stuff?

	2. How is a mouse hooked in to this?  What kind of mouse? 
		If it is a bus mouse, from where is the driver
		available?

	3. In a simple test, I enabled this mode and then waited for
		either a signal or a read.  Neither completes,
		no matter what I do to the keyboard.  How do I get
		it to work?  Are other ioctl's required?

I will appreciate any help.  Replies by mail are encouraged.

Thanks,
	Pete.