I have just tried to install NetBSD on a 386 PC we have kicking around our 
office. The boot code prints the usual stuff as my 386BSD machine does 
(using the mach boot). The difference is that the machine hangs and won't 
accept any keyboard input.

Looking through the code I would suspect that the problem lies in the A20
handling code. So I have three questions:

1) Not being amazingly familiar with the PC architecture what is the A20
	code supposed to do and why. Why is it linked to the keyboard
	programming?

2) Why is the A20 code very different between the Jolitz' original boot 
	code and the mach derivative that we're currently using.

3) How do I overcome the problem.

As a caveat to all of this the machine in question is a Zenith 386 with 
ESDI disks. It has run 386BSD using the old boot code. On a similar note 
I have a PC at home running 386BSD with the new boot code (the old doesn't 
work)

Any ideas?

		Cheers,
		  Alex.

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