NetBSD 9.2 on Quadra 800 emulated by QEMU

Hi all,

I'm attempting to run NetBSD 9.2 on the Quadra 800 as emulated by QEMU.
However, I run into a snag when installing using the traditional
method from inside Mac OS 8. This snag is related to the /dev/constyy
device which is not created. It is, however, referred to in the
/etc/ttys file and subsequently boot after installation halts when it
cannot find the device.

I my various installation attempts I've seen the /dev/constty file
being created just once, so I'm wondering whether there is a
particular combination of kernel and sets that I should install so it
gets created when I run make devices from the installer? Or is there
some other issue preventing the creation of the device?

Thanks,
Howard