For a while I've had an old PS/2 Model 70-E61 (with an MCA bus, 2Mb RAM
and 60Mb ESDI disk) lying on the floor of my office here, and for a
while, I've wondered how hard it would be to get NetBSD running on it
(more as an exercise than with any practical end in mind - even if I
did have some PS/2 SIMMs, I haven't got the key to unlock the case 8-().

Well, now I know! I've patched the NetBSD kernel (1.1 pl1) to cope to
some extent with (most of) the idiosyncracies of MCA PS/2s, and added
an "mca" root device modelled on the existing "pci" root device.

So far, I can get my PS/2 booting to single user mode off a floppy and
detecting all the MCA devices installed (the ESDI controller and a
3C523 Ethernet card). I'm getting a lot of floppy seek errors, but that
may be due in part to elderly hardware. Next on the to-do list is a
hacked version of the "ie" driver for the 3C523 and some sort of driver
for the ESDI controller.

If you're interested, check out
http://www.epcc.ed.ac.uk/~st/netbsd-mca.html or
ftp://ftp.epcc.ed.ac.uk/pub/st/netbsd/netbsd-mca-1.0.tar.gz

If anybody wants to port this to other BSDs, feel free.

-- 
Scott Telford, Edinburgh Parallel Computing Centre,       <s.telford@ed.ac.uk>
University of Edinburgh, Mayfield Rd, Edinburgh EH9 3JZ, UK.(+44 131 650 5978)
"Is it a virus, a drug, or a religion?"  "What's the difference?" - Snow Crash