Hi

I tried to set up netbsd a few months ago, but I came up against a brick
wall in that my 5500/250's screen wouldn't initialise, and I had to use
a serial console to do anything, which wasn't terribly useful.
However, I finally stumbled upon the relavant linuxppc mailing list post
I had been searching for that tells how to enable the screen on the
5500.
it's at http://lppcfom.sourceforge.net/fom-serve/cache/381.html
the second post says
---
To set your monitor to always turn on when you boot to Open Firmware:

Reboot.
Cmd-Option-O-F during the chimes
(Where CR is return and you DO NOT type quotes.)

Enter `nvedit CR', hit Ctrl-N a few times and type:
cpoke 0a7 0f3000032CR
cpoke 093 0f3000033CR
cpoke 03e 0f300003aCR
Ctrl-C
nvstoreCR
setenv use-nvramrc? trueCR

Upon future reboots, the code to turn on your monitor will get run
automatically.

-- Colin Dellow
---
and lo, behold, after setting the nv ram patches in place, and changing
the output device to /bandit/ATY,264GT-B and input-device to kbd, the
familiar black-on-white OF screen came up!
I've yet to try setting up netbsd, however I imagine it should go
smoothly now.
Just thought you might like to add this information to the
http://www.netbsd.org/Ports/macppc/models.html model support page for
other people in the same predicament.
Cheers

Blair Harrison