After much initial confusion i was able to get Open Firmware running and
set the input and output devices using BootVars (I didn't set the
nvramrc as the model's page suggests, but i didn't have the problem of
low screen contrast). Open Firmware is very unstable and will freeze
after enough successful commands.

Open Firmware refuses to boot my NetBSD/macppc iso cd after this
command:
boot scsi-int/sd@3:0 NETBSD.MACPPC

So i gave up on the cd, and used the floppy and that seemed to work very
well. After the complete and total installation of NetBSD up until the
first restart (when it says "NetBSD Installation is complete, please
restart from your hard drive, edit rc.conf blah") from the actual hard
drive i get this message "/: Error partition full", something like that.
so i just exited single user mode, went back to the Install menu and
rebooted the system.

When i reboot and go back into Open Firmware i enter this command:
boot ata/ata-disk@0:0

it completely loads "stage2" but it freezes when the activity bar is
spinning at stops at a certain number, like this:

 >> NetBSD/macppc OpenFirmware Boot, Revision 1.3
 >> (tsubai@mint.iri.co.jp, Sun Nov 26 01:41:27 JST 2000)
309495 \

and it just says there. I retried the whole process, and same deal. So
I wondered if maybe my hard drive's MBR (err, zero partition space) is
corrupted (it's not the orginal). I doubt that though.

Any help would be largely appreciated. Just to remind all, i have read through
the docs thoroughly. If anyone has had the PowerMac 6500 (performa-type)
i would appreciate it if you shared your experiences. Thanks a lot!
-rian