Ok, I've got the problem system plugged in to boot it up. The OBP is version 2.4 (the working system is 2.9). Upon booting from the installation CD I get (my CD is set for ID 2) ok boot /sbus/esp/sd@2,0:c Boot device: /sbus/esp/sd@2,0:c File and args: >> NetBSD/sparc Secondary Boot, Revision 1.15 >> (builds%b6.netbsd.org@localhost, Sat Nov 6 18:30:47 UTC 2010) Booting netbsd Data Access Exception ok That's where it dies.I haven't had a chance to try a netboot yet, still need to set things up to do that.