I downloaded 200206060000/sparc64 from releng and wrote the
miniroot.fs to /dev/rsd0b (not used by netbsd even), halted and
booted, and got:

# gzcat < miniroot.fs.gz | dd bs=4k of=/dev/rsd0b conv=sync                   
 
1792+0 records in
1792+0 records out
7340032 bytes transferred in 25.868 secs (283749 bytes/sec)
# cd /
# halt
..
syncing disks... 12 12 7 done
halted

Program terminated
ok boot disk:b netbsd -s
Resetting ... 

screen not found.
Can't open input device.
Keyboard not present.  Using ttya for input and output.

Sun Ultra 1 SBus (UltraSPARC 167MHz), No Keyboard
OpenBoot 3.11, 256 MB memory installed, Serial #8438477.
Ethernet address 8:0:20:80:c2:cd, Host ID: 8080c2cd.



Rebooting with command: boot disk:b netbsd -s                         
Boot device: /sbus/espdma@e,8400000/esp@e,8800000/sd@0,0:b  File and args: net
bsd -s
NetBSD IEEE 1275 Bootblock
.
Fast Data Access MMU Miss
ok 


The system is currently running 1.5ZC.

Thanks
--sjg