The problem turned out to be a of lack of patience!
During the patch installation start-up you are prompted to enter your name 
and then prompted (with a ":") to enter a text message.  You terminate the 
text by a period ".".
Well, I had no text I wanted to enter, so I immediately typed a "." after 
the colon prompt.  And nothing (appeared) to be happening.  So, on the 
blank line, I entered another ".".  Then something happened! - panic, from 
/var/adm/crash/ crash-data:
cpu_panicstr = 0xfffffc000052f818 = "thread_block: interrupt level call"
I tried this several times - each with the same result.
Finally, I showed a colleague what I had been doing and he suggested 
waiting after entering the first period.
Things worked just fine!
Thanks to those who responded:
John Speno
Alan Davis
Dr. Thomas P. Blinn
Yaacov Fenster
Thanks,
Jim Eiler
Received on Mon Feb 15 1999 - 16:11:09 NZDT