USB stick error message

[Bob Bernstein <poobah%ruptured-duck.com@localhost>]

I put the USB stick that has been booting my NUC -- equipped 
with current 9.99.88 -- into my old eMachine, hit F12 when the 
eMachine logo appeared, and was presented a boot-device 
selector screen that correctly identified the stick. Choosing it 
I was soon at a halt with these three lines displayed:

--snip--

fn: diskn
1: NetBSD
Error 3

--snip--

Can anyone translate? Should I post in current-users?

Thank you.

--
A person of great honour in Ireland (who was pleased to stoop 
so low as to look into my mind) used to tell me that my mind was 
like a conjured spirit, that would do mischief if I did not give 
it employment.
                                Jonathan Swift