On Oct 5, 10:02am, Greg A. Woods wrote:
} 
} That's because it uses completely upside-down and inside-out logic.  The
} correct test is not to see if there's a serial port connected (quite the
} contrary since there might not actually be anything connected at boot
} time, or if it is it might not be powered up or whatever), but rather to
} test if a PC keyboard is connected.  For the most part it seems almost
} all Suns have been using the lack of a keyboard to default back to the
} serial console (even if the EEPROM says to use the keyboard) and there
} have been far fewer problems with this scheme.

     As other people have said, this can also be tricky to get right on
a PC.  I installed FreeBSD on one box, which had an IBM 3278 style
keyboard attached to it (i.e. the keys and layout were very similar to
what you would find on an IBM 3278 terminal, but it was designed for
use with PC's).  Anyways, there must have been something quirky about
the keyboard, since the bootblocks didn't detect it, and they
automatically switched to serial console mode.  The only output I saw
was a "version" line, after which the drive kept whirring but I wasn't
able to do anything.  Since I had never installed FreeBSD before, this
required a bit of head scratching before I figured out that I should
replace the keyboard.  If an auto switching scheme is implemented, it
should print a message indicating that it is switching to serial
console mode, as a safety precautiion against this situation.

}-- End of excerpt from Greg A. Woods