SUMMARY: System in boot mode when console power off

From: Per Akesson (
Date: Mon Apr 20 1998 - 05:59:30 CDT

Here is a summary of my original question:

>this morning I noticed that my server was in boot prom mode, after
>my VT100 console had stopped working, just as if I had sent a BREAK.
>Is there some way to configure the serial connection to
>prevent this ?

And here are the replies I received. thank you all for your help.

From: "Roy S. Rapoport":

The way we've gotten around it here is by using a console server.
Basically, it's a Sparc 2 with an add-on card that gives it 64
additional serial ports. The company ( makes a
console server model of that that doesn't halt your machines when
the CS Sparc goes down.

From: Jochen Bern :

Yes and no ... you could have the serial Cable mangled such that the
SUN will always see DTR no Matter what State the VT100 is *really* in.
No Way to disable it in Software, Firmware or EEPROM Setup that I know
of ...

From: Ameet Chaubal

If you have a e3000, e4000, e5000 or upper
turn the key switch to secure mode

From: Rik Schneider

This is not uncommon Sun's Serial code apparently interprets noise (from
powrering down the teminal) on
the serial line as a <BR>.

From: Gert Marais

You do not specify what type of machine you have but on the SC1000&2000
and enterprise machines which a key present turn the key into save mode.

That is when you turn it to far right (off on diag save). When key
position is turned into save mode a message on console should display
something like Key turned into save...... After this you can swith the
console off, remove the cable whatever you like. Remember if you make
use of power-off command on OBP you must move the key out of save mode.

From: Eddy Fafard

Been there and tried everything to no avail. Rumor and theory is that
if you wire it like this it will work but I tried with no luck. I posted
a few
mounths ago and got no real answer either. Good luck and let me know if
you get a real fix, or just post.

2 Tx ------------------------- ------------------------- 2 Tx
   3 Rx ------+------------------ ------------------------- 3 Rx
                Z 4.7K resistor
  25 -5v ------+ 25 -5v

   7 GND ---------------------------------------------------- 7 GND

   4 RTS --+ 4 RTS
   5 CTS --+ 5 CTS

   6 DSR --+ 6 DSR
  20 DTR --+ 20 DTR

  Per Åkesson
  Carmenta AB

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