[rescue] RS6k serial console tips?

Jonathan C. Patschke jp at celestrion.net
Fri Apr 9 12:26:11 CDT 2004

On Thu, 8 Apr 2004, Todd Carson wrote:

> From what I've read, I know that I can't select the graphics console
> here without an original IBM keyboard, which I don't have.

I seem to recall using an SGI keyboard on at least one of mine, but all
the ones I use day-in, day-out have IBM Model M keyboard on them.  I
-think- the machine with the SGI keyboard was my 250.

> I was under the impression, though, that I could select a serial
> console at this point.

If you're plugged into the first serial port (don't accidentally plug
into the T port, like I did the first time) with a true null-modem
cable, and are listening at 9600,8,N,1, you should see a little bit of
IBM copyright notice, followed by the "Please Define the System Console"

> If I have a keyboard (a standard PC PS/2 keyboard, DEC-branded)
> plugged in, then the system will hang at LED c31 with no output to
> either the monitor or other machines connected to S1 or S2. Input to
> either the keyboard or the remote terminal emulators has no effect.

That's really, really odd.  What sort of monitor do you have plugged
into the system, and what sort of cable are you using?

> If the keyboard is not plugged in, then the "Select the system
> console" prompt is displayed on the monitor,


> but still nothing is output to either serial port S1 or S2, and typing
> things in from a serial connection "blind" doesn't accomplish anything.

That ain't right.  Something is FUBAR.  Try booting the machine in
service mode WITHOUT a CD in there.  You should get the offline
diagnostics.  Play around in there and see if you can get it to do
something useful.

> The first few times I tried using a serial console, the machine would
> drop to the KDB prompt if I hit the reset button while it was sitting
> at LED c31, and I could use the kernel debugger over the serial line.

Okay, so the hardware is working fine, it looks like.

> Since I don't have the right cable to connect the RS/6000 to my U10
> sitting right beneath it, I'm using a Mac Classic with Kermit.
> They're connected with a Sun-branded DB-25 to MiniDIN-8 cable ande
> a Radio Shack "null modem adapter".

That is -exactly- what I'm using to connect my 250 to my Indigo2, so
that's a known-working cable configuration.

> I'm assuming the cable and terminal settings (9600 8N1, DTR handshaking)

Don't use handshaking, if at all possible.

Jonathan Patschke  ) "Being on the Internet is not the same as being
Elgin, TX         (   famous.  That's like calling Cheetos 'dinner'."
USA                )                                    --Metal Steve

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