[rescue] Serial console on IBM RS/6000 250?

Carl R. Friend crfriend at rcn.com
Sat Feb 21 07:42:22 CST 2004

   On Fri, 20 Feb 2004, Todd Carson wrote:

> I recently picked up an IBM RS/6000 250 that I'm interested in
> using to try and gain some familiarity with AIX.


> However, I have no experience with IBM workstations, and I can't
> seem to get the system working with a serial console. It seems to
> boot into AIX successfully (based on LED and hard drive activity),
> but I can't get any output to the serial console.

   Do you see anything if you plug a monitor into the framebuffer?

> I'm using a null modem adapter and cable that have worked fine
> with Suns, HPs, and DECstations; my settings are 96008N1. I've
> tried using both serial ports on the machine ("S1" and "S2"),
> and also removing the framebuffer.

   The RS/6000 assigns the console at initial load time, or a
subsequent reconfiguration.  It won't reassign on the fly.  You'll
need to put the thing in Service Mode and boot from the installation
media (or a mksysb backup) to reassign it.

> The lock is in the "normal" position, and I don't have the key.

   Oh, my.  I'm not going to say, "You're done for", but things
don't look terribly good at this point.  Can you get the lid off
the thing without completely mangling it?  If so, you should be
able to jumper around the lockswitch to put the machine into
service mode.

> I saw a mention in the list archives of a serial cable with a
> different pinout; is this what I need, or is there something else
> I'm missing?

   The latter.  A key.

| Carl Richard Friend (UNIX Sysadmin)            | West Boylston       |
| Minicomputer Collector / Enthusiast            | Massachusetts, USA  |
| mailto:crfriend at rcn.com                        +---------------------+
| http://users.rcn.com/crfriend/museum           | ICBM: 42:22N 71:47W |

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