NOTE: I submitted this post as a hint on macosxhints.com, You might check this link for any user comments.

Enabling serial console with panther is very easy. If you know where to look.

<br /> /System/Library/StartupItems/SerialTerminalSupport/SerialTerminalSupport<br />

Read this file. It has lots of information about the serial port.

After reading it, enter:
<br /> /System/Library/StartupItems/SerialTerminalSupport/SerialTerminalSupport start<br />

This should enable console access. However not in my case. I have to connect through a console server at my colo, which operates at 9600. Apple enables a 57600 baudrate by default.
<br /> vi /etc/ttys<br />

Look for the following line:
<br /> tty.serial "/usr/libexec/getty serial.57600" vt100 on secure<br />
And change this to
<br /> tty.serial "/usr/libexec/getty serial.9600" vt100 on secure<br />

give a
<br /> /System/Library/StartupItems/SerialTerminalSupport/SerialTerminalSupport restart<br />

And I was able to connect.

If I had discovered the above earlier, I had saved myself for driving to my CoLo serverroom a couple weeks ago when I made a mistake with remotly configuring my en0.