Hi,

My Pegasos2 is not booting (no VGA signal coming from the VGA Card, no Openfirmware, no Bplan logo, my monitor's signal light turns to orange), when my external modem (3com USRobotics 56 Ext) is plugged into the serial port and turned on.

Why might this happen?

Guvenc

Wild guess:

The firmware sends out it's standard startup-message over serial.
It realizes that there is someone(thing) on the other end of the line.
It doesn't get the answer it expected (from a dumb terminal).
It sits there thinking "what the what the Ford was that ?"

Isn't serial debug an output only at that stage, though? If not are there any config options for it in the firmware?

Does the modem work ok when you switch it on after booting? I've had a shorted PS/2 port stopping a PC before (with errors off in bios), when physically removed all went fine.