The scariest boot loader code

It shouldn’t be surprising that the HP-UX FAQ eventually grew an entry for “how can I make a 712 run headless”. It was possible, and to do it you had to change the firmware “console” path. The 712 firmware would not allow you to do this, to keep you locked to a keyboard and frame buffer console, but some of the HP-UX standalone tools could be used to change this without the firmware getting in the way, so the FAQ recipe was roughly “abort the boot sequence, at the BOOT_ADMIN> prompt, do not start the HP-UX kernel but some diagnostic tool, and then at the tools prompt, type a magic sequence without any mistake or you’ll be very, very, very sorry”.

There was no exaggeration in these words: the magic sequence is conspath 2/0/4.0x283, which is everything but intuitive and easy to remember.
↫ Miod Vallat

What a great story.