i've peeled the outer insulation off the serial cable.
   I had labeled it with duct tape that it was broken. I had freed it
   enough to peel by just pulling, and when I got to the duct tape the
   insulation broke instead of the duct tape ripping. it's interesting
   this duct tape was stronger than this thick insulation.
   inside, the wires for each pin are wrapped in a braided ground wire.