Add Jtag Port
From NAS-Central Buffalo - The Linkstation Wiki
This document is a work in progress. It explains how to fit the internal on-chip debug (OCD) port on a Linkstation, Kuro-Box or Kuro-Box/HG to a PC interface.
Adding the JTAG Port
Locate the pads
The pads are labelled CN5 and can be seen just above the serial level converter (where the yellow, orange, and red wires start to split) in this photo
In order to use this port, you should bridge R67.
According to http://www.abatron.ch/Files/ManAccessCOP-2000C.pdf and http://www.freescale.com/files/soft_dev_tools/doc/user_guide/CWH-UTP-UG.pdf the following pins are used for a PPC COP/JTAG interface: