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.
The internal OCD port uses an electrical standard known as JTAG/COP. The signals have to be buffered to protect the hardware from damage and we use a JTAG wiggler to do this.
Those with some electrical experience could build their own circuit, but most will opt for ordering one.
Schematics and Software to build your own
Commercial The Wiggler seems to be the cheapest at $150.
Hobby Could the 20-pin ARM-JTAG be modified to work with Kuro-Box? $20.
Locate the pads
The pads are labelled CN5:
In order to use this port, you should add the 10K series VIO resistor R67 and a 4-way 1K resistor pack at RA11. It may be possible to use some functionality without these components.
If you know which set of pin-outs that LinkStation/Kuro-Box uses, please update this page with the details. According to Baulab the following pins are identified
The same page also contains the schematics and some picture of the jtag cable. This cable can be used without adding the additional components.