Hardware hacking guru Joe Grand of GrandIdeastudio has posted this new, detailed introduction/demonstration of the JTAGulator, an open source hardware tool te hat assists in identifying on-chip debug (OCD) and/or programming connections from test points, vias, or component pads on a target device.
(We note the Bus Pirate usage at 5:40.)
These bloody JTAGulator boards are $160 bucks a-pop!