Hacking the Xbox

128
Hacking the Xbox: An Introduction to Reverse Engineering
Figure 8-5: HyperTransport tap board mounted on the Xbox motherboard.
the board in place and will be removed, so it does not matter if the wire
bridges multiple traces. Once the wire was attached, I carefully adjusted
the position of the tap board on the motherboard, heating the wire to
release its bond to avoid lifting any of the copper traces. (I used a
microscope to aid in determining the optimal alignment.) Once I was
satisfied with the position of the board, I applied a strong epoxy to the
board joint to hold it all in place. The epoxy should cure and form a
rigid, stiff joint. (Note that some epoxies when applied incorrectly cure
into a gel; this is not acceptable, as the entire mechanical integrity of the
joint must come from the epoxy and not the solder joints.) I used Miller-
Stephenson Epoxy formula 907, and it sets with enough strength for me
to lift the Xbox by the tap board and not disturb the tap connection.
Once the epoxy had cured, I removed the temporary tack wire that was
used to hold the tap board in place, and cleaned the bare mated traces
with a bit of solderwick and flux. The last step of soldering the tap board
traces to the bare motherboard traces was now no different from
soldering any surface mount component onto a board; most of the
standard techniques described in Appendix B applied directly to this
situation. Figure 8-5 shows what the finished assembly looks like.
Building the Data Logger
The second challenge of eavesdropping the HyperTransport bus is
acquiring or building a logging device that can keep up with the 400 MB/
s data rate of the bus. Considering my budget, I decided that my only
option was to build a logger, as buying any tools with sufficient performance
for this job was well outside of my budget.