I've followed the guide for the piggyback install method here
http://www.mmmonkey.co.uk/sega-dreamcas ... free-bios/
Unfortunately, I have a Va2 console and the portion for the wiring of the switch says to solder the middle connector of the switch to D501.
The problem is that D501 doesn't exist on the DC.
Where do I solder this switch to on a VA2!?! I've scoured the internet and I just can't seem to find any info on it.