I checked the website and tried to understand their random instructions. I have a TP 601c charger and need some help updating the firmware. Mostly I don't get which six pin connector I need. If someone has experience updating these chargers, would you help me out? Thanks.

You need to buy the little PGM-V2 usb programmer... comes with two cables, the usb adapter, and a resistor. Have a 9 volt battery handy, you need it foe the update. If you can't find the programmer F/S anywhere let me know, I may still have one here somewhere (new price was $20-30, I think.) It's a little fiddly doing the update, but does work fine.