Connecting a Vectrex to an analog thumbstick...

[Jess Ragan]

http://www.instructables.com/id/Modify-PSX-Controller-for-Vectrex-Games-Console/step5/Modifying-2/

 

I'm a little mystified by this how to guide. Some of the steps are in painstaking detail, while others are frustratingly vague. The writer of the guide was able to turn a Playstation-like joypad into a Vectrex controller, but he doesn't explain specifically how to connect an analog thumbstick to the machine. He mentions putting 3K resistors on the "tracks" of the thumbstick, but which ones? There are three pins for each axis, after all. For that matter, which pins on the Vectrex controller port do you connect them to? Thanks in advance for any help you can provide.