OMG! Trust me the ps2 sticks are analog. And yes, technically, they do need to be converted to digital to be processed by the PS2, but its not anything that you can hack (and it is not a 12-way stick). If you can't understand this, then don't even bother thinking about how to hack analog controls to Happs digital sticks. Its not something you are going to want to do anyway. As blueoakleyz stated, just hack the digital ps1 pad and you will be better off. If your intent in doing all this is to play 007 games on your arcade cabinet, then you will be sadly disapointed.
Wow, I feel better now.