Dunno if this is the place for this

Okay, I play Super Turbo on GGPO.

I know you have the option to select ‘Old’ Characters.

Chun Li’s input is Down Down Down Up.

I select her, and press the buttons straight away.

To my dismay, I am still ‘New’ Chun.

What am I doing wrong?

I believe you have to do this:
Select Chun-Li with Jab button
Input the code (Down x 3, Up + Jab Button)
It won’t work with any other button. You’ll hear her voice if you did it right.
Good luck!

This is what I’ve been doing wrong. Thanks.

Honestly, don’t even bother with doing the motion right. Just remember if you have to mash l,r or u,d and mash those directions while mashing jab.