If you read my earlier post, you see I had a problem getting my new Quasicon controller to work with Mame.. well, as it turns out, you can configure MAME to work any way you want!
Now, I'm sure lots of people know this, but I couldn't find it online anywhere, so here's how you do it. I figured I'd put it as a new post on the front page so if people were looking for this answer they could find it.
Go to Options and select "Default Game Options" - go to "Controllers" and click "Enable Joystick Input" to make sure your joystick is turned on. Hit apply and then OK.
THEN.. Open up a game, get it going by following the prompts, then hit TAB. A menu comes up. select "Input Options (General)" - go to Player 1 (or 2 if you want) input, and you will see a list of commands like UP, and BUTTON 1.
Select (for instance) "up", hit enter, and then the default thing that makes you go "up" in the game goes blank. Hit what you WANT to make you go up (in my case, "UP" on the digital Joystick) and it should display.. you can do this for all directions - then you can decide which buttons you want to do what. - then repeat for player 2
Once you do that, escape out back to the second menu and you can go to Other input options and select what buttons you want to be "insert coin" and "start player 1".
After that, you can configure per game by going to the game, hitting TAB and going to Input options (game) - so the button configuration is how you like.
Thanks to Chris from Quasimoto.com for teching me how to do this!!