I think I've read every thread on real knockers, and just need confirmation of the impossible...
Have a Stern High Roller Casino, that I've tried to add a real knocker to, using the Q24 coin meter connection.
(basically used this setup - http://www.home.earthlink.net/~pinball_stuff/knocker.htm )

It works in diagnostics, coil test or Q24 perfectly. (nice & loud too!)
But I cannot find anywhere in HRC's menus to set the coin meter Q24 for knocker/credit function.

From reading this virtual pin forum thread:
http://vpuniverse.com/forums/topic/830-stern-knocker-rom-tipfix/

...it looks like there are several Whitestar games including HRC that can't be programmed for a knocker.
Austin Powers
High Roller Casino
Monopoly
Roller Coaster Tycoon
Playboy

Can anyone confirm they have a working real knocker on any of the above machines... and if so, how?

Andrew... thanks. I was figuring that was going to be the case. (that was one thread Google search missed)

I'd hoped maybe it might be undocumented/buried somewhere in the menus of the last 3.00 ROM's.
But if Keith Johnson says it ain't there... I guess he'd know.

Oh well... saves me from buying more parts and I'll just modify as needed & move it over to my Tron instead.

Thanks again,
Greg

Small follow-up... before I removed everything, I confirmed that it all worked as designed, as far as the programming would take it.
I took the HRC off Free Play, and whenever I dropped a quarter thru a coin slot, the knocker sounded perfectly. LOL
Shame it can't re-program the Coin Meter setting to be for awarding Credits instead.
Such as life.