IPAC-like Shift key behavior in Mame?

[ckas2]

Hi all,

So sorry for the noob question... please go easy on me

Does anyone know of an existing way to make MAME treat shift keys like the IPAC / JPAC does?  I want the shift key to only emit its own function upon release and only if it wasn't ever used to shift another key. For the record, the NOT functionality does NOT actually solve this!

GaryMcT asked this question many moons ago here http://forum.arcadecontrols.com/index.php?topic=95305.0 but it was never actually wrapped up!! He was apparently going to write something for MAME over a decade ago but I can't find anything on this anywhere!

Does anyone know if such a solution exists?

I've been using an old J-PAC forever in my arcade, it recently failed and now I am using a JAMMA to dual joystick setup in my cab but am very used to the additional functionality of the JPAC which I no longer have!!

thanks!