Wiring a Service Switch in a MAME Cabinet?

[Necro]

I'd like to use the Service Switch in my cabinet so that it functions in MAME.  I'm thinking having it just wired up to an IPAC or MAME won't work since it's not a momentary button and it will cause some issues.  I'm thinking I'd need it to register the keypress, then resend the keypress on 'release' or when the switch is turned off service mode.

Anyone done this or have any ideas?

[u_rebelscum]

Well... a few issues.

Different games had different Service Switches.  AFAIK, most were on/off switches like you're talking about, but a few were momentary switches (I doubt any were pulse, or pulse on change like you want to do).  Mame most likely is set up to emulate the original switch type, so if the game had one like you have, mame expects the button to remain closed.  Ipac and mame can handle continuously closed buttons.  The times you might run into problems with just wiring your switch is if it's closed (on/"pressed") when the computer boots, and when you're outside of mame (say trying to post at this forummmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm ).

I'm sure it's a pretty easy (and standard) circuit to pulse when changed, but you don't need to.

[Necro]

I'll have to check that (the test mode hold vs. momentary thing).  As it does present a bit of an issue I wasn't expecting.  And understood on the hold down the key thing .

And the actual wiring up of a switch wasn't my main concern, it was if I were to hook one up how would MAME react and would I need some kind of circuit/program setup to pass the proper input to MAME so it functioned as the switch actually should.

[CrazyKongFan]

My cab had a SPDT switch on the coin door when I got, one side was momentary, one wasn't. I replaced it with one of the same size that had both momentary, then wired it up to F2 and F3 on my encoder (F2=service, F3=reset in MAME). Seems to work for all the games I've used it on so far. The ones it doesn't work for is one that needs 3 buttons (some Williams games). Those had a little bracket with 3 momentary push buttons (In MAME, it uses F1 also...I think I just mapped it to one of the control panel buttons, since it doesn't do anything outside of service mode)