Remapping lr-mame2003 in-game GUI (Tab/R-shoulder) to something else

[lockescow]

Earlier today, I was trying to remap the R shoulder button on an SNES controller for blocking button 2/6 on Mortal Kombat within the lr-mame2003 GUI (accessible via tab/R button in-game). Upon reassigning R as button 6, it somehow overwrote/removed the Tab key binding as well. In doing so, basically I overwrote the ability to bring up the in-game mame GUI again after closing.

Deleting all the .cfg in RetroPie/roms/arcade/mame2003/cfg/ (arcade is where the roms are) didn't reset anything. I ended up going into retropie setup, deleting mame2003, and then reinstalling it. Wasn't a big issue, but it took a bit of time trying everything else...

While Mortal Kombat only use 5 buttons, I'm thinking 6 button games will need that R shoulder button. Which got me into wondering if there is a way to reassign mame in-game GUI toggle to be hot-key with Select-R, or rebind it to some other key on the keyboard? If so, where would I find the file to modify? Unless that's already possible and I'm too blind to see it?

Raspberry Pi 3 b+ / RPie 4.4 / lr-mame2003 / roms in arcade folder

[dankcushions]

@lockescow the tab button is bound to R2, not R. i think the fundamental issue is that you have bound your R to R2 in initial controller setup.

in any case, you can rebind the tab button it in the 'tab' menu. it's called UI MENU or something like that.

[lockescow]

@dankcushions The thing is I don't even know how I overwrote that R2 binding in the first place. In that 'tab' menu, I simply made snes R button as 1p/2p #6. Maybe I'd edited an input field in there that I might have not read carefully. I'll take a look after work later in the tab menu to see if that's the case. One thing I remember though is that it was a "buttonX OR keyX" thing, and not a "buttonX AND keyX" so I'm guessing binding it to the select+ hotkey won't be doable. As long as I can rebind it to a keyboard and not relying on the controller, I'm good.

[lockescow]

So I've taken a second look at the 'tab' menu, and I'm not seeing any rebinding for the Tab/R2 GU toggle listed on there.

Here's the complete listing of all bindable things on that Mame GUI menu
P1 Up
P1 Down
P1 Left
P1 Right
P1 Button 1
P1 Button 2
P1 Button 3
P2 Up
P2 Down
P2 Left
P2 Right
P2 Button 1
P2 Button 2
P2 Button 3
Coin 1
Coin 2
1 Player Start
Tilt
Test
2 Player Start
Service 1
Coin 3
Coin 4
P2 Button 4
P2 Button 5
P2 Button 6
P1 Button 4
P1 Button 5
P1 Button 6
Return to Main Menu

I ended up rebinding P1 R2 within RetroArch Settings to my keyboard F10. I guess this will work for the time.

[dankcushions]

the problem was that your foundation was wrong i think.

my theory: during https://retropie.org.uk/docs/First-Installation/#configure-controllers you bound L bottom/R bottom to your L and R buttons. you should have bound L top and R top. this would probably mean that MK would have had sensible default controls (along with SF2, etc), and it would have also meant that you had no SNES button bound to the MAME menu (not that you should need access to it anyway).