@Istinto81
Nothing at all.

Mitu gave you the proper response with links.

on arcade games in its intended resolution there is black bars at top and bottom because its on 1280x1024 when I try drop the resolution lower on launch options the game wont load up for some reason, just the sound and a black screen.

I can go into option during the game with the 1280x1024 and change the screen to fit but I have to do that for all games it's a bit annoying.

Retropie 4.6 on a raspberry pi 3B with a 128gb Card.

@cder Well after playing around with it (and with your advice) I finally got Advance Mame working how it should. I haven't got a clue on how I managed it but i'm just happy that it is.

Thanks again for you advice and help.

@lycros Sadly, I had to put them in all manually. Im sure you figured that out by now.

I could have sworn overlays were in the docs but perhaps not:

may be a good addition to this page:

https://retropie.org.uk/docs/Shaders-and-Smoothing/

or do we want it on a separate page. paging @dankcushions what do you think?