@Texacate link updated in my post above.

I know this is SUPER old, but after parsing through possible ways/threads to get a trackball working on MAME2003, I was finally successful (after 3 attempts where I gave up and just went with advancemame)

A) in retroarch-core-options.cfg, add:

mame2003-dialsharexy = "enabled" mame2003-mame_current_mouse_enable = "enabled"

I didnt verify if you actually need mame2003-dialsharexy = "enabled" but Im glad it is working

B) in /opt/retropie/configs/arcade/retroarch.cfg, add:

input_player1_mouse_index = "MOUSEINDEX"

Where:

MOUSEINDEX is the index for your mouse /dev/input/mouse*. I needed to test through a couple as what I needed to enter above, wasnt the same as the device's index. Unclear how these correlate Your retroarch config (in this case arcade) may be different for your emulator. Easiest way I know to determine the config is when its running ps -aux | grep retro and look for the program and its referenced config file

@bollwerk analog sharing is how the lr-mame2003 core work works out of the box. I have a trackball working just fine in millipede and others. It shares control with spinners. The only core options I added was mame2003-dialsharexy = "enabled" which doesn’t apply to trackball games I used to use AdvMAME for analog games but now only vector and titles that don’t launch in 2003. I never had to set an option for mouse. Maybe I left it default? I certainly didn’t add an option for it.

@dunginhawk ---awesome, sorry I didn't get back to you sooner. Glad you found the dimensions!

@jonnykesh I don't think you were being rude. I appreciate your help. Don't worry, I am not that sensitive. All advise is helpful.

@rbaker
OK thank u.
PLEASE read my new post. Maybe u will be able to help?

What are the two images? I saw in your other post about this issue that you were using Motion Blue v5. Are you saying that the trackball works with the default Retropie image from this site?

Ask the author of Motion Blue for support if you can't get it to work. Only the official Retropie image is supported here.

@capeman, thanks for the encouragement. It's currently hooked up via VGA to an flat panel monitor. Given the age, I'd say maybe it has DVI, but unlikely to have HDMI. My plan was to use the existing cable with VGA to HDMI adapter.

Any thoughts regarding the remote access part?

How do I do this in advmame ? I'm confused as to where to input this text:

marble/input_map[p1_trackballx] mouse[1,x] -mouse[1,y]
marble/input_map[p1_trackbally] mouse[1,x] mouse[1,y]
marble/input_map[p2_trackballx] mouse[0,x] -mouse[0,y]
marble/input_map[p2_trackbally] mouse[0,x] mouse[0,y]

"advmame.rc" where is this file so I can locate and modify it using notepad++ and WinSCP ?!

Check to make sure none of the spare trackball button wires inside aren't touching each other.

You can add more ports with a USB hub.

@caver01
The 106 roms in question don't work in AdvMame .94 either :-(

Good idea about switching the wires on the trackball. I'll take a look and see if it's an easy fix - then it will be right for everything going forward. Thanks for the idea!

@barbudreadmon Thanks, that sounds great. I'll test it today or in the next days. My Pi is doing the update from source right now, but I don't know yet if I'll have the time to test it later today.

AFAIK there should be no need of different mouse devices for trackball/spinner/lightgun, because they all use the same /dev/input/event… devices. (Multiple mouse devices may be needed for games with multiple mouse-type devices, though.)

Trackballs and lightguns will use both axes of a mouse device, whereas spinners will use only one axis per spinner. For two spinners, that may be X and Y of a single mouse device if they are connected that way. Others, like the USB adapters that come with the SpinTrak spinners, will map them as separate mouse devices and only use their X axes.

https://retropie.org.uk/docs/Spinners,-Trackballs,-Lightguns,-and-other-Mouse-Devices/ describes the different kinds of axis mappings in great detail.