Sounds like you guys started talking about what you are doing on your own projects rather than what might be best for Rok. I take it from Rok's comments that he wants something less complicated.
if you start Mame with a CP that has 2 players and a couple of guest show up. You can not just plug in a extra CP and expect it to work.
you must restart Mame for it to see the extra CP.
I would assume this is because they are gamepad encoders you are using. I think 2 keyboard encoders would not have this issue if you plugged the second encoder in when MAME is already running because there is no such thing as multiple keyboards. I have not tried this, so correct me if I am wrong.
The solutions i can think of would be:
1. Keyboard encoder for each CP with the secondary encoder set as standard player 3/4 keys(assuming your encoder can save settings). The secondary encoder could just plug in via USB port on the main CP. More encoder cost but less work. Same can be done with an extra trackball CP.
2. One keyboard encoder in main CP and use D-sub or similar to interface the second panel.
3. All gamepad encoders/hacks in main CP always plugged into computer then use D-sub or similar to interface the second panel.
Would it be possible to make a standard 2 player fighter set up CP, but also have additional mini CPs like, to add a 3/4 player or a trackball or something that can plug into the main CP?
I dont have room for a full arcade at the moment and was wondering if something like this was possible.
(I am talking about one that would plug into a TV screen that is only a CP)
Rok, I assume if you want to plug the CP into the TV then you are going to have your computer in your main CP. Have you decided on the product you want to use for your encoders?
If you don't mind spending more in order to make the wiring easier you could do solution 1 that I mentioned above. You will just need to mount a USB port on the outside of your main CP (can use a USB extension cord). This will save you dealing with D-sub connectors (or whatever type of connector you would have chosen). It will also take a little less wiring. In the end you will still have to do wiring and you may end up thinking doing the D-Sub is not so bad.
I can understand wanting to take the easier route if you are new to wiring stuff and not very worried about added costs of additional encoders. You will probably get it done faster also.
I dont even know what a d sub is...
Looks like I'll just go with a franken panel
A lot of people have done 4 player CPs with a trackball, that look very nice. They are not usually what I would consider a franken panel. Were you planing more add on panels then just player 3/4 and the trackball?