Configuring Osmose Controls: How To Instructions

[Used2BeRX]

This is a Game Gear and Master System emulator that is not under the libretro/retroarch umbrella. Most people wouldn't need it, but I feel that when using a Pi Zero it's better to keep all of your options open just in case.

This one is definitely the strangest configuration I've seen so far. It took me quite a while to find the location of "Osmose.ini" since a lot of the information online for it is old and pointed you in the wrong direction. Only after you've used the emulator for the first time will you find it in a new directory called /home/pi/osmose_files/

But after you've found it, you realize that you can only re-map keyboard keys to this file.

To be able to map controller inputs to the Osmose emulator, you need to add commands to the command line launch of the emulator. Currently, that exists in your emulators.cfg. In this example, we'll use the Master System version.

1. Go to the directory /opt/retropie/configs/mastersystem/ and open emulators.cfg.

2. The Osmose launch line should look like this:
   osmose = "/opt/retropie/emulators/osmose/osmose %ROM% -tv -fs"

3. You need to change it to look like this:
   osmose = "/opt/retropie/emulators/osmose/osmose -joy 1 -joy1 0 -joy2 1 -joystart 9 -joyquit 8 %ROM% -tv -fs"

-joy1 0 = CROSS on the PS3/4 USB controller
-joy2 1 = SQUARE on the PS3/4 USB controller
-joystart 9 = Start Button on PS3/4 USB controller (I hear this is only used in Game Gear)
-joyquit 8 = Select Button on PS3/4 USB controller

Unfortunately, I could not find any information online anywhere about binding both the Start+Select button to exit the emulator, so keep that in mind that pressing only the select button will exit the emulator.

Also, the emulator displays slightly less than full screen and I could not find any information about how to correct that. And lastly I do not know if there is a way to map the directions to the DPad, so you are stuck with the Left Analog stick. This is the only alternative to Pico for the Game Gear though, so chances are it will probably be useful for a game or two at least with a Pi Zero.

For Game Gear, follow the exact same instructions, but the emulators.cfg you need to edit will be located in the following directory: /opt/retropie/configs/gamegear/

If anybody has any suggestions for how to bind both Start+Select or to make the emulator display at full screen let me know and I will edit these instructions.

OTHER NON-LIBRETRO CORE CONFIGURATION INSTRUCTIONS:
DGen for Sega Genesis/Megadrive: https://retropie.org.uk/forum/topic/10732/configuring-dgen-controls-how-to-instructions

mame4all for Arcades: https://retropie.org.uk/forum/forum/topic/10771/configuring-mame4all-controls-how-to-instructions

OTHER GUIDES:
Making Headers on Atari 5200 Roms to Autorun in Retropie: https://retropie.org.uk/forum/topic/10337/making-headers-on-your-atari-5200-game-images-to-auto-run-in-retropie

PROJECTS:
Making Pre-Made gamelist.xml With Xtras Media Collection: https://retropie.org.uk/forum/topic/10406/making-premade-gamelist-xml-with-xtra-media-collections/26

Upgrading the Atari 800/5200 Emulator (thanks to future.child and jfroco): https://retropie.org.uk/forum/topic/847/atari-5200-new-version-of-atari800-beta-two-triggers-moon-patrol-hat-start-and-exit-buttons/126

Atari 5200 Controller Configuration Project: https://retropie.org.uk/forum/topic/10764/atari-5200-controller-configuration-project

[POPEYE]

@Used2BeRX
Is it possible to configure gamepad for second player?
By the way, -joystart seems not working for Master System (it is only for Game Gear).