Board version and mission planner

How can I determine what the version of my board is? Arducopter S500 (2015). I can’t get the mission planner to upload anything. I keep getting a message to upgrade the boot loader and disconnect the mavlink. That takes me to the install board that wants me to make the mavlink connection again. I’m confused.

What do you about the board in general? Was Ardupilot ever installed on it? From 2015 it may be an old APM Flight Controller which is no longer supported and most likely can’t be updated beyond what’s on it if that’s true. Time to replace it.

Thanks for the reply. I’m a newbie to drones and RC itself so please bear with me. It was new in the box.
How can I find out what version software is installed? Right now It refuses to connect to MavLink.
Here it is. APM 2.8 with GPS. It only shows 906.00 memory. Hopefully, that’s 906k.


The last supported version of that Flight controller was 3.2.1 which is very old. Version beyond that do not support that Flight Controller. However it should connect to Mission Planner via USB.