In my previous post, the path to the minimal.cpp file is incorrect so that may explain why you couldn’t see any code when using ssh.

As file names and directories are case sensitive in Linux, the command should be

sudo nano /opt/retropie/emulators/mame4all-pi/src/rpi/minimal.cpp

What I did was write the Retropie 2.2 image to SD card, comment out the lines in the minimal.cpp file and then recompile using the following commands.

cd /opt/retropie/emulators/mame4all-pi/
make