I’ve written a tutorial how to configure a game controller in jzintv in the post below.
The links seem to be down in that post so I have included the required files in the attached zip.
The method makes use of shell scripts to launch games so before you start, you need to edit es_systems.cfg. The best way to do this is to copy the file from /etc/emulationstation to /home/pi/.emulationstation. Now edit the permitted extensions to only include shell scripts, .sh, so that the Intellivision entry reads as below:
<system> <name>intellivision</name> <fullname>Intellivision</fullname> <path>~/RetroPie/roms/intellivision</path> <extension>.sh .SH</extension> <command>/opt/retropie/supplementary/runcommand/runcommand.sh 0 _SYS_ intellivision %ROM%</command> <platform>intellivision</platform> <theme>intellivision</theme> </system>
To make sure that the shell scripts launch, you will need to edit /opt/retropie/configs/intellivision/emulators.cfg to the following:
Now add event_diag.rom and Event Diag.sh to the Intellivions roms folder, restart ES with F4 and you are now ready to begin the tutorial.
Let me know if you need further guidance.