So I logged on to my router and easily enough found the IP address of the Pi. Now for another download, this time FileZilla. Load it up, enter the address and the username/password and it shows a file directory I can recognise! All good steps, so I deleted all the stuff under the mame roms directory and copied over the invaders zip file again. Start up, and same issue. Somebody suggested on a forum that the mame.cfg and es_system.cfg need to have the right roms directory in them. Found the mame.cfg OK and checked it – all good. Can’t seem to find the es_system.cfg and the guy in the forum said it’s located /etc/emulationstation. In my ignorance I assume /etc/ means etcetera and I’m supposed to substitute /home in it’s place, so a few days of confusion.
Raspberry Pi with a box and Logitec F310 controller, and Retropie