I wasn't documenting changes I made to the retropie project. As is so often the case, I suppose, each one seemed relatively straightforward and memorable when I figured it out or googled it right. Now, though, I'm looking at starting from scratch with a pi 3 and may have to replicate various bits of config. So here's what I remember. Imaging the SD card and whatnot is as you'd expect. SSH in as user pi and password raspberry. ROMs go in the folders for the appropriate emulator. get rid of screen borders by editing /boot/config.txt and uncommenting #disable_overscan=1 I resized the SNES screen just with screen ratios in the retroarch menus gba only works when you put gba_bios.bin in the same folder as /opt/retropie/emulators/gpsp, and I altered the config at ROM startup to use gpsp as the default emulator. Controls aren't sorted yet. Will add more as I remember.