Yet another workaround:
The standard command with which pcsx is run in Retropie does not always work without errors. Replace it, using the following steps.
Edit /opt/retropie/configs/psx/emulators.cfg so that the command to launch pcsx-rearmed reads:
pcsx-rearmed = "/opt/retropie/emulators/pcsx-rearmed/pcsx -cdfile %ROM%"
A new (hidden) config dir will be created: /home/pi/.pcsx/. And a dir where you must place the the PSX BIOS (i.e. the file SCPH1001.BIN): /home/pi/bios/.
Redo the settings for pcsx. They will be saved in /home/pi/.pcsx/pcsx.cfg. Do NOT copy the file 'pcsx.cfg' from /opt/retropie/configs/psx/pcsx/! You can, however, copy other settings like save files from there.
When certain emulators crash then the command line on my Pi (running Raspbian 9 Stretch) is unresponsive. The Pi does, however, respond via ssh. But no matter what process I kill, the console on my television stays non-responsive. Anybody got some tips & hints?