@bizt go into the retroarch settings from the emulator. Back out until you see settings and select that. Then go to video, and then change the aspect ratio to either 4:3 or default. Then go back a couple menus and go to to
Configuration, then save core overrides.
Another option if you wanted to keep the stretched out 16:9 image, it turning on Bilinear filtering in the same video menu, and then save the core overrides for that. The filter helps smooth out the chunkyness of ps1 games. Or do a combination of both
Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first