

Open the RPCS3 app again and then select File->Install Firmware, this will open up a window from where you will have to locate the previously downloaded firmware file i.e.The downloaded file will be named PS3UPDAT.PUP. Download it with the browser on the Steam Deck. Visit the official PlayStation site to download the latest PS3 system software.This app will show an error of missing firmware.


Simply put, to emulate PS3 on the Steam Deck you need to download and install the RPCS3 app and have a PS3 game in your storage to make it work.
