.iso is not a good format for Playstation games, Handys - if the CD is a multi-track CD, the .iso format does not include the information to play the extra tracks, which may include music, sounds, FMVs etc.
.bin/.cue is better, and the best formats are .ccd/.img/.sub and .mdf/.mds. You should re-rip your game to one of these formats. It's no use converting your .iso to another format, you need to re-rip from your original CD.
The -r switch is a command line switch. There are various ways you can use it; if you start pSX from the command line, add a space after the executive name, then add -r. Or, create a new shortcut or launcher to start pSX, right click it and select Properties. In Windows, in the panel labelled Target, move your cursor to the end on the line and, again, type a space and then -r. Click OK. In Linux, do the same in the Command panel and click Close. Now your new launcher or shortcut will start pSX with event rescheduling enabled and your game should play Ok.
Or the easy way is to download and install
Ultima's pSX Frontend and, when you create a profile for your game, go o the Switches tab and tick the box against -r Enable Event Rescheduling before you save it. When you start the game from this profile, event rescheduling will be enabled.
