You press Home/the PS button and you can select from several video settings amongst the options. You can go for 1:1 pixel (where applicable), stretch it to fit from top to bottom while retaining aspect ratio, stretch to fill the screen fully, or (I believe) even zoom in.
Thanks. I know it was probably a real basic question but as strange as it seems I'm still on the fence with which PS1 classic title to purchase. Just want to try and ask the questions that I'm sure I'll have once I do actually buy my first game. Thanks again.
I'm playing FF7 on psp now, and just like SOTN, it tends to have some unused black space on the top and bottom of the typical 4:3 screen, allowing you to use the manual zoom function to zoom in more than you'd expect to fit the psp wide screen aspect ratio. You'll have a little unused space on the side, but less than if you were actually blowing up a 4:3 image.
The only time I ever even notice it is when a dialog text box happens to have an edge outside that area, although I haven't seen any actual text obscured and I haven't noticed any cutoff in the maps, characters or menus.
I'd guess you can probably do something similar on many ps1 games.