A common issue with the PSX is that, like all CDs, all our games get scratched, and the lasers get worn down, leaving you with skipping or unplayable games :(
Around 2013 or so, I came across a project in development called PSIO. It's goal was to create a device that would run PSX games off of an SD card. No more burnt out lasers or scratched discs! After two years of patiently waiting, PSIO was released to the public; so of course I ordered mine as soon as I could.
The device plugs into the serial port of your fat PSX (unfortunately you can't use it with the newer, smaller playstations) and you plug your SD card with games on it into that. You also have to solder a tiny chip onto your playstation's motherboard - What this does is redirect the motherboard to read from the PSIO instead of the cd laser.
What's that you say? You want one of these spectacular devices as well!? As of February, 2017, I believe the PSIO guys are selling them as they are available; And you can sign up to be notified when they are. The only catch is that they cost $150 US and you are required to do some soldering (I believe you can ship them your playstation and they'll install it for you, though). Check out their website here:
Some pics of the PSIO:
The cartridge that plugs into the PSX. You can see the SD card sticking out of the top
PSIO comes with a dandy sticker to show off how cool your playstation is now
The PSX motherboard with the switchboard installed. Besides adding the wires, you also have to cut 3 traces on the motherboard, so an exacto knife or something is required as well
My playstation with the PSIO plugged in. You can see my Raspberry PI there too
When the PSX Bios boot up you can notice that the SONY label or whatever is replaced with the PSIO label
You run games through PSIO's menu system, which additionally lets you run games from disc too if you want, which is pretty cool