Here is a photo of my first project case for retropie. Although a tight fit, all components except a hard drive will fit. This one features working PSX ports and 4 additional USB ports at the front using a USB hub. My final version ended up with the yellow inserts being recut out of the same colour plastic as the console to match.
I’ll dig out some more photos as I am back tinkering with this one as the Neo Geo X one is done.
I used a PSX to usb dual converter, removed the original ports off the psone board and soldered the pins, replacing the converter ports. Ebay sell them for a few pounds. I think you can use the GPIO ports but that seemed too much hassle. RetroPie reads the usb as a twin joystick, works out the box.
The biggest pain in the arse is wiring in the 4 usb hub above it where the memory card used to sit, not much room there.
I Have another PSone unit that I will perform the same on, I’ll take photos of that process as I know how to make it smarter looking.
it’s a standard 4 hub usb off ebay again, about £3, just strip back the plastic on them to make them more flexible. the faceplate I made on a laser cutter using plastic from another project which happened to match, the memory card doors are too thin and small to adapt.
It’s not pretty inside with all the glue used to hold them but once put together you don’t see anything of this.
Removed the original power connector as that was on the original motherboard, used a larger power pin jack and wired that to the pi via the mini usb. Before the wires reached the mini usb of the pi I added the original switch connecting the live so you could switch the unit on and off. I never used the original playstation power block, you could but you would need to lower the voltage, instead it plugs in as standard but uses a 5v power block instead.
It should be the top row nearest the edge of the board, I took these two ports off the board it’s far easier, if you leave the board in you will have little to no height for the pi b+ to go in, if you look at the photo of mine open you will see the tops of the USB ports hang out into the CD area. The ports glue back in the same place and are held in with screws.
apart from a cover for the HDMI port and a new power port mine is done, downside is I can’t fit a hard drive in so a large SD card is the only way.