PSIO Switchboard Installation (PS1)

the psio is a device that plugs into the back of the ps1 and allows you to load games from sd card instead of the disc drive, while retaining the disc drive this only works on full size ps1s not the psone smaller variant as it does not have the expansion port if you are not interested in keeping the disc drive i recommend an xstation instead which directly replaces the disc drive overview in order for the psio to work you must install a small mod that is just an analog switch toggling a few data lanes, which switches the data path between the disc drive or psio unit at the back of the console this mod is called the switchboard there are various installation guides online, for example here , however there are some errors in the install guides and the mod board itself which i will highlight here first make sure the console is fully working before starting, and your disc drive can load games, and the console if no disc is inserted goes to the memory card screen correctly, every time you boot it up common install steps all versions of ps1 can have all of these points soldered in the same place on the extension port pins solder the following points and make the single trace cut ground 3 5v (goes to diode pad not the vcc pad on the mod chip) en pad (also cut the trace below en) pi pad pe pad the remaining points (xe, xi, ce, ci) and trace cuts are specific locations on each revision of board until i work through installing them on each specific revision, follow the guide here for the remaining points and any trace cuts it advises to make do not follow the steps for the points we have already soldered, make sure they match our pads above also do not follow the pu 18 guide, it is wrong use our guide below identify which version you have which will dictate where you solder specific wires too most of them are common but there are 4 wires and several trace cuts that are specific to each version remove the motherboard and inspect the rear, where the version number is written pu 18 install for pu 18, we need to make 2 cuts here on the ci/ce traces near the bottom center of the pcb to the left of the large gold letter b then pre tin the vias to the right and solder them to the ci/ce pads of the chip finally we need to solder the two wires for xe and xi they are located about mid way on the left side of the pcb finally the finished mod should look like this notice i have used some clear uv solder resist to tack the wires in place and stop them moving boot up if all has gone well, the console should boot up as normal without the psio installed and simply load from disc as it did before with the psio inserted you should be presented with the psio logo for a few seconds followed by the loading screen and then games list (presuming you have the sd card formatted as fat32 or exfat and have the menu sys file in the root todo menu photo if you have issues check if without the psio your games still load and/or you get to the memory card menu if you do not, then the issue is with the install of the switchboard (make sure for example vdd is soldered to the diode output not the vcc input) if you still have working discs but the psio hangs at the psio logo without any progress bar, check your sd card (perhaps purchase a better brand) and format it corrrectly, including the menu sys file on the root ensure the ext port is cleaned with ipa also