Sony’s original Playstation wasn’t huge, and they did shrink it for re-release later as the PSOne, but even that wasn’t small enough for [Secret Hobbyist]. You may have seen the teaser video a while back where his palm-size Playstation went viral, but now he’s begun a series of videos on how he redesigned the vintage console.Luckily for [Secret Hobbyist], the late-revision PSOne he started with is only a two-layer PCB, which made reverse engineering the traces a lot easier. Between probing everything under the microscope and cleaning the board off to follow all the traces in copper, [Hobbyist] was able to reproduce the circuit in KiCAD. (Reverse engineering starts at about 1:18 in the vid.)With a schematic in hand, drafting a smaller PCB than Sony built is made easier by the availability of multi-layer PCBs. In this case [Hobbyist] was able to get away with a four-layer board. He was also able to ditch one of the ICs from the donor mainboard, which he called a “sub-CPU” as its functionality was recreated on the “PSIO” board that’s replacing the original optical drive. The PSIO is a commercial product that has been around for years now, allowing Playstations to run from SD cards– but it’s not meant for the PSOne so just getting it working here is something of a hack. He’s also added on a new DAC for VGA output, but otherwise the silicon is all original SONY.This is the first of a series about this build, so if you’re into retro consoles you might want to keep an eye on [Secret Hobbyist] on YouTube to learn all the details as they are released.