When Sony designed the original PlayStation back in the ‘90s, they didn’t have any reason to make it any smaller than it was. As such, its motherboard was larger than it absolutely had to be. On top of that, technology has progressed a lot over the past three decades, which let Thedrew create what is likely the world’s smallest PlayStation motherboard.
This kind of thing would be fairly trivial to achieve with a modern SoC (system-on-chip) and emulation. It could also be done with an FPGA (field-programmable gate array) by someone with the relevant expertise. But Thedrew wanted to use real PlayStation chips, which is why this project is so interesting.
Thedrew salvaged the important chips from a PSONE with the PM-41 motherboard version, which had the smallest chip packages of the PlayStation varieties. Those chips include the CPU, GPU, SPU, RAM, and BIOS. He then designed a new, compact motherboard to host those chips, replacing all of the auxiliary circuitry and components, such as for supplying power, with modern alternatives that take up less space. Timing isn’t critical with the PlayStation hardware, so he didn’t need to worry about tuning trace length or anything like that.
The result is a motherboard less than a quarter of the size of the original. Additional boards provide power, controller connections, video output, and replace the disc drive.
Why would Thedrew do all of this? Mostly for fun. But it also opens up the potential for other projects, such as a handheld PlayStation.