SteamBoy Turns a Full Steam Deck Into Something That Fits in Your Palm

Photo credit: PhyFawkes
PhyFawkes stared at a Steam Deck motherboard one day and wondered how small it could actually get. The answer now sits in a case that matches the original Game Boy’s footprint. Thirty-two millimeters thick. Same basic outline. Only SteamBoy holds modern PC hardware capable of running current games.

SteamBoy Demo
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The Steam Deck motherboard has been left totally intact, which means the original batteries, speakers, and every single face button are still in place. Nothing was chopped or extensively reworked, which is more than you can say about most custom conversions. The packaging and board layout have been revised, with a few longer ribbon cables and some careful positioning that allows the parts to nest together within the ultra tight body. The battery itself is extended across the gadget, jamming itself between the board and the ultimate screen, which is a bit of a miracle.

Proper cooling received the greatest care, as a 30 by 7 millimeter fan and heatsink combo purchased from AliExpress was installed on a custom 3D printed PETG mount, which bends exactly the correct amount and can withstand heat without becoming bent out of shape. After applying a 50 millivolt undervolt to both the CPU and GPU, the system was comfortably cruising in the low 70s Celsius while playing Tunic. Clair Obscur: Expedition 33 pushed it into the 80s, but it surprisingly remained playable, despite hot air escaping toward the hands and a little square above the heatsink becoming warm.

The face buttons are already functional, but the shoulder triggers and bumpers are still buried beneath the controller boards for now. However, it is entirely possible to wire them out afterward. The right trackpad can already be used as a second analog stick via Steam Input if the need arises. The video output works right now, so you can connect the build to a monitor while the internal display is unfinished.

The main display is the most significant remaining challenge, with a 1200 x 1080, 90Hz AMOLED panel intended for VR headsets currently awaiting installation. Because the pinouts do not match, connecting it necessitates a custom adapter board as well as a BIOS update similar to those used in the DeckHD and deckSight projects. Until that work is completed, the SteamBoy will only function headless or with an external display.

The case itself is a carbon copy of the original Game Boy in terms of proportions, with the exception of some added heft from current components. It appears very familiar at first glance, but closer inspection shows the Steam Deck buttons and a modern layout. The long-term strategy involves improved heat management and, maybe, replacing the case with one made of metal with a plastic outer layer for comfort. Oh, and the missing shoulder controls haven’t been forgotten.

PhyFawkes posted the project (which is still quite far along) on Reddit, along with a short demo video and deconstruction. The hardware is already performing all necessary functions. Once the screen adapter and BIOS work is completed, the final piece of the puzzle falls into place, and a full Steam Deck experience is suddenly housed in a body tiny enough to fit into a jacket pocket.