Game Boy Labs

Lab notebook · opened 10 October 2026

A small lab for the original Game Boy.

We design cartridges, cables and ROMs for a handheld from 1989, and we only call something done when it works on the real console. Every decision and measurement goes into a dated logbook.

Projects
7
Boards
3
ROMs
4
Emulator stand-ins
0
Technical drawing: an exploded handheld console with its screen, mainboard and shell, a cartridge sliding out (5) and a link cable (6) leading to a small circuit board
Fig. 1
  1. 1–4 The console: an original DMG, our only target
  2. 5 The cartridge port: kagiboy, WiFi cartridge
  3. 6 The link port: gb-link-usb, and every ROM that talks to a computer

Register

  1. 01Slow HorizonsLandscapes drawn live by a Game BoyOpening soon
  2. 02kagiboyA hardware wallet in a cartridgeOn hardware
  3. 03gb-link-usbThe link port to USB-COn hardware
  4. 04WiFi cartridgeWiFi that can't brown out the consoleBench tests
  5. 05ClaudeBoyChat with Claude on a Game BoyDemo ROM
  6. 06SODAX on Game BoyLive prices and swap quotesOn hardware
  7. 07GB GalleryBrowse and print your picturesPrinted

Experiment 01

Slow Horizons

A Slow Horizons landscape: peaks under a haloed sun with a pine forest, in four shades of green
Plate Test piece No. 2, seed 9937f0bd, drawn by the console in 1 min 15 s

A Game Boy draws one landscape for each collector, live, while they watch.

The payment becomes a seed. The console computes the picture on its 4 MHz CPU, and every finished row crosses the link cable to the page. When it is done, the result is checked pixel by pixel against a reference build of the same code and sent to the collector's wallet.

Slow Horizons in numbers
Artistan original DMG running our ROM from a flash cart
Draw timeabout 60 s per piece
Check300 of 300 test pieces identical to the reference
Proofthe console's clock drift, measured during every drawing
Editionup to 2000, on Solana, files on Arweave
Enter the studio

Measured

Hardware

Boards for both ports

Designed in KiCad, checked against datasheets and an independent review, assembled by JLCPCB. Nothing to hand-solder.

Technical drawing: an exploded cartridge with shell halves, circuit board, microcontroller, radio module, microSD slot and USB-C port
Fig. 2 The cartridge, exploded
The kagiboy signing screen: approve sending 0.05 SOL, with the fee and the full address

02

kagiboy

A hardware wallet that lives in a cartridge. Keys stay in a secure element, and nothing is signed until you hold A on the Game Boy, with the amount and the full address on its own screen.

ChainsSolana, EVM
InsideRP2350, NXP SE050 secure element, Bluetooth LE to the phone
StatusOn a real Game Boy

kagiboy.xyzLive demoSource

3D render of the WiFi cartridge rev B: RP2350B, ESP32-C3 module, microSD and USB-C

04

WiFi cartridge

WiFi for the Game Boy and Game Boy Color with a power stage that can't brown out the console. An RP2350 serves the whole cartridge bus; an ESP32-C3 behind a current limit does the radio.

InsideRP2350B, 8 MB HyperRAM, microSD, ESP32-C3, 6 layers
Power150 mA limit, console rail held above 4.588 V
StatusDesign finished Bench tests

HardwareFirmware

Software

ROMs

Written in C with GBDK, with SM83 assembly where speed matters. The screens below are the ROMs' own output.

Technical drawing: a small USB-C adapter board with a cut link cable fanning out to five pads, a microcontroller, a crystal and two buttons
Fig. 3 The link, from cable to USB
ClaudeBoy: a joke about unresolved links, in a chat on the Game Boy screen

05

ClaudeBoy

Chat with Claude on a Game Boy: on-screen keyboard, streaming replies, printouts of the conversation.

DownloadSource

SODAX on the Game Boy: a BTC/USD chart with price and a live solver quote

06

SODAX on Game Boy

Live prices and real swap quotes from SODAX on an original Game Boy, through the link cable bridge.

How it works

Logbook

Recent entries

From the projects' own logbooks, where every check is dated and every guess is marked as one.

  1. Slow HorizonsPieces drawn on the console match the reference build pixel for pixel; first purchase minted on devnet.
  2. gb-link-usbHeartbeat: the bridge times the console's clock in PIO. Calibrated against its own 8192 Hz: 0.00 ppm.
  3. gb-link-usbPCB rev A routed, independently reviewed, 0 DRC errors. Two boards to be ordered.
  4. SODAXLive SODAX prices and solver quotes on a real Game Boy through the bridge.
  5. WiFi cartridgeFirst bench run of the radio: calibration about 30 ms at about 60 mA, the radio app on real WiFi.
  6. gb-link-usbFirst print: a Game Boy prints to our firmware and the computer saves a PNG.
  7. gb-link-usbFirst light: 1000 bytes each way between a Mac and a DMG, no errors.
  8. LabThe lab opens with ClaudeBoy and GB Gallery.

Method

How the lab works

  1. I

    Real hardware or it didn't happen

    An emulator helps while building. A result counts when it ran on an original console.

  2. II

    Write everything down

    Each project keeps a dated logbook of decisions, checks and corrections. Mistakes are logged as corrections, not erased.

  3. III

    Sources, not vibes

    Claims cite a datasheet, Pan Docs or a measurement. Anything not yet checked is marked "verify".

  4. IV

    Buildable by anyone

    Boards come with fab files for an assembly house, and the code is published. No hand-soldering, no secret steps.