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TypeBoy & TypePak

The TypeBoy, designed by FlatFootFox, is a unique low-pro split keyboard requiring a Game Boy cartridge to function.
Published August 30, 2023
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Stu (FlatFoofFox/TheStuChef/ImStuBTW) released the design files of his TypeBoy keyboard with the unique TypePak system – a microcontroller stack fit in the shell of a Game Boy cartridge.

I managed to fit a XIAO BLE, Sharp Memory Display, shift register, and LiPo battery inside of a Game Boy Advance cartridge. The "TypePak" is mostly just for aesthetics, but it will make swapping microcontrollers more straightforward if I use it on future builds – Stu.

So the TypePak is a custom keyboard daughterboard with a XIAO nRF52840 Bluetooth microcontroller (aka XIAO BLE) for ZMK support, a SN74HC595DT shift register, a low-power LS011B7DH03 Sharp Memory Display, and a 401020 LiPo battery designed to be housed inside of a standard aftermarket Game Boy Advance cartridge.


Seeing Stu's project I immediately recalled an image engraved into my retina: a post by mujimanic, owner of Sneakbox, about the Giga40 "clackertainment system". Looking it up, that project (probably a render) was posted almost 3 years ago, with an update of a working prototype last year. According to a reference in Stu's post, the TypeBoy design was in part inspired by Muji's original idea, and it's now out there with all the design files shared – for the more DIY savvy folks.

If you like the TypeBoy and are ready to get your hands dirty, every pin is broken out in case you find some novel use for SPI, or chose not to use the screen. The battery trace and reset pins are also broken out so that you can put a power and reset switch on the main keyboard. Going more off-script may require some destruction though: e.g. you'll need a Dremel or similar tool in order to cut a USB-C port in the side of the cartridge shell.


All this is covered in detail in a nice blog entry by FlatFootFox, along with specs, insight into design decisions, as well as tons of useful tips. Check it out!

Other than its GBA-compatible cartridge slot, the keyboard itself is a pretty standard 58-key split ergo. The author did some experimenting swapping out volume rotary encoders for thumb switches "to try and keep the Game Boy vibes going". Everything's topped off with FK Custom keycaps.


  • 58 low-pro keys
  • reversible PCB
  • hotswap
  • XIAO BLE via cartridge system


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Published on Wed 30th Aug 2023. Featured in KBD #133.


GIGA40: with cartridge system

The GIGA40 is a strange concept of mujimanic with features like replaceable cartridge and serial connector (more pics).

Giga40 with cartridge

Giga40 progress. Cartridge implemented by mujimanic.