The world's first hardware-accelerated DK Bongos - PS/2 Keyboard adapter
The DK Bongos only have six inputs. Each bongo is split into two halves, a front button and a back button. The remaining two controller inputs are the "Start / Pause" button on the side of the center block and a microphone situated on the top of the center block.
On September 27th, 2004, Nintendo released the rhythm game Donkey Konga for the GameCube. When fans purchased the game, they also received the DK Bongos, a GameCube controller disguised as a pair of bongo drums, albeit with only a limited number of inputs. Nintendo would go on to continue the series, releasing Donkey Kong Jungle Beat and Donkey Konga 2 worldwide in the spring of 2005. Japan also saw an exclusive third release, Donkey Konga 3, which was never released outside of Japan. These new releases received increasingly negative reviews, and development on the series was canceled. While the hope for new Donkey Konga titles may have died off, the DK Bongos have lived on.
The DK Bongos have been a passion of mine for - well, too long. It all started with a question and a joke between my housemates over dinner: what makes a programmer a real programmer? We may have not been the first people to ask that question, but the truth is still astounding: a software program is just a very specific ordering of ones and zeros. Leaning back in my chair at the dinner table, I remembered the VR videogame Job Simulator. There's a keyboard in this game with only a "1" key and a "0" key. That's when it hit me. A real programmer truly only needs two things to write software: a one and a zero. And so was born the binary keyboard, made possible by Nintendo's obscure controller.
This hobby project has been a surprisingly good learning opportunity for many things: memorizing binary and hexadecimal; learning the Instruction Set Architecture (ISA) underneath ARMv7; becoming familiar with ELF binaries. Now, the DK Bongos lead me deeper once more: the world of digital design and ASICs.
The DK Bongos utilize the Joybus Protocol, sometimes referred to as the GameCube Controller Protocol, to interface with the GameCube console. To interface the DK Bongos with something other than the GameCube, fellow bongo enthusiasts - such as streamers who love to play videogames with obscure controllers - must purchase an adapter which converts the GameCube Controller Protocol to USB. While there is software to read the USB input and bind it to certain actions or keys, it is often clunky and not compatible with all operating systems.
My first pass at turning the DK Bongos into a binary keyboard was to buy one of these GameCube-to-USB adapters and to use a custom Python program running on a Raspberry Pi to map button presses with keybindings. But the setup was clunky, with a Raspberry Pi running the program to translate the USB output from the adapter; I could not use the DK Bongos in any other program, e.g. hexedit. That is why, in the spirit of being real programmers, we now joyfully turn to replacing the adapter and the Raspberry Pi with our custom hardware.
This ASIC converts the serial output of the DK Bongos, which is encoded using the GameCube Controller Protocol, to a serial output which is PS/2 encoded. With a hardware adapter, the DK Bongos have the potential to become like any PS/2 keyboard, agnostic to both application software and operating system. A hardware adapter frees the hobbyist to use the bongos in ways and applications which were not possible before, and certainly never intended by Nintendo.
If we can successfully design an ASIC to convert the Joybus Protocol output from the DK Bongos to valid PS/2, then the hope is to fabricate these ASICs courtesy of the Google / Skywater / Efabless Multi-Project Wafer (MPW) program. If our project is selected for tapeout, we plan to continue hardware development with the design of a PCB and casing to produce a fully-functional prototype.
- http://www.int03.co.uk/crema/hardware/gamecube/gc-control.html
- https://n64brew.dev/wiki/Joybus_Protocol
- Benjamin H. Powers, for believing in the dream / meme of binary keyboards and for hearing my new ideas with the same enthusiasm I had, no matter how crazy they must have seemed
- Benjamin P. Reilly, for being my closest friend, a role model of courage, and for inspiring me to be the best engineer I can be
- Scott A. Tornquist, for encouraging me to see the best in myself and for never giving up on me, even when I wanted to give up on myself