Designed the IO Hat to work with the BMC64 v3.5 Raspberry Pi Bare Metal Emulator (https://accentual.com/bmc64) which when coupled with a Raspberry Pi 3A+ gives a fully functional Commodore 64, 128, Plus4, Vic20 & PET computer in a small portable box with HDMI out.

Two joystick ports allow for the full retro experience and if just playing games the keyboard is replaced with a virtual on screen version which is great for all but text adventures! Worst case you can also plug in a USB keyboard.

The 8 buttons are connected to the GPIO header as per the BMC v3.5 set-up:

GPIO16 | Menu Toggle

GPIO4 | Menu Back

GPIO25 | Up

GPIO19 | Down

GPIO20 | Left

GPIO21 | Right

GPIO24 | Enter

GPIO23 | Virtual Keyboard

Case for the IO Hat coupled with a Raspberry Pi 3A+ can be download from Thingiverse (https://www.thingiverse.com/thing:4208984) and one for a Raspberry Pi 2/3B+ (https://www.thingiverse.com/thing:4223868)