He dismantled an old USB memory stick, fitting it with an ATtiny85 with its required components on a small piece of perfboard. Using the knowledge he gleaned from his previous USB HID tinkering ...

flash memory storage, RAM, Bluetooth, Wi-Fi, operating systems, and an HDMI connector. Some computer sticks also offer microSD card slots, micro USB, and/or USB 2.0/3.0 ports for storage expansion.