They used the webaudio API to send serial data to a remote Arduino. The hack uses a FET, a capacitor, and a few resistors. They didn’t quite build a real modem with the audio.

[HC] took a gander around the Googles and saw a number of people trying to read NAND flash chips with an Arduino. It’s an interesting problem; at 16 Megahertz, [HC] is looking at about 60 nan… ...

As explained by Arduino to Go, each color band on the resistor corresponds to a number but this can differ depending on the band's placement.It's not complicated, but the sheer number of colors ...