18X: 9 bit data transmit / receive

"Here is an example of sending up to 9 bits of data at one time over an audio line to a picaxe 18X chip.

In the movie, only 8 bits are used as the sound command on the picaxe can have the values 0-255.

The data is sent and received as a three oct byte, as opposed to a nine bit byte.

The grid that is shown / played in the movie has a repeating loop (time in steps) on the X-axis and various pitch values on the Y-axis. "

http://www.youtube.com/watch?v=chALSXnuJB8
0:55