[lug] Ethernet sound card

[Peter Hutnick]

I seem to have utterly failed to communicate.

A picture is worth a thousand words they say.  See
http://hutnick.com/network_sound_card.jpg

Note that there is no processor.  Note that there is a DAC (and NOT a
DSP).  Note that some magic happens on the non-straight line between
Ethernet Controller and Buffer and some more (lesser) magic happens
between Buffer and DAC.

The first magical thing is that (raw) Ethernet frames with the device's
MAC are picked up (or, I think more properly, aren't dropped) and are put
in the (FIFO) buffer.

The second magical thing is that the buffer is "read" out to the DAC at
the right rate (150kb/s?  1x CD speed, anyway).  The DAC doesn't know that
this isn't output from a CD's laser.

I don't think that either of these things are insurmountable (to, say, a
third year EE student) or requires a microprocessor.

-Peter