🚀 go-pugleaf

I've been thinking about building a little device
to record and play back digitized sound.  the idea
would be to have d-a and a-d converters hooked up to
a single-chip micro with, say, a megabyte of low-power
static ram.  even something as wimpy as a 68HC11
could do linear predictive coding, compression or even
(non-realtime) speech analysis.  the device could
also be a dictating machine, appointment book, etc.

know of any microcontrollers with converters on-chip?
recommendations on d-a and a-d converters?
how does speech sound using a zero-crossing detector?

thanks,
mark