Peter, I used the Maxim MAX525 12-bit quad serial DAC. Easy to use (CLK, DATA and CS), and also free samples direct from Maxim. Cheers, Neil -- Neil Johnson :: Computer Laboratory :: University of Cambridge :: http://www.njohnson.co.uk http://www.cl.cam.ac.uk/~nej22 ---- IEE Cambridge Branch: http://www.iee-cambridge.org.uk ----