Dear Sir,

Output of sound with a 8052 is treated in the book of J.L. Vern :
"Développement avec la famille 8051" Thomson Publishing editor (approximate name, I have not the book under hand). The book, in french, certainly exist in english. This is the most usuful book on 8052 I have ever found. Vern connects a R-2R resistor network on 8052's P1 port and an Op Amp, a cheap, do it yourself, DAC.
Software is simple and given on a CD-ROM with a lot of other useful files.

Best regards,

Jean MASSON