> From: "Vlasov Serge V." <sv@IAE.NSK.SU>
>
> Hello ladies & gentlemen.
>
> I need a single-chip inexpensive sound synthesizer.
> I realize that PIC (say, 16C84) + external DAC would do all,
>      but they are TWO.
>
> There are many devices with on-chip ADC, but I failed to find one with
>      on-chip DAC, inexpensive and with small pin count (like PICs are).
>
> Could somebody suggest me anything, please?
> Help me to guess WHY don't they (manufacturers) integrate DAC into
>      controller chips?

Well, they do.  The PIC16C73/74 has an on-board PWM which is a form of
DAC.  The PIC PWM has a resolution of up to 10 bits, depending on the
highest desired carrier frequency.

Getting a DAC function is the easy bit.  The hard bit is generating
a useful waveform to send to it.  Square, triangle, saw-tooth and sine
waves are easy enough.  For a synthesiser you will need attack/decay/
sustain/release control.  This implies a multiplication operation in the
digital domain: not all that easy using a PIC without hardware multiply.
It can be done, but your output frequency may be limited to a few hundred
Hertz.

Regards,
SJH
Canberra, Australia