When PD starts, audio is off, and you have to click the “compute audio” tick box. But what do you do when you want to start it automatically, like from a batch file?

The answer is, cryptically enough, “; pd dsp 1″. Below is a screenshot. Make sure that this goes in a message box.

Note that you can start a pd patch just with a “pd patch.pd” command from a command prompt or batch file. This patch does nothing interesting (it just plays an annoying sine tone) but it does it automatically.