Vsync

How does VSYNC work in SDL? Can I have it where I explicitly wait on it or
does SDL always wait on it (or maybe never wait on it?).

I’m migrating from a DirectX based framework and DX has a call:

m_lpDD->WaitForVerticalBlank(  DDWAITVB_BLOCKBEGIN , 0 );

and I was wondering if this is even relavent in SDL any longer. I’d like to
keep the option to enable/disable vsync, but its not completely necessary if
its not available.

thanks,

Michael Rich
http://www.AlphaX86.com