How to flush the cache of a whole drive

[Stefan Kittel]

Hi...

I'm doing an backup to an external drive (via firewire). after copying many files I want to flush the cache from the whole drive to remove it.

I found sync.exe at sysinternals.com but without sourcecode.

It should function under all windowses (95,98,me,wk,nt4,...).
I somebody knows a way for one I would be greatfull too.

thanks in advance

Stefan Kittel