Hi there!
Sorry for the ones who have seem ths before - I am new to this site and I only just discovered this Tacho forum!

I have just written piece of software that can measure the revolutions of an engine simply by 'listening' to it through a microphone and analysing the sound. A first beta version is on my website at [link=http://www.esser.u-net.com/rpm.htm]http://www.esser.u-net.com/rpm.htm[/link]
Feel free to download this program, I would appreciate any feedback, my email address is on the site.