oldest audacity and source code

Where can I find the source code for the oldest version of Audacity?

Ok I would like to slightly change my question
I downloaded audacity 0.8 and it looks more primitive than I thought
actually I need the oldest version of audacity that allows me add some filter effects like noise cancellation, allow me to see the Fourier transform, both magnitude and phase, of the sound file
I want the to know the first version of Audacity that would allow me to do it, and would like to study the signal processing codes used if possible
Please let me know where I can find them
Thank you

All of the old releases are available here. http://sourceforge.net/projects/audacity/files/audacity/
As to which version, Noise Removal was in version 1.0. I don’t know earlier than that.

Thank you for the link
It seems Noise removal was included since 0.97 but few effects like filtering were available even before that
But the download page does not have a link to the source code
Where can I find the source code for ver 0.97?

Yes it does.

Download files available:

audacity-win-0_97.exe 2001-10-10 1.3 MB
audacity-win-0_97.zip 2001-10-10 1.0 MB
audacity-macosx-0.97.sit 2001-10-10 1.4 MB
audacity-mac-0.97.sit 2001-10-10 1.3 MB
audacity-0.97-1.i386.rpm 2001-10-10 517.1 kB
audacity-src-0.97.tgz 2001-10-10 1.8 MB