The PostgreSQL 8.2rc1 sources can be obtained by anonymous FTP from ftp://ftp.postgresql.org/pub/source/v8.2rc1/postgresql-8.2rc1.tar.gz. Other download options can be found on our website: http://www.postgresql.org/download/. After you have obtained the file, unpack it:
gunzip postgresql-8.2rc1.tar.gz
tar xf postgresql-8.2rc1.tar
This will create a directory
postgresql-8.2rc1
under the current directory
with the PostgreSQL sources.
Change into that directory for the rest
of the installation procedure.