\renewcommand\chapterillustration{systemsetup/six-computers-chips-circuits}
%\setcounter{chapter}{3}
\chapter{repositories}

\section*{enable contrib and non-free}

\begin{shell}{caption=enable all repositories, label=lst:repositories}
~ $ sed -i "/etc/apt/sources.list" -e "s/^\(deb.*\) main$/\1 main contrib non-free/"
\end{shell}

\section*{enable unstable}
\begin{shell}{}
cat > /etc/apt/sources.list.d/unstable.list <<EOF
deb http://http.debian.net/debian/ unstable main non-free contrib
deb-src http://http.debian.net/debian/ unstable main non-free contrib
EOF

cat > /etc/apt/preferences.d/unstable <<EOF
Package: *
Pin: release o=Debian,a=unstable
Pin-Priority: 200
EOF
# APT::Default-Release "testing"; > /etc/apt/apt.conf.d/00local

apt-get update
\end{shell}

\section*{enable experimental}
\begin{shell}{}
cat > /etc/apt/sources.list.d/experimental.list <<EOF
deb http://http.debian.net/debian/ experimental main non-free contrib
deb-src http://http.debian.net/debian/ experimental main non-free contrib
EOF

cat > /etc/apt/preferences.d/experimental <<EOF
Package: *
Pin: release o=Debian,a=experimental
Pin-Priority: 10
EOF

apt-get update
\end{shell}

\section*{install base backages}
\begin{shell}{}
apt-get -y --install-recommends install firmware-linux
\end{shell}
Foo