%% 
%%  An UIT Edition example
%% 
%%  Example 04-24-2 on page 134.
%% 
%%  Copyright (C) 2012 Vo\ss 
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 

% Show page(s) 1,2

%% ==== 
\PassOptionsToClass{}{beamer}
\documentclass{exabeamer}
\usepackage[utf8]{inputenc}

%\StartShownPreambleCommands
\usepackage{pgfpages} \setbeameroption{previous slide on second screen=left}
%\StopShownPreambleCommands

\begin{document}
\begin{frame}[t]{Output on two screens}
An example use of AWK:

\begin{enumerate}[<+->] \ttfamily\small
\item AWK=`which gawk` || AWK=`which awk`
\item \$AWK -f undo-bibtex-linebreaks.awk \$MAIN.bbl > \$MAIN.bbl-tmp
\item mv \$MAIN.bbl-tmp \$MAIN.bbl
\end{enumerate}

\vfill The left side shows the previous overlay.
\end{frame}
\end{document}