\topskip=0pt			% No extra space above
\output={\shipout\box255}	% Just ship out the box
\offinterlineskip		% we'll do the spacing outselves

\newdimen\rw \rw=2pt		% width of box rule
\newdimen\rs \rs=.1pt		% space between box and its contents
\newdimen\k  \k=2pt		% vertical space between char boxes

%
%  Put a box around something
%
\def\boxit#1%
{%
  \hbox
  {%
    \vrule width\rw
    \vbox
    {%
      \hrule height\rw
      \kern\rs
      \hbox{\kern\rs \hbox{#1}\kern\rs}%
      \kern\rs
      \hrule height\rw
    }%
    \vrule width\rw
  }%
}

\def\AddChar#1%
{%
  \ifx\relax#1\EndAdd\fi
  \setbox1=\hbox{$#1$}%
  \ifdim\ht1>8.5pt \dimen1=\ht1 \else \dimen1=8.5pt \fi
  \advance\dimen1 by \k
  \dimen0=\ht0 \advance\dimen0 by \dp0 \advance\dimen0 by \dimen1
  \immediate\write16
    {\the\dimen0 \space \the\ht1 \space \the\dp1 \space \the\wd1}%
  \setbox0=\vbox{\unvbox0\kern\k\hbox{\strut\unhbox1}}%
  \AddChar
}
\def\EndAdd\fi#1\AddChar{\fi}


\setbox0=\vbox{}
\immediate\write16{--start--}
\expandafter\AddChar\theChars\relax
\dimen0=\ht0 \advance\dimen0 by \dp0
\immediate\write16{\the\dimen0}
\immediate\write16{--end--}


\setbox1=\boxit{\box0}

%
%  Put box1 in the lower left hand corner of the page
%
\vbox to 0pt{\vskip10truein \vskip-\ht1 \kern-1pt
  \hbox to 0pt{\hskip-1truein \kern 1pt \box1\hss}\vss}

\end
