\newcount \Re \newcount \Im
\newcount \Zr \newcount \Zi \newcount \Zrr \newcount \Zii \newcount \Ind

\newcommand{\MandIter}{%
\divide \Zr by 16 \divide \Zi by 16
\Zrr=\Zr \multiply \Zrr by \Zrr \divide \Zrr by 256
\Zii=\Zi \multiply \Zii by \Zii \divide \Zii by 256
\multiply \Zi by \Zr \divide \Zi by 256
\multiply \Zi by 2 \advance \Zi by \Im
\let\next=\MandIter
\ifnum \count4>262144 \let\next=\relax \fi
\ifnum \Ind=15 \let\next=\relax \else \advance \Ind by 1 \fi
\next
}

\newcommand{\MandLoop}{%
\Re=\count0
\multiply \Re by 196608 \divide \Re by \count2 \advance \Re by -131072
\Im=\count1
\multiply \Im by 150000 \divide \Im by \count3 \advance \Im by -75000
\Zr=\Re \Zi=\Im \Ind=0
\MandIter
\ifcase \Ind
.\or .\or :\or -\or +\or =\or *\or i\or I%
\or H\or O\or X\or M\or \#\or @\or .%
\fi
\let\next=\MandLoop
\ifnum \count0>\count2
\newline
\count0=0
\ifnum \count1>\count3
\let\next=\relax
\fi
\fi
\next
}

\newcommand{\Mandel}[2]{
\count0=0 \count1=0 \count2=#1 \count3=#2
\MandLoop
}

% Document
% --------
\documentclass[a4paper]{article}

\setlength{\parindent}{0pt}
\setlength{\oddsidemargin}{0pt}
\setlength{\topmargin}{0pt}

\begin{document}
\ttfamily
\setlength{\baselineskip}{0pt}
{\small
\Mandel{100}{60}
}
\end{document}


(Snapshot from ghostview)