Ungefähr so?
\documentclass{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\shade[ball color=black,clip] (0,0) circle (4.5em);
\foreach \x in {-5,...,5} {
\foreach \y in {-5,...,5} {
\pgfmathsetmacro\txt{random(0,1)}
\node[green,font=\ttfamily] at (\x em,\y em) (\x*1em,\y*1em) {\txt};
}
}
\end{tikzpicture}
\end{document}
> ![alt text][1]
[1]: http://texwelt.de/wissen/upfiles/u_175.png
