%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 8-5-2 on page 575.
%% 
%%  Copyright (C) 2007 Michel Goossens, Frank Mittelbach, Denis Roegel, Sebastian Rahtz, Herbert 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.
%% 

\documentclass{ttctexa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{427.6677pt}

\StartShownPreambleCommands

\StopShownPreambleCommands
\begin{document}
\newfont{\timon}{timing1 scaled 800}
\newfont{\timtw}{timing2 scaled 800}
\newfont{\timons}{timing1s scaled 800}
\newfont{\timtws}{timing2s scaled 800}
\newcommand{\TTT}[3]{\rule[-3mm]{0pt}{8mm}\texttt{#1} & #2 & \texttt{#3}
                    $\to$&\TTTT{#3}}
\newcommand{\TTTT}[1]{\raisebox{-2mm}{\timon #1}&%
  \raisebox{-2mm}{\timons #1}&%
  \raisebox{-2mm}{\timtw #1}&%
  \raisebox{-2mm}{\timtws #1}}
\begin{tabular}{@{}cllcccc@{}}
&&& \multicolumn{4}{c}{\itshape Font Variants} \\
\emph{Letter} & \multicolumn{1}{c}{\emph{Symbol}}  &      &\ttfamily 1&\ttfamily 1s&\ttfamily 2 &\ttfamily 2s
                                              \\\hline
\TTT{L}{Low level}{HLLLLH}                     \\[-1.7pt]
\TTT{H}{High level}{LHHHHL}                    \\[-1.7pt]
\TTT{F}{Floating line (unknown level)}{LFFFFH} \\[-1.7pt]
\TTT{l}{Low level with marks}{hllllh}          \\[-1.7pt]
\TTT{h}{High level with marks}{lhhhhl}         \\[-1.7pt]
\TTT{.}{Empty line with marks}{......}         \\[-1.7pt]
\TTT{V}{Valid bus}{ZVVVVU}                     \\[-1.7pt]
\TTT{X}{Bus with change of state}{VVVXVV}      \\[-1.7pt]
\TTT{U}{Invalid bus}{ZUUUUV}                   \\[-1.7pt]
\TTT{Z}{Tristate}{VZZZZU}                      \\[-1.7pt]
\TTT{T}{Top line with time mark}{TtttTt}       \\[-1.7pt]
\TTT{t}{Top line without time mark}{TtTtTt}    \\[-1.7pt]
\TTT{B}{Bottom line with time mark}{BbbbBb}    \\[-1.7pt]
\TTT{b}{Bottom line without time mark}{BbBbBb} \\[-1.7pt]
\TTT{-}{Interruption sign}{UUU-UU}             \\\hline
\end{tabular}
\end{document}