\def\dumpfams{
	\dumpfam0	\dumpfam1	\dumpfam2	\dumpfam3
	\dumpfam4	\dumpfam5	\dumpfam6	\dumpfam7
	\dumpfam8	\dumpfam9	\dumpfam{A}	\dumpfam{B}
	\dumpfam{C}	\dumpfam{D}	\dumpfam{E}	\dumpfam{F}
}

\def\print#1{\hbox{#1}\hfil\break}

\let\EA\expandafter
\parindent0pt
\newcount \cfd
\newcount \numdims
\newif\ifprint
\def\dumpfam#1{
  \cfd = 0
  \print{~}
  \print{Family #1, textskewchar=\the\skewchar\textfont"#1,
scriptskewchar=\the\skewchar\scriptfont"#1, scriptscriptskewchar=\the\skewchar\scriptscriptfont"#1   }%
  \numdims=7
  \ifnum"#1 = 2 \numdims=22 \fi
  \ifnum"#1 = 3 \numdims=13 \fi
  \loop \ifnum\cfd < \numdims
    \advance\cfd 1
    \batchmode
    \edef\tvalue{\the\fontdimen\cfd\textfont"#1 }%
    \edef\svalue{\the\fontdimen\cfd\scriptfont"#1 }%
    \edef\xvalue{\the\fontdimen\cfd\scriptscriptfont"#1 }%
    \errorstopmode
     \printfalse
     \ifdim\tvalue>0pt        \printtrue     \fi
     \ifdim\svalue>0pt        \printtrue     \fi
     \ifdim\xvalue>0pt        \printtrue     \fi
    \ifprint
    \print{Dimen \the\cfd: text=\tvalue, script=\svalue, scriptscript=\xvalue}%
    \fi
  \repeat
}

\expandafter\ifx\csname contextversion\endcsname\relax \else
 \switchtobodyfont[10pt]
\fi
$  \dumpfams $
\bye