fpc/docs/go32ex/softint.tex

\begin{FPCList}
\item[Example]
\begin{verbatim}
Program softint;

uses go32;

var r : trealregs;

begin
     r.al := $01;
     realintr($21, r);
     Writeln('DOS v', r.al,'.',r.ah, ' detected');
end.\end{verbatim}
\end{FPCList}