\documentclass[fleqn,leqno]{article}
\usepackage{hypertlabook}
\pdftitle{ASCII Text}
\fixverbatim
\begin{popup}
\begin{verbatim*}
(***********************************************************
--algorithm HSClock {
  variable ca = [i \in 0..(N-1) |-> 0] ;

  process (Proc0 = 0) 
    { t: while (TRUE) 
          { await ca[0] = ca[N - 1] ;
            ca[0] := ca[0] (+) 1
          }
    }
     
  process (Proc \in 1..(N-1)) 
    { t: while (TRUE) 
          { await ca[self] # ca[self - 1] ;
            ca[self] := ca[self] (+) 1 
          }
    }
}
 ***********************************************************)
\end{verbatim*}
\end{popup}
\makeasciipopup