\documentclass[fleqn,leqno]{article}
\usepackage{hypertlabook}
\pdftitle{ASCII Text}
\fixverbatim
\begin{popup}
\begin{verbatim*}
    BY <2>1, <2>2, GCD3 DEF Inv, TypeOK, GCDInv, Next
\end{verbatim*}
\end{popup}
\makeasciipopup