add notes to archman

diff --git a/doc/archman.tex b/doc/archman.tex
index 06798bf..707e71a 100644 (file)
--- a/doc/archman.tex
+++ b/doc/archman.tex
@@ -287,3 +287,42 @@ Note how a ``standing'' instruction is encoded as {\tt Count=1111111}
 
 \end{itemize}
 
+\pagebreak
+\section{Future Directions}
+
+Looking back on the design of the pump, several things are now
+apparent which were not initially.  In particular, it seems that it
+could be useful to separate {\it loading the count register} from
+other types of instructions.  This would have a few advantages:
+
+\begin{itemize}
+\item The size of the count field would not be a consideration in the
+      ``instruction budget'' of normal execution instructions
+\item It would be possible to have finitely-repeating,
+      infinitely-requeueing instructions (FIXME).
+\end{itemize}
+
+\begin{verbatim}
+essence of the pump:
+
+ti
+di
+
+dc (data capture)
+dl (data literal, take from instruction bits)
+
+di
+doi (data output, destination taken from instruction)
+dod (data output, destination taken from Data register)
+
+set count
+decrement count
+
+requeue if count>0
+requeue unconditionally
+repeat  if count>0
+repeat  unconditionally
+
+\end{verbatim}
+
+