--- a/slideshow.tex	Tue Jan 15 03:03:10 2008 -0500
+++ b/slideshow.tex	Tue Jan 15 03:31:51 2008 -0500
@@ -101,6 +101,65 @@
 	\end{itemstep}
 \end{slide}}
 
+\overlays{1}{
+\begin{slide}{?. Architecture Modes}
+	\begin{itemize}
+		\item 2 supported modes
+		\item ESA/390
+		\begin{itemize}
+			\item 31-bit addressing
+			\item 32-bit arithmetic
+		\end{itemize}
+		\item z/Architecture
+		\begin{itemize}
+			\item 64-bit addressing
+			\item 64-bit arithmetic
+		\end{itemize}
+		\item Switch between modes at run time
+	\end{itemize}
+\end{slide}}
+
+\overlays{1}{
+\begin{slide}{?. Registers}
+	\begin{itemize}
+		\item 16 General purpose registers (64/32-bit)
+		\item 16 Floating point registers (64-bit)
+		\item 16 Access registers (32-bit)
+		\item 16 Control registers (64/32-bit)
+		% floating point control register
+		% prefix register
+		% PSW
+	\end{itemize}
+\end{slide}}
+
+\overlays{1}{
+\begin{slide}{?. Instruction Set}
+	\begin{itemize}
+		\item CISC architecture
+		\begin{itemize}
+			\item Complex Instruction Set Computer
+			\item System/360 (November 1970) had 143 instructions
+			\item z9 (September 2005) describes 689 instructions
+			\begin{itemize}
+				\item 41 variations of ADD
+			\end{itemize}
+		\end{itemize}
+		\item Instructions are always...
+		\begin{itemize}
+			\item 2, 4, or 6 bytes long
+			\item Aligned on 2-byte boundary
+		\end{itemize}
+		\item Many instructions reference storage
+	\end{itemize}
+\end{slide}}
+
+% 4) 3 addressing modes
+% 5) interrupts
+% 8) specs
+% 9)
+% 10)
+% 11)
+
 %%% Channels
 \overlays{6}{
 \begin{slide}{?. Channels}
@@ -194,16 +253,6 @@
 	}
 \end{slide}}
 
-% 3) lots of registers
-% 4) 3 addressing modes
-% 5) interrupts
-% 6) instruction set (memory happy, instruction counts)
-% 7) arch modes
-% 8) specs
-% 9)
-% 10)
-% 11)
-
 %%% SIE
 \overlays{1}{
 \begin{slide}{?. SIE}