following: @code{general}, @code{float}, @code{system}, @code{vector},
@code{all}, @code{save}, @code{restore}.
+@item tui reg prev
+Show the previous register group. The list of register groups as well
+as their order is target specific. The predefined register groups are
+the following: @code{general}, @code{float}, @code{system},
+@code{vector}, @code{all}, @code{save}, @code{restore}.
+
@item tui reg system
Show the system registers in the register window.