calc-bin.el (calc-radix): Have the O option turn on twos-complement mode.

doc/misc/ChangeLog

+2010-04-18  Jay Belanger  <jay.p.belanger@gmail.com>
+
+	* calc.texi (Radix modes): Mention that the option prefix will
+	turn on twos-complement mode.
+	(Inverse and Hyperbolic Flags): Mention the Option flag.
+
 2010-04-15  Carsten Dominik  <carsten.dominik@gmail.com>
 
 	* org.texi (LaTeX and PDF export): Add a footnote about xetex.

doc/misc/calc.texi

@@ -12289,15 +12289,21 @@ may be executed with @kbd{x} or @kbd{M-x}.  Their effect is simply to
 toggle the Inverse and/or Hyperbolic flags and then execute the
 corresponding base command (@code{calc-sin} in this case).
-The Inverse and Hyperbolic flags apply only to the next Calculator
-command, after which they are automatically cleared.  (They are also
-cleared if the next keystroke is not a Calc command.)  Digits you
-type after @kbd{I} or @kbd{H} (or @kbd{K}) are treated as prefix
-arguments for the next command, not as numeric entries.  The same
-is true of @kbd{C-u}, but not of the minus sign (@kbd{K -} means to
-subtract and keep arguments).
-
-The third Calc prefix flag, @kbd{K} (keep-arguments), is discussed
+@kindex O
+@pindex calc-option
+The @kbd{O} key (@code{calc-option}) sets another flag, the
+@dfn{Option Flag}, which also can alter the subsequent Calc command in
+various ways. 
+
+The Inverse, Hyperbolic and Option flags apply only to the next
+Calculator command, after which they are automatically cleared.  (They
+are also cleared if the next keystroke is not a Calc command.)  Digits
+you type after @kbd{I}, @kbd{H} or @kbd{O} (or @kbd{K}) are treated as
+prefix arguments for the next command, not as numeric entries.  The
+same is true of @kbd{C-u}, but not of the minus sign (@kbd{K -} means
+to subtract and keep arguments).
+
+Another Calc prefix flag, @kbd{K} (keep-arguments), is discussed
 elsewhere.  @xref{Keep Arguments}.
 @node Calculation Modes, Simplification Modes, Inverse and Hyperbolic, Mode Settings
@@ -13175,12 +13181,13 @@ in the current radix.  (Larger integers will still be displayed in their
 entirety.) 
 @cindex Two's complements
-With the binary, octal and hexadecimal display modes, Calc can
-display @expr{w}-bit integers using two's complement notation.  This
-option is selected with the key sequences @kbd{C-u d 2}, @kbd{C-u d 8}
-and @kbd{C-u d 6}, respectively, and a negative word size might be
-appropriate (@pxref{Binary Functions}). In two's complement 
-notation, the integers in the (nearly) symmetric interval from
+Calc can display @expr{w}-bit integers using two's complement
+notation, although this is most useful with the binary, octal and
+hexadecimal display modes.  This option is selected by using the
+@kbd{O} option prefix before setting the display radix, and a negative word
+size might be appropriate (@pxref{Binary Functions}). In two's
+complement notation, the integers in the (nearly) symmetric interval
+from
 @texline @math{-2^{w-1}}
 @infoline @expr{-2^(w-1)}
 to
@@ -35461,6 +35468,7 @@ keystrokes are not listed in this summary.
 @r{       @:      M     @:             @:        @:calc-more-recursion-depth@:}
 @r{       @:    I M     @:             @:        @:calc-less-recursion-depth@:}
 @r{      a@:      N     @:             @:     5  @:evalvn@:(a)}
+@r{       @:      O     @:command      @:    32  @:@:Option}
 @r{       @:      P     @:             @:        @:@:pi}
 @r{       @:    I P     @:             @:        @:@:gamma}
 @r{       @:    H P     @:             @:        @:@:e}

lisp/ChangeLog

+2010-04-18  Jay Belanger  <jay.p.belanger@gmail.com>
+
+	* calc.el (calc-mode-map): Bind "O" to `calc-missing-key'.
+
+	* calc-bin.el (calc-radix): Have the "O" option turn on
+	twos-complement mode.
+
 2010-04-17  Jay Belanger  <jay.p.belanger@gmail.com>
 
 	* calc-ext.el (calc-init-extensions): Add keybinding for 'calc-option'.

lisp/calc/README

@@ -72,6 +72,12 @@ opinions.
 Summary of changes to "Calc"
 ------- -- ------- --  ----
 
+Emacs 24.1
+
+* Added "O" option prefix.
+
+* Used "O" prefix to "d r" (`calc-radix') to turn on twos-complement mode.
+
 Emacs 23.2
 
 * Added twos-complement display.

lisp/calc/calc-bin.el

@@ -175,7 +175,7 @@ the size of a Calc bignum digit.")
        (progn
 	 (calc-change-mode 
           (list 'calc-number-radix 'calc-twos-complement-mode)
-          (list n (and (or (= n 2) (= n 8) (= n 16)) arg)) t)
+          (list n (or arg (calc-is-option))) t)
 	 ;; also change global value so minibuffer sees it
 	 (setq-default calc-number-radix calc-number-radix))
      (setq n calc-number-radix))