Commit 0e983327 by Jay Belanger

### (Radix Modes): Clarify two's complement notation.

parent fd471993
 2009-12-15 Jay Belanger * calc/calc.texi (Radix Modes): Clarify two's complement notation. 2009-12-14 Chong Yidong * sem-user.texi (Semantic mode, Idle Scheduler, Smart Completion) ... ...
 ... ... @@ -13173,34 +13173,36 @@ are displayed with at least enough digits to represent in the current radix. (Larger integers will still be displayed in their entirety.) Calc can display @expr{w}-bit integers using two's complement notation and binary, octal or hexadecimal display radix with the commands @kbd{C-u d 2}, @kbd{C-u d 8} or @kbd{C-u d 6}, respectively. In this case a negative word size might be appropriate (@pxref{Binary Functions}). The integers in the symmetric interval from @cindex Two's complements With the binary, octal and hexadecimal display modes, Calc can display @expr{w}-bit integers using two's complement notation. These versions of the display radices are selected with the key sequences @kbd{C-u d 2}, @kbd{C-u d 8} and @kbd{C-u d 6}, respectively. In these cases 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 @texline @math{2^{w-1}-1} @infoline @expr{2^(w-1)-1} will be represented by using the integers from @expr{0} to @expr{2^w}; are represented by the integers from @expr{0} to @expr{2^w-1}: the integers from @expr{0} to @texline @math{2^{w-1}-1} @infoline @expr{2^(w-1)-1} will be represented by themselves and the integers from are represented by themselves and the integers from @texline @math{-2^{w-1}} @infoline @expr{-2^(w-1)} to @expr{-1} will have @expr{2^w} added to them, so they will be represented by the integers from to @expr{-1} are represented by the integers from @texline @math{2^{w-1}} @infoline @expr{2^(w-1)} to @expr{2^w}. Calc will represent a twos-complement integer by the radix (either @expr{2}, @expr{8} or @expr{16}), two @kbd{#} symbols, and then the digits (including any necessary leading zeros to include all @expr{w} bits). Numbers that are not displayed in twos-complement notation (i.e., that aren't integers from to @expr{2^w-1} (the integer @expr{k} is represented by @expr{k+2^w}). Calc will display a two's complement integer by the radix (either @expr{2}, @expr{8} or @expr{16}), two @kbd{#} symbols, and then its representation (including any leading zeros necessary to include all @expr{w} bits). In a two's complement display mode, numbers that are not displayed in two's complement notation (i.e., that aren't integers from @texline @math{-2^{w-1}} @infoline @expr{-2^(w-1)} to
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