Normal quotes

45-04.md

@@ -2,11 +2,11 @@
   [Previous](45-03.html)   [Table of Contents](index.html)   [Next](45-05.html)
   ------------------------ --------------------------------- --------------------
 
-One point I’d like to make is that although the system-memory buffer in
+One point I'd like to make is that although the system-memory buffer in
 Listing 45.1 has exactly the same dimensions as the screen bitmap,
-that’s not a requirement, and there are some good reasons not to make
+that's not a requirement, and there are some good reasons not to make
 the two the same size. For example, if the system buffer is bigger than
-the area displayed on the screen, it’s possible to pan the visible area
+the area displayed on the screen, it's possible to pan the visible area
 around the system buffer. Or, alternatively, the system buffer can be
 just the size of a desired window, representing a window into a larger,
 virtual buffer. We could then draw the desired portion of the virtual
@@ -18,31 +18,31 @@ location.
   ![](images/i.jpg)   *Another argument in favor of a small viewing window is that it restricts the amount of display memory actually drawn to. Restricting the display memory used for animation reduces the total number of display-memory accesses, which in turn boosts overall performance; it also improves the performance and appearance of panning, in which the whole window has to be redrawn or copied.*
   ------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 
-If you keep a close watch, you’ll notice that many high-performance
+If you keep a close watch, you'll notice that many high-performance
 animation games similarly restrict their full-featured animation area to
-a relatively small region. Often, it’s hard to tell that this is the
+a relatively small region. Often, it's hard to tell that this is the
 case, because the animation region is surrounded by flashy digitized
 graphics and by items such as scoreboards and status screens, but look
-closely and see if the animation region in your favorite game isn’t
+closely and see if the animation region in your favorite game isn't
 smaller than you thought.
 
 ### Hi-Res VGA Page Flipping {#Heading8}
 
 On a standard VGA, hi-res mode is mode 12H, which offers 640x480
-resolution with 16 colors. That’s a nice mode, with plenty of pixels,
+resolution with 16 colors. That's a nice mode, with plenty of pixels,
 and square ones at that, but it lacks one thing—page flipping. The
 problem is that the mode 12H bitmap is 150 K in size, and the standard
 VGA has only 256 K total, too little memory for two of those monster
 mode 12H pages. With only one page, flipping is obviously out of the
-question, and without page flipping, top-flight, hi-res animation can’t
-be implemented. The standard fallback is to use the EGA’s hi-res mode,
+question, and without page flipping, top-flight, hi-res animation can't
+be implemented. The standard fallback is to use the EGA's hi-res mode,
 mode 10H (640x350, 16 colors) for page flipping, but this mode is less
 than ideal for a couple of reasons: It offers sharply lower vertical
-resolution, and it’s lousy for handling scaled-up CGA graphics, because
+resolution, and it's lousy for handling scaled-up CGA graphics, because
 the vertical resolution is a fractional multiple—1.75 times, to be
 exact—of that of the CGA. CGA resolution may not seem important these
 days, but many images were originally created for the CGA, as were many
-graphics packages and games, and it’s at least convenient to be able to
+graphics packages and games, and it's at least convenient to be able to
 handle CGA graphics easily. Then, too, 640x350 is also a poor multiple
 of the 200 scan lines of the popular 320x200 256-color mode 13H of the
 VGA.
@@ -51,7 +51,7 @@ There are a couple of interesting, if imperfect, solutions to the
 problem of hi-res page flipping. One is to use the split screen to
 enable page flipping only in the top two-thirds of the screen; see the
 previous chapter for details, and for details on the mechanics of page
-flipping generally. This doesn’t address the CGA problem, but it does
+flipping generally. This doesn't address the CGA problem, but it does
 yield square pixels and a full 640x480 screen resolution, although not
 all those pixels are flippable and thus animatable.
 
@@ -70,14 +70,14 @@ The key to 640x400 mode is understanding that on a VGA, mode 10H
 (640x350) is, at heart, a 400-scan-line mode. What I mean by that is
 that in mode 10H, the Vertical Total register, which controls the total
 number of scan lines, both displayed and nondisplayed, is set to 447,
-exactly the same as in the VGA’s text modes, which do in fact support
+exactly the same as in the VGA's text modes, which do in fact support
 400 scan lines. A properly sized and centered display is achieved in
 mode 10H by setting the polarity of the sync pulses to tell the monitor
 to scan vertically at a faster rate (to make fewer lines fill the
 screen), by starting the overscan after 350 lines, and by setting the
 vertical sync and blanking pulses appropriately for the faster vertical
-scanning rate. Changing those settings is all that’s required to turn
-mode 10H into a 640x400 mode, and that’s easy to do, as illustrated by
+scanning rate. Changing those settings is all that's required to turn
+mode 10H into a 640x400 mode, and that's easy to do, as illustrated by
 Listing 45.2, which provides mode set code for 640x400 mode.
 
 **LISTING 45.2 L45-2.C**