Normal quotes

33-02.md

@@ -4,8 +4,8 @@
 
 #### Color Paging with the Color Select Register {#Heading6}
 
-“Wait a minute,” you say bemusedly. “Aren’t you missing some bits
-between the palette RAM and the DAC?” Indeed I am. The palette RAM puts
+"Wait a minute," you say bemusedly. "Aren't you missing some bits
+between the palette RAM and the DAC?" Indeed I am. The palette RAM puts
 out 6 bits at a time, and the DAC takes in 8 bits at a time. The two
 missing bits—bits 6 and 7 going into the DAC—are supplied by bits 2 and
 3 of the Color Select register (Attribute Controller register 14H). This
@@ -15,34 +15,34 @@ of 64 attributes. Normally, those 64 attributes look up colors from
 registers 0 through 63 in the DAC, because bits 2 and 3 of the Color
 Select register are both zero. By changing the Color Select register,
 however, one of three other 64 color sets can be selected instantly.
-I’ll refer to the process of flipping through color sets in this manner
+I'll refer to the process of flipping through color sets in this manner
 as *color paging*.
 
-That’s interesting, but frankly it seems somewhat half-baked; why bother
+That's interesting, but frankly it seems somewhat half-baked; why bother
 expanding 16 attributes to 64 attributes before looking up the colors in
-the DAC? What we’d *really* like is to map the 16 attributes straight
+the DAC? What we'd *really* like is to map the 16 attributes straight
 through the palette RAM without changing them and supply the upper *4*
 bits going to the DAC from a register, giving us 16 color pages. As it
 happens, all we have to do to make that happen is set bit 7 of the
-Attribute Controller Mode register (register 10H) to 1. Once that’s
+Attribute Controller Mode register (register 10H) to 1. Once that's
 done, bits 0 through 3 of the Color Select register go straight to bits
 4 through 7 of the DAC, and only bits 3 through 0 coming out of the
 palette RAM are used; bits 4 and 5 from the palette RAM are ignored. In
 this mode, the palette RAM effectively contains 4-bit, rather than
-6-bit, registers, but that’s no problem because the palette RAM will be
+6-bit, registers, but that's no problem because the palette RAM will be
 programmed to pass pixel values through unchanged by having register 0
 set to 0, register 1 set to 1, and so on, a configuration in which the
 upper two bits of all the palette RAM registers are the same (zero) and
-therefore irrelevant. As a matter of fact, you’ll generally want to set
+therefore irrelevant. As a matter of fact, you'll generally want to set
 the palette RAM to this pass-through state when working with VGA color,
-whether you’re using color paging or not.
+whether you're using color paging or not.
 
 Why is it a good idea to set the palette RAM to a pass-through state?
-It’s a good idea because the palette RAM is programmed by the BIOS to
+It's a good idea because the palette RAM is programmed by the BIOS to
 EGA-compatible settings and the first 64 DAC registers are programmed to
 emulate the 64 colors that an EGA can display during mode sets for
 16-color modes. This is done for compatibility with EGA programs, and
-it’s useless if you’re going to tinker with the VGA’s colors. As a VGA
+it's useless if you're going to tinker with the VGA's colors. As a VGA
 programmer, you want to take a 4-bit pixel value and turn it into an
 18-bit RGB value; you can do that without any help from the palette RAM,
 and setting the palette RAM to pass-through values effectively takes it
@@ -52,16 +52,16 @@ that I know of for VGA-only color programming.
 
 #### 256-Color Mode {#Heading7}
 
-So far I’ve spoken only of 16-color modes; what of 256-color modes?
+So far I've spoken only of 16-color modes; what of 256-color modes?
 
-The rule in 256-color modes is: *Don’t tinker with the VGA palette*.
+The rule in 256-color modes is: *Don't tinker with the VGA palette*.
 Period. You can select any colors you want by reprogramming the DAC, and
-there’s no guarantee as to what will happen if you mess around with the
-palette RAM. There’s no benefit that I know of to changing the palette
-RAM in 256-color mode, and the effect may vary from VGA to VGA. So don’t
-do it unless you know something I don’t.
+there's no guarantee as to what will happen if you mess around with the
+palette RAM. There's no benefit that I know of to changing the palette
+RAM in 256-color mode, and the effect may vary from VGA to VGA. So don't
+do it unless you know something I don't.
 
-On the other hand, feel free to alter the DAC settings to your heart’s
+On the other hand, feel free to alter the DAC settings to your heart's
 content in 256-color mode, all the more so because this is the only mode
 in which all 256 DAC settings can be displayed simultaneously. By the
 way, the Color Select register and bit 7 of the Attribute Controller
@@ -77,8 +77,8 @@ interrupt 10H, function 10H. I strongly recommend using the BIOS
 interrupt; a clone BIOS may mask incompatibilities with genuine IBM
 silicon. Such incompatibilities could include anything from flicker to
 trashing the palette RAM; or they may not exist at all, but why find out
-the hard way? My policy is to use the BIOS unless there’s a clear reason
-not to do so, and there’s no such reason that I know of in this case.
+the hard way? My policy is to use the BIOS unless there's a clear reason
+not to do so, and there's no such reason that I know of in this case.
 
 When programming specifically for the VGA, the palette RAM needs to be
 loaded only once, to store the pass-through values 0 through 15 in
@@ -91,7 +91,7 @@ bytes pointed to by ES:DX, with ES:DX pointing to the value for register
 ES:DX+16, which points to the overscan value. The palette RAM registers
 store 6 bits each, so only the lower 6 bits of each of the first 16
 bytes in the 17-byte block are significant. (The Overscan register,
-which specifies what’s displayed between the area of the screen that’s
+which specifies what's displayed between the area of the screen that's
 controlled by the values in display memory and the blanked region at the
 edges of the screen, is an 8-bit register, however.)
 
@@ -100,7 +100,7 @@ Alternatively, any one palette RAM register can be set via subfunction 0
 BL contains the number of the palette RAM register to set and the lower
 6 bits of BH contain the value to which to set that register.
 
-Having said that, let’s leave the palette RAM behind (presumably in a
+Having said that, let's leave the palette RAM behind (presumably in a
 pass-through state) and move on to the DAC, which is the right place to
 do color translation on the VGA.