Use backtick code blocks for syntax highlighting

11-04.md

@@ -15,12 +15,13 @@ AT clone to verify the basic functionality of the timer by measuring the
 performance of simple instruction sequences. I was cruising along with
 no problems until I timed the following code:
 
-
-        mov    cx,1000
-        call   ZTimerOn
-    LoopTop:
-        loop   LoopTop
-        call   ZTimerOff
+```nasm
+    mov    cx,1000
+    call   ZTimerOn
+LoopTop:
+    loop   LoopTop
+    call   ZTimerOff
+```
 
 ![**Figure 11.2**  *Word-aligned prefetching on the 286.*](images/11-02.jpg)
 
@@ -39,12 +40,14 @@ resided at the start of the next word-aligned word.
 One simple change brought the execution time down to a reasonable 12.5
 cycles per loop:
 
-      mov   cx,1000
-      call  ZTimerOn
-      even
-    LoopTop:
-      loop  LoopTop
-      call  ZTimerOff
+```nasm
+  mov   cx,1000
+  call  ZTimerOn
+  even
+LoopTop:
+  loop  LoopTop
+  call  ZTimerOff
+```
 
 While word-aligning branch destinations can improve branching
 performance, it's a nuisance and can increase code size a good deal, so
@@ -60,9 +63,11 @@ branch destination.
 I recommend that you only go out of your way to word-align the start
 offsets of your subroutines, as in:
 
-              even
-    FindChar  proc near
-              :
+```nasm
+          even
+FindChar  proc near
+          :
+```
 
 In my experience, this simple practice is the one form of code alignment
 that consistently provides a reasonable return for bytes and effort