Misc/abrash-black-book
Watch
1
0
Fork
You've already forked abrash-black-book
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Retidy, removing align=left from headings and empty paragraphs

Browse source
This commit is contained in:
James Gregory 2013-12-30 15:37:13 +11:00
commit a96a114403
362 changed files with 8472 additions and 5040 deletions
Download patch file Download diff file Expand all files Collapse all files

31
44-04.html
View file

@ -1,5 +1,4 @@
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
@ -19,17 +18,21 @@
<center>
<table border="1">
<tr>
<td><a href="44-03.html">Previous</a></td>
<td>
<a href="44-03.html">Previous</a>
</td>
<td><a href="index.html">Table of Contents</a></td>
<td>
<a href="index.html">Table of Contents</a>
</td>
<td><a href="44-05.html">Next</a></td>
<td>
<a href="44-05.html">Next</a>
</td>
</tr>
</table>
</center>
<p><br /></p>
<p>Listing 44.1 is written in C. It could equally well have been written in assembly language, and would then have been somewhat faster. However, wanted to make the point (as I&rsquo;ve made again and again) that assembly language, and, indeed, optimization in general, is needed only in the most critical portions of any program, and then only when the program would otherwise be too slow. Only in a highly performance-sensitive situation would the performance boost resulting from converting Listing 44.1 to assembly justify the time spent in coding and the bugs that would likely creep in&mdash;and the sample program already updates the screen at the maximum possible rate of once per frame even on a 1985-vintage 8-MHz AT. In this case, faster performance would result only in a longer wait for the page to flip.</p>
<h4 align="center" id="Heading5">Write Mode 3</h4>
@ -85,16 +88,20 @@ mov byte ptr es:[di],0ffh
<p>Each character in a font is represented by a pattern of bits, with 1-bits representing character pixels and 0-bits representing background pixels. Since we&rsquo;ll be using the 8x8 font stored in the BIOS ROM (a pointer to which can be obtained by calling a BIOS service, as illustrated by Listing 44.2), each character is exactly 8 bits, or 1 byte wide. We&rsquo;ll further insist that characters be placed on byte boundaries (that is, with their left edges only at pixels with X coordinates that are multiples of 8); this means that the character bytes in the font are automatically aligned with display memory, and no rotation or clipping of characters is needed. Finally, we&rsquo;ll draw all text in white.</p>
<p><br /></p>
<center>
<table border="1">
<tr>
<td><a href="44-03.html">Previous</a></td>
<td>
<a href="44-03.html">Previous</a>
</td>
<td><a href="index.html">Table of Contents</a></td>
<td>
<a href="index.html">Table of Contents</a>
</td>
<td><a href="44-05.html">Next</a></td>
<td>
<a href="44-05.html">Next</a>
</td>
</tr>
</table>
</center>