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 <P>&#147;That&#146;s an interesting application of write mode 2,&#148; you may well say, &#147;but is it really useful?&#148; While the ability to convert chunky bitmaps into VGA bitmaps does have its uses, Listing 27.1 is primarily intended to illustrate the mechanics of write mode 2.
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-<TABLE WIDTH="100%"><TD WIDTH="5%" VALIGN="TOP"><IMG SRC="images/27-02i.jpg"><TD WIDTH="95%"><SMALL><I>For performance, it&#146;s best to store 16-color bitmaps in pre-separated four-plane format in system memory, and copy one plane at a time to the screen. Ideally, such bitmaps should be copied one scan line at a time, with all four planes completed for one scan line before moving on to the next. I say this because when entire images are copied one plane at a time, nasty transient color effects can occur as one plane becomes visibly changed before other planes have been modified.</I></SMALL>
+<TABLE WIDTH="100%"><TD WIDTH="5%" VALIGN="TOP"><IMG SRC="images/i.jpg"><TD WIDTH="95%"><SMALL><I>For performance, it&#146;s best to store 16-color bitmaps in pre-separated four-plane format in system memory, and copy one plane at a time to the screen. Ideally, such bitmaps should be copied one scan line at a time, with all four planes completed for one scan line before moving on to the next. I say this because when entire images are copied one plane at a time, nasty transient color effects can occur as one plane becomes visibly changed before other planes have been modified.</I></SMALL>
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 <H4 ALIGN="LEFT"><A NAME="Heading6"></A><FONT COLOR="#000077">Drawing Color-Patterned Lines Using Write Mode 2</FONT></H4>
 <P>A more serviceable use of write mode 2 is shown in the program presented in Listing 27.2. The program draws multicolored horizontal, vertical, and diagonal lines, basing the color patterns on passed color tables. Write mode 2 is ideal because in this application color can vary from one pixel to the next, and in write mode 2 all that&#146;s required to set pixel color is a change of the lower nibble of the byte written by the CPU. Set/reset could be used to achieve the same result, but an index/data pair of <B>OUT</B>s would be required to set the Set/Reset register to each new color. Similarly, the Map Mask register could be used in write mode 0 to set pixel color, but in this case not only would an index/data pair of <B>OUT</B>s be required but there would also be no guarantee that data already in display memory wouldn&#146;t interfere with the color of the pixel being drawn, since the Map Mask register allows only selected planes to be drawn to.</P>