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+<appendix>
+<title>GO51...The 51 Column by 24 Line Video Display</title>
+<para>
+An alternative video screen device driver, which provides a 51
+column by 24 line display with upper and lower case character sets,
+can be incorporated into OS-9 with the command:
+<screen>
+GO51
+</screen>
+This command replaces the normal text screen driver with one that
+uses high resolution graphics to &quot;draw&quot; the characters. As there
+are fever pixels (dots) per character in this mode more characters
+can be displayed on the screen, albeit with some loss of character
+definition.
+</para>
+<para>
+Note, however, that the use of a high resolution graphics page
+means that an extra 6K bytes will be needed in this mode. This
+extra memory requirement is not normally a problem but in memory-critical
+applications, such as the C and Pascal compilers, the user
+can simply avoid the use of GO51.
+</para>
+<para>
+This mode of display has a set of <emphasis>escape sequences</emphasis>
+(commands) to
+emulate commercial data terminals. In addition to the video screen
+driver, GO51 provides a new keyboard driver which features auto-repeat.
+The keyboard code allocation is the same as described in
+section 2.4.3 and Appendix D.
+</para>
+<section>
+<title>The GO51 Display Functions</title>
+<para>
+Like the normal 32 by 16 video display functions described in
+Appendix C the 51 by 24 mode provides many built in facilities to
+control the display. These functions are activated by the use of
+the various escape sequences and control characters described below:
+</para>
+<informaltable frame="none">
+<tgroup cols="2">
+<colspec colwidth="1.5in">
+<colspec colwidth="3.5in">
+<thead>
+<row>
+<entry>Escape Sequence (Hex)</entry>
+<entry>Name/Function</entry>
+</row>
+</thead>
+
+<tbody>
+<row>
+<entry>1B 41 X Y</entry>
+<entry>CURSOR XY - move cursor to column X(0-50)
+and Y(0-23) where X and Y are single byte values.</entry>
+</row>
+<row>
+<entry>1B 42</entry>
+<entry>CLEAR EOL - clear from cursor to the end of
+line. Cursor position remains unchanged.</entry>
+</row>
+<row>
+<entry>1B 43</entry>
+<entry>CURSOR RIGHT - move cursor right by one character position.</entry>
+</row>
+<row>
+<entry>1B 44</entry>
+<entry>CURSOR UP - move cursor up by one line.</entry>
+</row>
+<row>
+<entry>1B 45</entry>
+<entry>CURSOR DOWN - move cursor down one line.</entry>
+</row>
+<row>
+<entry>1B 46</entry>
+<entry>REVERSE ON - turn reverse field on.</entry>
+</row>
+<row>
+<entry>1B 47</entry>
+<entry>REVERSE OFF - turn reverse field off.</entry>
+</row>
+<row>
+<entry>1B 48</entry>
+<entry>UNDERLINE ON - turn underline on.</entry>
+</row>
+<row>
+<entry>1B 49</entry>
+<entry>UNDERLINE OFF - turn underline off.</entry>
+</row>
+<row>
+<entry>1B 4A</entry>
+<entry>CLEAR EOS - clear from cursor to end of
+screen. Cursor position remains unchanged.</entry>
+</row>
+</tbody>
+</tgroup>
+</informaltable>
+
+
+
+
+<informaltable frame="none">
+<tgroup cols="2">
+<colspec colwidth="1.5in">
+<colspec colwidth="3.5in">
+<thead>
+<row>
+<entry>Control Character (Hex)</entry>
+<entry>Name/Function</entry>
+</row>
+</thead>
+<tbody>
+<row>
+<entry>07</entry>
+<entry>BELL - generates a short audible tone.</entry>
+</row>
+<row>
+<entry>08</entry>
+<entry>BACKSPACE (CURSOR LEFT) - moves cursor left one character position.</entry>
+</row>
+<row>
+<entry>0A</entry>
+<entry>LINE FEED - move cursor down by one line.</entry>
+</row>
+<row>
+<entry>0B</entry>
+<entry>CURSOR HOME - move cursor to home position 0,0 (top left).</entry>
+</row>
+<row>
+<entry>0C</entry>
+<entry>CLEAR SCREEN - clears the screen and home cursor.</entry>
+</row>
+</tbody>
+</tgroup>
+</informaltable>
+</section>
+</appendix>