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The gfx module is now in a seperate file
author roug
date Tue, 04 Mar 2003 20:07:34 +0000
parents d9ed9d44b70c
children df32e1597294
files docs/basic09/basic09.docbook docs/basic09/gfx.appendix
diffstat 2 files changed, 421 insertions(+), 413 deletions(-) [+]
line wrap: on
line diff
--- a/docs/basic09/basic09.docbook	Tue Mar 04 20:05:50 2003 +0000
+++ b/docs/basic09/basic09.docbook	Tue Mar 04 20:07:34 2003 +0000
@@ -1,9 +1,15 @@
 <?xml version="1.0" ?>
 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
    "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
-  <!ENTITY b09 "BASIC09">
-  <!ENTITY mdash   "&#8212;">
-  <!ENTITY gfx2app       SYSTEM "gfx2.appendix">
+  <!ENTITY b09           "BASIC09">
+  <!ENTITY CPU           "6809">
+  <!ENTITY os9level      "OS-9 Level One">
+  <!ENTITY os9version    "Version 02.01.01 BETA1">
+  <!ENTITY vendor        "The CoCo Community">
+  <!ENTITY make          "TRS-80/Tandy Color Computer">
+  <!ENTITY mdash          "&#8212;">
+  <!ENTITY gfxapp       SYSTEM "gfx.appendix">
+  <!ENTITY gfx2app      SYSTEM "gfx2.appendix">
 ]>
 <book id="basic09" lang="en">
  <bookinfo>
@@ -13,7 +19,7 @@
 
 <copyright>
 <year>1983</year>
-<holder>Dragon Data Ltd. and Microware Systems Corporation.
+<holder>Microware Systems Corporation.
 All Rights Reserved.
 Basic 09 is a trademark of Microware Systems Corporation and Motorola Inc.
 </holder>
@@ -21,8 +27,9 @@
 </copyright>
 <revhistory>
 <revision>
-<revnumber>F</revnumber>
-<date>February 1983</date>
+<revnumber>A</revnumber>
+<date>March 2003</date>
+<revremark>Updated for OS-9 Level One Version 02.01.01</revremark>
 </revision>
 </revhistory>
 </bookinfo>
@@ -36,8 +43,8 @@
 <title>Comments on &b09;</title>
 <para>
 &b09; is an enhanced structured Basic language programming
-system specially created for the 6809 Advanced Microprocessor
-used by the Dragon Computer.
+system specially created for the &CPU; Advanced Microprocessor
+used by the &make;.
 In addition to the standard BASIC language statements and functions,
 &b09; includes many of the useful elements of the PASCAL
 programming language so that programs can be modular,
@@ -107,7 +114,7 @@
 
 <listitem>
 <para>
-Graphics Interface Module for Access to Dragon Computer Color
+Graphics Interface Module for Access to &make; Color
 Graphics Functions
 </para>
 </listitem>
@@ -144,10 +151,10 @@
 <title>The History of &b09;</title>
 <para>
 &b09; was conceived in 1978 as a high-performance
-programming language to demonstrate the capabilities of the 6809
+programming language to demonstrate the capabilities of the &CPU;
 microprocessor to efficiently run high-level languages. &b09;
-was developed at the same time as the 6809 under the auspices of the
-architects of the 6809. The project covered
+was developed at the same time as the &CPU; under the auspices of the
+architects of the &CPU;. The project covered
 almost two years, and incorporated the results of research in such areas as
 interactive compilation, fast floating point arithmetic algorithms, storage
 management, high-level symbolic debugging, and structured language
@@ -3833,7 +3840,7 @@
  calls a procedure by name; when that procedure ends, control will pass
 to the next statement after the RUN. It is most often used to call a
 procedure inside the workspace, but it can also be used to call a previously
-compiled (by the PACK command) procedure or a 6809 machine language
+compiled (by the PACK command) procedure or a &CPU; machine language
 procedure outside the
 workspace. The name can be optionally taken from a string variable.
 </para></sect2>
@@ -3869,9 +3876,9 @@
 found there, &b09; will try to find a disk file having the same name in the
 current execution directory, load it, and run it.
 In either case, &b09; checks to see if the called procedure is a &b09;
-I-code module or a 6809 machine language module, and executes it
-accordingly. If it is a 6809 machine language module, &b09; executes a
-JSR instruction to its entry point and the module is executed as 6809
+I-code module or a &CPU; machine language module, and executes it
+accordingly. If it is a &CPU; machine language module, &b09; executes a
+JSR instruction to its entry point and the module is executed as &CPU;
 native code. The machine language routine can return to the original
 calling procedure by executing an RTS instruction. The diagram on the
 next page shows what the stack frame passed to machine-language
@@ -3905,7 +3912,7 @@
 |                      |         |
 |  return address      |      2 bytes
 |                      |         |
-+----------------------+        ---  &lt;- 6809 Stack Pointer
++----------------------+        ---  &lt;- &CPU; Stack Pointer
                                         Register value
 </literallayout>
 </figure>
@@ -5763,7 +5770,7 @@
 during execution.  &b09; I-code instructions that reference variable
 storage, statements, labels, etc., contain the actual memory addresses
 so no table searching is ever required.  Off course, &b09; fully exploits
-the power of the 6809's instruction set which was optimized for efficient
+the power of the &CPU;'s instruction set which was optimized for efficient
 execution of compiler-produced code.
 </para>
 <para>
@@ -5803,7 +5810,7 @@
 </para>
 <para>
 Nonetheless, INTEGER operations are faster because they generally have
-corresponding 6809 machine-language instructions. Overall program speed
+corresponding &CPU; machine-language instructions. Overall program speed
 will increase and storage requirements will decrease if INTEGERs are used
 whenever possible. INTEGER arithmetic operations use the same symbols as
 REAL but &b09; automatically selects the INTEGER operations when working
@@ -5966,7 +5973,7 @@
 &b09; also eliminates any possible excuse for not using good
 structured programming style that produces
 efficient, reliable, readable, and maintainable software. &b09; generates
-optimized code to be executed by the 6809 which is the most
+optimized code to be executed by the &CPU; which is the most
 powerful 8-bit processor in existence at the time of this writing.
 But a computer can only execute what
 it is told to execute, and no language implementation can make up for an
@@ -7321,398 +7328,6 @@
 </appendix>
 
 
-<appendix>
-<title>The &b09; Graphics Interface Module</title>
-<para>
-The Graphics Interface module provides a simple and convenient
-way to access the color graphics and joystick functions of the
-Dragon Computer from &b09; programs. The module is a program
-written in assembly language and stored in a file called "GFX". It
-can be loaded into memory using the OS-9 "LOAD" command prior to or
-after called &b09;, or it will be automatically called by &b09;
-the first time it is referenced in a program if the "GFX" file is
-located in the execution ("CMDS") directory.
-</para>
-<para>
-"GFX" is called using the &b09; "RUN" statement. The first
-parameter passed is the name of the graphics function desired.
-Other parameters are used to pass coordinates, color modes, etc.
-</para>
-<para>
-The are two basic graphics modes: 4-color having 128 by 192
-pixel resolution, and 2-color having 256 by 192 pixel resolution.
-The display is treated as a 256 by 192 point grid with coordinates
-0,0 in the lower left-hand corner. X (horizontal) coordinates in
-either mode must be in the range of 0 to 255. An X-coordinate
-greater than 255 will cause a run-time error. Y coordinates
-(vertical) must be in the range of 0 to 191. A number greater than
-191 will be replaced by 191. Some of the graphics functions require
-or optionally accept a color mode which controls the foreground
-color and color set. The mode and color codes are given in the
-table on the next page.
-</para>
-<beginpage/>
-<table frame="none">
- <title>Color Graphics Modes and Color Codes</title>
-<tgroup cols="6">
-<colspec colname="c1" colwidth="0.6in"/>
-<colspec colname="c2" colwidth="0.4in"/>
-<colspec colname="c3" colwidth="1in"/>
-<colspec colname="c4" colwidth="1in"/>
-<colspec colname="c5" colwidth="1in"/>
-<colspec colname="c6" colwidth="1in"/>
-<thead>
-<row>
-<entry morerows="1" namest="c2">Color Code</entry>
-<entry align="center" namest="c3" nameend="c4">Two Color Format</entry>
-<entry align="center" namest="c5" nameend="c6">Four Color Format</entry>
-</row>
-<row>
-<entry namest="c3">Background</entry>
-<entry namest="c4">Foreground</entry>
-<entry namest="c5">Background</entry>
-<entry namest="c6">Foreground</entry>
-</row>
-</thead>
-<tbody>
-<row>
-<entry morerows="3" valign="middle">Color Set 1</entry>
-<entry align="center">00</entry>
-<entry align="left">Black</entry>
-<entry align="left">Black</entry>
-<entry align="left">Green</entry>
-<entry align="left">Green</entry>
-</row>
-<row>
-<entry align="center">01</entry>
-<entry align="left">Black</entry>
-<entry align="left">Green</entry>
-<entry align="left">Green</entry>
-<entry align="left">Yellow</entry>
-</row>
-<row>
-<entry align="center">02</entry>
-<entry namest="c5" align="left">Green</entry>
-<entry align="left">Blue</entry>
-</row>
-<row rowsep="1">
-<entry align="center">03</entry>
-<entry namest="c5" align="left">Green</entry>
-<entry align="left">Red</entry>
-</row>
-<row>
-<entry morerows="3" valign="middle">Color Set 2</entry>
-<entry align="center">04</entry>
-<entry align="left">Black</entry>
-<entry align="left">Black</entry>
-<entry align="left">Buff</entry>
-<entry align="left">Buff</entry>
-</row>
-<row>
-<entry align="center" namest="c2">05</entry>
-<entry align="left">Black</entry>
-<entry align="left">Buff</entry>
-<entry align="left">Buff</entry>
-<entry align="left">Cyan</entry>
-</row>
-<row>
-<entry align="center" namest="c2">06</entry>
-<entry namest="c5" align="left">Buff</entry>
-<entry align="left">Magenta</entry>
-</row>
-<row rowsep="1">
-<entry align="center" namest="c2">07</entry>
-<entry namest="c5" align="left">Buff</entry>
-<entry align="left">Orange</entry>
-</row>
-<row>
-<entry morerows="3" valign="middle">Color Set 3*</entry>
-<entry align="center">08</entry>
-<entry namest="c5" align="left">Black</entry>
-<entry align="left">Black</entry>
-</row>
-<row>
-<entry align="center" namest="c2">09</entry>
-<entry namest="c5" align="left">Black</entry>
-<entry align="left">Dark Green</entry>
-</row>
-<row>
-<entry align="center" namest="c2">10</entry>
-<entry namest="c5" align="left">Black</entry>
-<entry align="left">Med. Green</entry>
-</row>
-<row rowsep="1">
-<entry align="center" namest="c2">11</entry>
-<entry namest="c5" align="left">Black</entry>
-<entry align="left">Light Green</entry>
-</row>
-<row>
-<entry morerows="3" valign="middle">Color Set 4*</entry>
-<entry align="center">12</entry>
-<entry namest="c5" align="left">Black</entry>
-<entry align="left">Black</entry>
-</row>
-<row>
-<entry align="center" namest="c2">13</entry>
-<entry namest="c5" align="left">Black</entry>
-<entry align="left">Green</entry>
-</row>
-<row>
-<entry align="center" namest="c2">14</entry>
-<entry namest="c5" align="left">Black</entry>
-<entry align="left">Red</entry>
-</row>
-<row>
-<entry align="center" namest="c2">15</entry>
-<entry namest="c5" align="left">Black</entry>
-<entry align="left">Buff</entry>
-</row>
-</tbody>
-</tgroup>
-</table>
-<note>
-<para>
-Color Sets 3 and 4 are not available on PAL video system
-(U.K. and European) models.
-</para>
-</note>
-<bridgehead renderas="sect2">MODE</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Mode",<replaceable>format,color</replaceable>)</command>
-</cmdsynopsis>
-<para>
-MODE switches the screen from alphanumeric to graphics display mode,
-and selects the screen mode and color mode. "Format" determines
-between two-color (Format = 0), or four-color (Format = 1)
-graphics modes. "Color" is the initial color code that specifies
-the foreground color and color set.
-</para>
-<para>
-This command must be given before aby other graphics command is
-used. The first time MODE is called, it requests 6K bytres of memory
-from OS-9 for use as the graphics display memory. MODE will return
-an error if sufficient free memory is not available.
-</para>
-<para>
-An example:
-<programlisting>
-RUN GFX("Mode",1,3)
-</programlisting>
-selects four-color mode graphics is used, and the initial
-foreground color is red.
-</para>
-<bridgehead renderas="sect2">MOVE</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Move",<replaceable>x,y</replaceable>)</command>
-</cmdsynopsis>
-<para>
-MOVE positions the (invisible) graphics cursor to the specified
-location without changing the display. X and Y are the coordinates
-of the new position.
-</para>
-<para>
-Example:
-<programlisting>
-RUN GFX("Move",0,0)
-</programlisting>
-This example positions the cursor in the lower left-hand corner.
-</para>
-<bridgehead renderas="sect2">COLOR</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Color",<replaceable>color</replaceable>)</command>
-</cmdsynopsis>
-<para>
-COLOR changes the current foreground color (and possibly the color
-set). The current graphics mode and cursor position are not
-changed. For example:
-<programlisting>
-RUN GFX("Color",0)
-</programlisting>
-changes the foreground color to green in four-color format (or
-black in two-color format).
-</para>
-<bridgehead renderas="sect2">POINT</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Point",<replaceable>x,y</replaceable>) or</command><sbr/>
-<command>RUN GFX("Point",<replaceable>x,y,color</replaceable>)</command>
-</cmdsynopsis>
-<para>
-POINT moves the graphics cursor to the specified X.Y coordinate and
-sets the pixel at that coordinate to the current foreground color.
-If the optional "Color" is specified, the current foreground color
-is set to the given "Color". For example:
-<programlisting>
-RUN GFX("Point",0,192,1)
-</programlisting>
-Point moves the cursor to the upper left-hand corner and changes
-the foreground color to green in two-color format, or it changes
-the color to yellow in the four-color format.
-</para>
-<bridgehead renderas="sect2">CLEAR</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Clear") or</command><sbr/>
-<command>RUN GFX("Clear",<replaceable>color</replaceable>)</command>
-</cmdsynopsis>
-<para>
-CLEAR resets all points on the screen to the background color, or
-if the optional color is given presets the screen to that color.
-The current graphics cursor is reset to (0,0).
-</para>
-<bridgehead renderas="sect2">LINE</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Line",<replaceable>x2,y2</replaceable>)</command><sbr/>
-<command>RUN GFX("Line",<replaceable>x2,y2,color</replaceable>)</command><sbr/>
-<command>RUN GFX("Line",<replaceable>x1,y1,x2,y2</replaceable>)</command><sbr/>
-<command>RUN GFX("Line",<replaceable>x1,y1,x2,y2,color</replaceable>)</command>
-</cmdsynopsis>
-<para>
-LINE draw lines in various ways. If one coordinate is given, the
-line will be drawn from the current graphics cursor position to the
-coordinates specified. If two sets of coordinates are given, they
-are used as the start and end points of the line. The line will be
-drawn in the current foreground color unless a new color is given
-as a parameter. After the line is drawn the graphics cursor will be
-positioned at x2,y2. For example
-<programlisting>
-RUN GFX("Line",0,0,0,192)
-</programlisting>
-draws a line from (0,0) to (0,192).
-<programlisting>
-RUN GFX("line",24,65,2)
-</programlisting>
-draws a blue line (4-color mode) to point 24,65.
-</para>
-<bridgehead renderas="sect2">CIRCLE</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Circle",<replaceable>radius</replaceable>)</command><sbr/>
-<command>RUN GFX("Circle",<replaceable>radius,color</replaceable>)</command><sbr/>
-<command>RUN GFX("Circle",<replaceable>x,y,radius</replaceable>)</command><sbr/>
-<command>RUN GFX("Circle",<replaceable>x,y,radius,color</replaceable>)</command>
-</cmdsynopsis>
-<para>
-CIRCLE draws a circle of the given radius. The current graphics
-cursor position is assumed if no X,Y value is given. The current
-foreground color is assumed if the Color parameter is not used.
-The center of the circle must be on the screen.
-</para>
-<bridgehead renderas="sect2">ALPHA</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Alpha")</command>
-</cmdsynopsis>
-<para>
-Alpha is a quick convenient way of getting the screen back to
-alphanumeric mode. When graphics mode is entered again, the screen
-will show the previous unchanged graphics display.
-</para>
-<bridgehead renderas="sect2">QUIT</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Quit")</command>
-</cmdsynopsis>
-<para>
-QUIT switches the screen back to alpha mode and returns the 6K byte
-graphics display memory to OS-9.
-</para>
-<bridgehead renderas="sect2">GLOC</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Gloc",<replaceable>vdisp</replaceable>)</command>
-</cmdsynopsis>
-<para>
-GLOC returns the address of the video display RAM as an integer number.
-This address may be used in subsequent PEEK and POKE
-operations to access the video display directly. GLOC can be used
-to create special functions that are not available in the Graphics
-Module.
-</para>
-<bridgehead renderas="sect2">GCOLR</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Gcolr",<replaceable>color</replaceable>)</command><sbr/>
-<command>RUN GFX("Gcolr",<replaceable>x,y,color</replaceable>)</command>
-</cmdsynopsis>
-<para>
-GCOLR is used to read the color of the pixel at the current
-graphics cursor position, or from the coordinates X,Y. The
-parameter "Color" may be an integer or a byte variable in which the
-color code is returned.
-</para>
-<bridgehead renderas="sect2">JOYSTK</bridgehead>
-<cmdsynopsis>
-<command>RUN GFX("Joystk",<replaceable>stick,fire,x,y</replaceable>)</command>
-</cmdsynopsis>
-<para>
-JOYSTK returns the status of the specified joystick's Fire button,
-and returns the X,Y position of the joystick. The Fire button may
-be read as a BYTE, INTEGER, or a BOOLEAN value. Non-zero (TRUE)
-means the button was pressed. The X,Y values returned may be BYTE
-or INTEGER variables, and they will be in the range 0 to 63. The
-Stick parameter may be BYTE or INTEGER, and should be 0 for
-RIGHT, or 1 for LEFT, depending on whether the RIGHT or the LEFT
-joystick is to be tested.
-</para>
-<para>
-Example:
-<programlisting>
-RUN GRX("Joystk",1,leftfire,leftx,lefty)
-</programlisting>
-</para>
-<bridgehead renderas="sect1">A Sample Graphics Program</bridgehead>
-<para>
-The program on the next page illustrates how the GFX module is
-called and used. It creates an analog clock on the graphics
-display.
-</para>
-<para>
-<programlisting>
-PROCEDURE clk
- 0000      (* Simple Clock Simulator *)
- 001C      DIM time(4),last(4),xx(3),yy(3):INTEGER
- 0043      DIM x0,y0,radius,bkg:INTEGER
- 0056      DIM i,j,x1,y1,x2,y2:INTEGER
- 0071      DEG
- 0073      bkg=0
- 007A      x0=128
- 0081      y0=96
- 0088      radius=95
- 008F      RUN GFX("MODE",1,bkg+1)
- 00A5      RUN GFX("CLEAR")
- 00B2      RUN GFX("CIRCLE",x0,y0,radius)
- 00CF      FOR i=0 to 89 STEP 6
- 00E4        x2=SIN(i)*radius
- 00F4        y2=COS(i)*radius
- 0104        x1=x2*.9
- 0115        y1=y2*.9
- 0126        j=MOD(i/30,3)+bkg+1
- 013B        RUN GFX("LINE",x0+x1,y0+y1,x0+x2,y0+y2,j)
- 016C        RUN GFX("LINE",x0-x1,y0-y1,x0-x2,y0-y2,j)
- 019D        RUN GFX("LINE",x0+y1,y0-x1,x0+y2,y0-x2,j)
- 01CE        RUN GFX("LINE",x0-y1,y0+x1,x0-y2,y0+x2,j)
- 01FF      NEXT i
- 020A      FOR i=1 TO 3
- 021A        time(i)=0
- 0225        xx(i)=x0
- 0231        yy(i)=y0
- 023D      NEXT i
- 0248      LOOP
- 024A        time$=DATE$
- 0250        last=time
- 0258        time(3)=VAL(MID$(time$,16,2))*6
- 026E        time(2)=VAL(MID$(time$(13,2))*6
- 0284        time(1)=MOD(VAL(MID$(time$,10,2))*30+time/2)/12,360)
- 02A9        j=last(3)
- 02B3        FOR i=3 TO 1 STEP -1
- 02C9          IF i=3 OR j=0 OR ABS(time(i)-last(i+1))&lt;6 OR
-               ABS(time(i)-j)&lt;6 THEN
- 0300            RUN GFX("LINE",x0,y0,xx(i),yy(i),bkg)
- 032B            xx(i)=x0+SIN(time(i))*radius*(.3+i*.2)
- 035A            yy(i)=y0+COS(time(i))*radius*(.3+i*.2)
- 0389            RUN GFX("LINE",x0,y0,xx(i),yy(i),bkg+i)
- 03B7          ENDIF
- 03B9        NEXT i
- 03C4        WHILE time$=DATE$ DO
- 03CF        ENDWHILE
- 03D3      ENDLOOP
-</programlisting>
-</para>
-
-</appendix>
+&gfxapp;
 &gfx2app;
 </book>
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/docs/basic09/gfx.appendix	Tue Mar 04 20:07:34 2003 +0000
@@ -0,0 +1,393 @@
+<appendix>
+<title>The &b09; Graphics Interface Module</title>
+<para>
+The Graphics Interface module provides a simple and convenient
+way to access the color graphics and joystick functions of the
+Dragon Computer from &b09; programs. The module is a program
+written in assembly language and stored in a file called "GFX". It
+can be loaded into memory using the OS-9 "LOAD" command prior to or
+after called &b09;, or it will be automatically called by &b09;
+the first time it is referenced in a program if the "GFX" file is
+located in the execution ("CMDS") directory.
+</para>
+<para>
+"GFX" is called using the &b09; "RUN" statement. The first
+parameter passed is the name of the graphics function desired.
+Other parameters are used to pass coordinates, color modes, etc.
+</para>
+<para>
+The are two basic graphics modes: 4-color having 128 by 192
+pixel resolution, and 2-color having 256 by 192 pixel resolution.
+The display is treated as a 256 by 192 point grid with coordinates
+0,0 in the lower left-hand corner. X (horizontal) coordinates in
+either mode must be in the range of 0 to 255. An X-coordinate
+greater than 255 will cause a run-time error. Y coordinates
+(vertical) must be in the range of 0 to 191. A number greater than
+191 will be replaced by 191. Some of the graphics functions require
+or optionally accept a color mode which controls the foreground
+color and color set. The mode and color codes are given in the
+table on the next page.
+</para>
+<beginpage/>
+<table frame="none">
+ <title>Color Graphics Modes and Color Codes</title>
+<tgroup cols="6">
+<colspec colname="c1" colwidth="0.6in"/>
+<colspec colname="c2" colwidth="0.4in"/>
+<colspec colname="c3" colwidth="1in"/>
+<colspec colname="c4" colwidth="1in"/>
+<colspec colname="c5" colwidth="1in"/>
+<colspec colname="c6" colwidth="1in"/>
+<thead>
+<row>
+<entry morerows="1" namest="c2">Color Code</entry>
+<entry align="center" namest="c3" nameend="c4">Two Color Format</entry>
+<entry align="center" namest="c5" nameend="c6">Four Color Format</entry>
+</row>
+<row>
+<entry namest="c3">Background</entry>
+<entry namest="c4">Foreground</entry>
+<entry namest="c5">Background</entry>
+<entry namest="c6">Foreground</entry>
+</row>
+</thead>
+<tbody>
+<row>
+<entry morerows="3" valign="middle">Color Set 1</entry>
+<entry align="center">00</entry>
+<entry align="left">Black</entry>
+<entry align="left">Black</entry>
+<entry align="left">Green</entry>
+<entry align="left">Green</entry>
+</row>
+<row>
+<entry align="center">01</entry>
+<entry align="left">Black</entry>
+<entry align="left">Green</entry>
+<entry align="left">Green</entry>
+<entry align="left">Yellow</entry>
+</row>
+<row>
+<entry align="center">02</entry>
+<entry namest="c5" align="left">Green</entry>
+<entry align="left">Blue</entry>
+</row>
+<row rowsep="1">
+<entry align="center">03</entry>
+<entry namest="c5" align="left">Green</entry>
+<entry align="left">Red</entry>
+</row>
+<row>
+<entry morerows="3" valign="middle">Color Set 2</entry>
+<entry align="center">04</entry>
+<entry align="left">Black</entry>
+<entry align="left">Black</entry>
+<entry align="left">Buff</entry>
+<entry align="left">Buff</entry>
+</row>
+<row>
+<entry align="center" namest="c2">05</entry>
+<entry align="left">Black</entry>
+<entry align="left">Buff</entry>
+<entry align="left">Buff</entry>
+<entry align="left">Cyan</entry>
+</row>
+<row>
+<entry align="center" namest="c2">06</entry>
+<entry namest="c5" align="left">Buff</entry>
+<entry align="left">Magenta</entry>
+</row>
+<row rowsep="1">
+<entry align="center" namest="c2">07</entry>
+<entry namest="c5" align="left">Buff</entry>
+<entry align="left">Orange</entry>
+</row>
+<row>
+<entry morerows="3" valign="middle">Color Set 3*</entry>
+<entry align="center">08</entry>
+<entry namest="c5" align="left">Black</entry>
+<entry align="left">Black</entry>
+</row>
+<row>
+<entry align="center" namest="c2">09</entry>
+<entry namest="c5" align="left">Black</entry>
+<entry align="left">Dark Green</entry>
+</row>
+<row>
+<entry align="center" namest="c2">10</entry>
+<entry namest="c5" align="left">Black</entry>
+<entry align="left">Med. Green</entry>
+</row>
+<row rowsep="1">
+<entry align="center" namest="c2">11</entry>
+<entry namest="c5" align="left">Black</entry>
+<entry align="left">Light Green</entry>
+</row>
+<row>
+<entry morerows="3" valign="middle">Color Set 4*</entry>
+<entry align="center">12</entry>
+<entry namest="c5" align="left">Black</entry>
+<entry align="left">Black</entry>
+</row>
+<row>
+<entry align="center" namest="c2">13</entry>
+<entry namest="c5" align="left">Black</entry>
+<entry align="left">Green</entry>
+</row>
+<row>
+<entry align="center" namest="c2">14</entry>
+<entry namest="c5" align="left">Black</entry>
+<entry align="left">Red</entry>
+</row>
+<row>
+<entry align="center" namest="c2">15</entry>
+<entry namest="c5" align="left">Black</entry>
+<entry align="left">Buff</entry>
+</row>
+</tbody>
+</tgroup>
+</table>
+<note>
+<para>
+Color Sets 3 and 4 are not available on PAL video system
+(U.K. and European) models.
+</para>
+</note>
+<bridgehead renderas="sect2">MODE</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Mode",<replaceable>format,color</replaceable>)</command>
+</cmdsynopsis>
+<para>
+MODE switches the screen from alphanumeric to graphics display mode,
+and selects the screen mode and color mode. "Format" determines
+between two-color (Format = 0), or four-color (Format = 1)
+graphics modes. "Color" is the initial color code that specifies
+the foreground color and color set.
+</para>
+<para>
+This command must be given before aby other graphics command is
+used. The first time MODE is called, it requests 6K bytres of memory
+from OS-9 for use as the graphics display memory. MODE will return
+an error if sufficient free memory is not available.
+</para>
+<para>
+An example:
+<programlisting>
+RUN GFX("Mode",1,3)
+</programlisting>
+selects four-color mode graphics is used, and the initial
+foreground color is red.
+</para>
+<bridgehead renderas="sect2">MOVE</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Move",<replaceable>x,y</replaceable>)</command>
+</cmdsynopsis>
+<para>
+MOVE positions the (invisible) graphics cursor to the specified
+location without changing the display. X and Y are the coordinates
+of the new position.
+</para>
+<para>
+Example:
+<programlisting>
+RUN GFX("Move",0,0)
+</programlisting>
+This example positions the cursor in the lower left-hand corner.
+</para>
+<bridgehead renderas="sect2">COLOR</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Color",<replaceable>color</replaceable>)</command>
+</cmdsynopsis>
+<para>
+COLOR changes the current foreground color (and possibly the color
+set). The current graphics mode and cursor position are not
+changed. For example:
+<programlisting>
+RUN GFX("Color",0)
+</programlisting>
+changes the foreground color to green in four-color format (or
+black in two-color format).
+</para>
+<bridgehead renderas="sect2">POINT</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Point",<replaceable>x,y</replaceable>) or</command><sbr/>
+<command>RUN GFX("Point",<replaceable>x,y,color</replaceable>)</command>
+</cmdsynopsis>
+<para>
+POINT moves the graphics cursor to the specified X.Y coordinate and
+sets the pixel at that coordinate to the current foreground color.
+If the optional "Color" is specified, the current foreground color
+is set to the given "Color". For example:
+<programlisting>
+RUN GFX("Point",0,192,1)
+</programlisting>
+Point moves the cursor to the upper left-hand corner and changes
+the foreground color to green in two-color format, or it changes
+the color to yellow in the four-color format.
+</para>
+<bridgehead renderas="sect2">CLEAR</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Clear") or</command><sbr/>
+<command>RUN GFX("Clear",<replaceable>color</replaceable>)</command>
+</cmdsynopsis>
+<para>
+CLEAR resets all points on the screen to the background color, or
+if the optional color is given presets the screen to that color.
+The current graphics cursor is reset to (0,0).
+</para>
+<bridgehead renderas="sect2">LINE</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Line",<replaceable>x2,y2</replaceable>)</command><sbr/>
+<command>RUN GFX("Line",<replaceable>x2,y2,color</replaceable>)</command><sbr/>
+<command>RUN GFX("Line",<replaceable>x1,y1,x2,y2</replaceable>)</command><sbr/>
+<command>RUN GFX("Line",<replaceable>x1,y1,x2,y2,color</replaceable>)</command>
+</cmdsynopsis>
+<para>
+LINE draw lines in various ways. If one coordinate is given, the
+line will be drawn from the current graphics cursor position to the
+coordinates specified. If two sets of coordinates are given, they
+are used as the start and end points of the line. The line will be
+drawn in the current foreground color unless a new color is given
+as a parameter. After the line is drawn the graphics cursor will be
+positioned at x2,y2. For example
+<programlisting>
+RUN GFX("Line",0,0,0,192)
+</programlisting>
+draws a line from (0,0) to (0,192).
+<programlisting>
+RUN GFX("line",24,65,2)
+</programlisting>
+draws a blue line (4-color mode) to point 24,65.
+</para>
+<bridgehead renderas="sect2">CIRCLE</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Circle",<replaceable>radius</replaceable>)</command><sbr/>
+<command>RUN GFX("Circle",<replaceable>radius,color</replaceable>)</command><sbr/>
+<command>RUN GFX("Circle",<replaceable>x,y,radius</replaceable>)</command><sbr/>
+<command>RUN GFX("Circle",<replaceable>x,y,radius,color</replaceable>)</command>
+</cmdsynopsis>
+<para>
+CIRCLE draws a circle of the given radius. The current graphics
+cursor position is assumed if no X,Y value is given. The current
+foreground color is assumed if the Color parameter is not used.
+The center of the circle must be on the screen.
+</para>
+<bridgehead renderas="sect2">ALPHA</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Alpha")</command>
+</cmdsynopsis>
+<para>
+Alpha is a quick convenient way of getting the screen back to
+alphanumeric mode. When graphics mode is entered again, the screen
+will show the previous unchanged graphics display.
+</para>
+<bridgehead renderas="sect2">QUIT</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Quit")</command>
+</cmdsynopsis>
+<para>
+QUIT switches the screen back to alpha mode and returns the 6K byte
+graphics display memory to OS-9.
+</para>
+<bridgehead renderas="sect2">GLOC</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Gloc",<replaceable>vdisp</replaceable>)</command>
+</cmdsynopsis>
+<para>
+GLOC returns the address of the video display RAM as an integer number.
+This address may be used in subsequent PEEK and POKE
+operations to access the video display directly. GLOC can be used
+to create special functions that are not available in the Graphics
+Module.
+</para>
+<bridgehead renderas="sect2">GCOLR</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Gcolr",<replaceable>color</replaceable>)</command><sbr/>
+<command>RUN GFX("Gcolr",<replaceable>x,y,color</replaceable>)</command>
+</cmdsynopsis>
+<para>
+GCOLR is used to read the color of the pixel at the current
+graphics cursor position, or from the coordinates X,Y. The
+parameter "Color" may be an integer or a byte variable in which the
+color code is returned.
+</para>
+<bridgehead renderas="sect2">JOYSTK</bridgehead>
+<cmdsynopsis>
+<command>RUN GFX("Joystk",<replaceable>stick,fire,x,y</replaceable>)</command>
+</cmdsynopsis>
+<para>
+JOYSTK returns the status of the specified joystick's Fire button,
+and returns the X,Y position of the joystick. The Fire button may
+be read as a BYTE, INTEGER, or a BOOLEAN value. Non-zero (TRUE)
+means the button was pressed. The X,Y values returned may be BYTE
+or INTEGER variables, and they will be in the range 0 to 63. The
+Stick parameter may be BYTE or INTEGER, and should be 0 for
+RIGHT, or 1 for LEFT, depending on whether the RIGHT or the LEFT
+joystick is to be tested.
+</para>
+<para>
+Example:
+<programlisting>
+RUN GRX("Joystk",1,leftfire,leftx,lefty)
+</programlisting>
+</para>
+<bridgehead renderas="sect1">A Sample Graphics Program</bridgehead>
+<para>
+The program on the next page illustrates how the GFX module is
+called and used. It creates an analog clock on the graphics
+display.
+</para>
+<para>
+<programlisting>
+PROCEDURE clk
+ 0000      (* Simple Clock Simulator *)
+ 001C      DIM time(4),last(4),xx(3),yy(3):INTEGER
+ 0043      DIM x0,y0,radius,bkg:INTEGER
+ 0056      DIM i,j,x1,y1,x2,y2:INTEGER
+ 0071      DEG
+ 0073      bkg=0
+ 007A      x0=128
+ 0081      y0=96
+ 0088      radius=95
+ 008F      RUN GFX("MODE",1,bkg+1)
+ 00A5      RUN GFX("CLEAR")
+ 00B2      RUN GFX("CIRCLE",x0,y0,radius)
+ 00CF      FOR i=0 to 89 STEP 6
+ 00E4        x2=SIN(i)*radius
+ 00F4        y2=COS(i)*radius
+ 0104        x1=x2*.9
+ 0115        y1=y2*.9
+ 0126        j=MOD(i/30,3)+bkg+1
+ 013B        RUN GFX("LINE",x0+x1,y0+y1,x0+x2,y0+y2,j)
+ 016C        RUN GFX("LINE",x0-x1,y0-y1,x0-x2,y0-y2,j)
+ 019D        RUN GFX("LINE",x0+y1,y0-x1,x0+y2,y0-x2,j)
+ 01CE        RUN GFX("LINE",x0-y1,y0+x1,x0-y2,y0+x2,j)
+ 01FF      NEXT i
+ 020A      FOR i=1 TO 3
+ 021A        time(i)=0
+ 0225        xx(i)=x0
+ 0231        yy(i)=y0
+ 023D      NEXT i
+ 0248      LOOP
+ 024A        time$=DATE$
+ 0250        last=time
+ 0258        time(3)=VAL(MID$(time$,16,2))*6
+ 026E        time(2)=VAL(MID$(time$(13,2))*6
+ 0284        time(1)=MOD(VAL(MID$(time$,10,2))*30+time/2)/12,360)
+ 02A9        j=last(3)
+ 02B3        FOR i=3 TO 1 STEP -1
+ 02C9          IF i=3 OR j=0 OR ABS(time(i)-last(i+1))&lt;6 OR
+               ABS(time(i)-j)&lt;6 THEN
+ 0300            RUN GFX("LINE",x0,y0,xx(i),yy(i),bkg)
+ 032B            xx(i)=x0+SIN(time(i))*radius*(.3+i*.2)
+ 035A            yy(i)=y0+COS(time(i))*radius*(.3+i*.2)
+ 0389            RUN GFX("LINE",x0,y0,xx(i),yy(i),bkg+i)
+ 03B7          ENDIF
+ 03B9        NEXT i
+ 03C4        WHILE time$=DATE$ DO
+ 03CF        ENDWHILE
+ 03D3      ENDLOOP
+</programlisting>
+</para>
+
+</appendix>