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comparison docs/nitros9guide/display.appendix @ 1011:cc153d1671f7

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Updated for new manuals
author boisy
date Tue, 04 Mar 2003 15:11:34 +0000
parents f9c66ad345d1
children d9ed9d44b70c
comparison
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1010:1027549ee381 1011:cc153d1671f7
1 <appendix> 1 <appendix>
2 <title>Display System Functions</title> 2 <title>VDG Display System Functions</title>
3 3
4 <section> 4 <section>
5 <title>The Video Display</title> 5 <title>The Video Display Generator</title>
6 <para> 6 <para>
7 &vendor; OS-9 allows the video display to be used in 7 &os9level allows the VDG display to be used in
8 alphanumeric, semigraphic, and graphics modes. There are many 8 alphanumeric, semigraphic, and graphics modes. There are many
9 built-in functions to control the display, which are activated by 9 built-in functions to control the display, which are activated by
10 used of various ASCII control character. Thus, these functions are 10 used of various ASCII control character. Thus, these functions are
11 available for use by software written in any language using standard 11 available for use by software written in any language using standard
12 output statements (such as &quot;PRINT&quot; in BASIC). The &make; 12 output statements (such as &quot;PRINT&quot; in BASIC). The &make;'s Basic09
13 Computer's Basic09
14 language has a Graphics Interface Module that can automatically 13 language has a Graphics Interface Module that can automatically
15 generate these codes using Basic09 RUN statements. 14 generate these codes using Basic09 RUN statements.
16 </para> 15 </para>
17 <para> 16 <para>
18 The display system has two display modes: Alphanumeric 17 The display system has two display modes: Alphanumeric
19 (&quot;Alpha&quot;) mode and Graphics mode. The Alphanumeric mode also 18 (&quot;Alpha&quot;) mode and Graphics mode. The Alphanumeric mode also
20 includes &quot;semigraphic&quot; box-graphics. The &make; Computer's display 19 includes &quot;semigraphic&quot; box-graphics. The &make;'s display
21 system uses a separate - memory area for each display mode so 20 system uses a separate - memory area for each display mode so
22 operations on the Alpha display do not affect the Graphics display, 21 operations on the Alpha display do not affect the Graphics display,
23 and visa-versa. Either display can be selected under software 22 and visa-versa. Either display can be selected under software
24 control. 23 control.
25 </para> 24 </para>
84 <para> 83 <para>
85 Each 8-bit character is assumed to be an ASCII character and is 84 Each 8-bit character is assumed to be an ASCII character and is
86 displayed if its high order bit (sign bit) is cleared. Lower case 85 displayed if its high order bit (sign bit) is cleared. Lower case
87 letters are displayed in reverse video. If the high order bit of 86 letters are displayed in reverse video. If the high order bit of
88 the character is set it is assumed to be a &quot;Semigraphic 6&quot; graphics 87 the character is set it is assumed to be a &quot;Semigraphic 6&quot; graphics
89 box. See the &make; Computer manual for an explanation of semigraphics 88 box. See the &make; manual for an explanation of semigraphics
90 functions. 89 functions.
91 </para> 90 </para>
92 91
93 <table frame="none"> 92 <table frame="none">
94 <title>Alpha Mode Command Codes</title> 93 <title>Alpha Mode Command Codes</title>
440 439
441 </section> 440 </section>
442 <section> 441 <section>
443 <title>Get Status Commands</title> 442 <title>Get Status Commands</title>
444 <para> 443 <para>
445 The &make; Computer I/O driver includes OS-9 Get Status 444 The &make; I/O driver includes OS-9 Get Status
446 commands that return the display status and joystick values, 445 commands that return the display status and joystick values,
447 respectively. These are accessable via the Basic09 Graphics 446 respectively. These are accessable via the Basic09 Graphics
448 Interface Module, or by the assembly language system calls listed 447 Interface Module, or by the assembly language system calls listed
449 below: 448 below:
450 </para> 449 </para>