Detecting Colour and Monochrome Monitors: Difference between revisions
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Detecting |
Detecting whether a user has a colour or monochrome video card is a trivial task. The [[BIOS]] [[Memory Map (x86)#BIOS Data Area .28BDA.29|data segment]] has a value in it for this information. Below is a function (in ISO C) to retrieve this: |
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== The Function == |
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Here is some C source example of how I do it. |
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<syntaxhighlight lang="c"> |
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#include <stdint.h> |
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enum video_type |
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<pre> |
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/* video card mono/colour detection by Dark Fiber |
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* returns 0=mono, 1=colour |
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*/ |
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int detect_video_type(void) |
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{ |
{ |
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VIDEO_TYPE_NONE = 0x00, |
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int rc; |
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VIDEO_TYPE_COLOUR = 0x20, |
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char c=(*(volatile USHORT*)0x410)&0x30; |
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VIDEO_TYPE_MONOCHROME = 0x30, |
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}; |
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uint16_t detect_bios_area_hardware(void) |
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/* C can be 0x00 or 0x20 for colour, 0x30 for mono |
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{ |
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if(c==0x30){ |
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const uint16_t* bda_detected_hardware_ptr = (const uint16_t*) 0x410; |
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rc=0; // mono |
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return *bda_detected_hardware_ptr; |
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} |
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} |
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else |
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{ |
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enum video_type get_bios_area_video_type(void) |
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rc=1; // colour |
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{ |
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} |
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return (enum video_type) (detect_bios_area_hardware() & 0x30); |
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return rc; |
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} |
} |
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</syntaxhighlight> |
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</pre> |
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[[Category:Video]] |
[[Category:Video]] |
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[[Category:Hardware Detection]] |
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Latest revision as of 05:13, 9 June 2024
Detecting whether a user has a colour or monochrome video card is a trivial task. The BIOS data segment has a value in it for this information. Below is a function (in ISO C) to retrieve this:
The Function
#include <stdint.h>
enum video_type
{
VIDEO_TYPE_NONE = 0x00,
VIDEO_TYPE_COLOUR = 0x20,
VIDEO_TYPE_MONOCHROME = 0x30,
};
uint16_t detect_bios_area_hardware(void)
{
const uint16_t* bda_detected_hardware_ptr = (const uint16_t*) 0x410;
return *bda_detected_hardware_ptr;
}
enum video_type get_bios_area_video_type(void)
{
return (enum video_type) (detect_bios_area_hardware() & 0x30);
}