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Questions tagged [vga]

Anything related to Video Graphics Array (VGA) video card and related standards. Usually used to tag questions about VGA compatible hardware (VGA connectors, cables, monitors, etc.) or VGA specifications (VGA resolutions, VGA video modes, etc.)

Anything related to Video Graphics Array (VGA) video card and related standards. Usually used to tag questions about VGA compatible hardware (VGA connectors, cables, monitors, etc.) or VGA specifications (VGA resolutions, VGA video modes, etc.).

See the VGA Wikipedia page.

257 questions
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will linux emit event when monitor connect with D-sub connector?

I want to write a software, when monitor connect with D-sub connector, this software will pop-up, and ask user to mirror monitor or extend monitor. but i doesn't find any event emit when d-sub connect. on Windows vista, if you connect a monitor,…
yurenju
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How to write into the VGA memory (not video buffer, memory) to display a logo on screen, in Linux?

I would like to write into the VGA memory (video memory, not buffer) from user space by mmap-ing in user space and sending the address to kernel space where, i would use pfn remap to map those mmap-ed address to the vga memory (i'll get the address…
neo
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Using the CGA/EGA/VGA planar graphics modes

I have trouble to grasp how to use colors in CGA/EGA/VGA video graphics modes. The video modes I'm particularly interested in are 0Dh (EGA 320x200) and 12h (VGA 640x480). Both of these modes have 4 planes, thus 16 colors. My (probably incorrect)…
MegaBrutal
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How does the default mouse cursor in MS-DOS work without erasing whatever is underneath it?

My understanding of VGA graphics may be flawed, but it seems to have only one layer of graphics, yet the mouse cursor in MS-DOS (or at least DOSBox) appears to be independent of the graphics beneath, much like a "sprite layer" on most video game…
puppydrum64
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color palette not working on certain colors in VGA

I'm trying to set the VGA(640x480x16) color palette in assembler on DOSBox but specifically colors 6, 8-F don't change. I have tried using interrupts and directly through ports both work for other colors but not for those. I'm using DOSBox 0.74-3 on…
Saar BS
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OSDev: Why does my VGA terminal scrolling not work?

I am developing an operating system as a personal hobby so I can learn about software engineering and computer architecture. I am trying to get the VGA terminal to "scroll" when text reaches past the bottom, or VGA_HEIGHT. I am using code from the…
Jonathan Dewein
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ASM: What does port 3c8h & 3c9h do?

I'm trying to create ASM code which will load and print an 256 color BMP file. I saw several codes that do this job, and they first load 0 to port 3c8h, and then load the palette to port 3c9h. What does the load to those ports do? Thanks in…
Idan
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Printing characters to screen ASM in protected mode

I'm trying to enter the protected mode and then print out "Hi" But instead it just prints "Loading OS" from my bios interrupt call (which happened before entering pmode) And nothing else. My Bootloader.asm %DEFINE KERNEL_LOAD_OFFSET 0x1000 org…
Jiří Velek
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Why do console OSes use gray text instead of white?

I often use operating systems without GUI, and I'm also developing mine. I've noticed that, although VGA 80x25 mode supports 0xF color, which stands for white, everyone uses 0x7, which stands for gray, for text color. Why doesn't one use white?…
Василий Свинко
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Write graphics pixels in 16-bit assembly

I'm trying to develop my own very basic operating system for educational purposes. While coding the kernel, I tried to set color to some pixels on screen to make it look better, but I failed. I used INT 10h with AH = 0CH with video mode 13h (320x200…
Moe
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How to find All Graphic Cards?

I used this code for finding graphic cards: ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT * FROM Win32_DisplayConfiguration"); string graphicsCard = ""; foreach (ManagementObject mo in searcher.Get()) { …
Mohammad
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Plotting a char in VGA mode

I´m working on a function to plot a character in video mode for the 256 VGA mode. I´m using 6x7 fonts with the set containing only the capital letters, numbers and signs. This is the data: uint8_t characters[455] = { …
Pablo Estrada
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Why can't I print "Hello World" on the screen of the physical machine?

I wrote an MBR program: section MBR vstart=0x7C00 mov sp, $$ ; initialize register mov ax, 0 mov ds, ax mov es, ax mov ss, ax mov fs, ax ; Set the address of the video memory to the es segment register. mov ax,…
aszswaz
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Word-sized OUT to a byte IO register? Setting the Sequence Controller Register with out instructions in old VGA code

I'm having trouble understanding how the Sequence Controller Registers are set in this example with some old VGA code: mov dx,SC_INDEX mov ax,0604h out dx,ax ;disable chain4 mode The example is from Michael Abrash's VGA book:…
thunder
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memcpy doesn't do anything

I was trying to put double buffering into my VGA dos program but it seems that there is a problem when I use the memcpy function. I'm sure that I allocate the required memory but it doesn't seem to work. Here is the program: #include…
alabdaly891
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