vga | 易学教程

How do I access memory addresses directly in Ada?

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问题 So I'm new to Ada, and I'm attempting to write a kernel in it, but I cannot seem to find any good information on how to do this properly. In C, I would write: unsigned char* videoram = (char*) 0xB8000; videoram[0] = 65; to access the video ram directly and write 'a' to it. I've heard I need to use an Ada array and other pragma's to do this in a typesafe manner in Ada. Is there any good resources on this kind of Ada programming? 回答1: You can use the 'Address attribute: Videoram : String (1 ..

Write graphics pixels in 16-bit assembly

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问题 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 graphics, 256 colors, 1 page) and tried several other modes like 01h and 03h but they don't work. This is my complete code: ;set video mode mov ah, 00h mov al, 13h int 10h ;write pixels on screen mov ah, 0ch mov bh, 0 mov dx, 5 mov cx, 5 mov al,

What is The Memory Address of Character Table In DOS? [closed]

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问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 8 years ago . What is the address of character table in DOS where we can create new fonts and symbols by manipulating the pixels of the each character? I know to change it with BIOS interrupts, but I only need the memory

VHDL VGA sync circuit

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问题 Can some one please tell me how this circuit increments h_count_reg and v_count_reg?? I don't really see it. Also what do they mean by the output is buffered exactly? It's just delayed by one pixel? don't really see that either. thanks! library IEEE; use IEEE.STD_LOGIC_1164.ALL; use IEEE.NUMERIC_STD.ALL; entity vgaController is Port ( clk : in STD_LOGIC; reset : in STD_LOGIC; hsync : out STD_LOGIC; vsync : out STD_LOGIC; video_on : out STD_LOGIC; p_tick : out STD_LOGIC; pixel_x : out STD

How do I print SVGA Info on the screen in tasm?

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I am complete beginner to assembly, and graphics, any help would be appreciated. I got the svga info, but when i print it, it won't print anything. If anyone can explain why that would be great. Here is the code. If there is anymore explanations needed for what I have done let me know .MODEL SMALL .STACK 64 .DATA getinfo: VbeSignature db 'VESA' ; VESA VbeVersion dw 0000h ; Version OemStringPtr dd ? ; Producer Capabilities db 4 dup (?); Reserved VideoModePtr dd ? ; Modes TotalMemory dw ? ; Blocks OemSoftwareRev dw ? OemVendorNamePtr dd ? OemProductNamePtr dd ? OemProductRevPtr dd ? _Reserved_

What is The Memory Address of Character Table In DOS? [closed]

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What is the address of character table in DOS where we can create new fonts and symbols by manipulating the pixels of the each character? I know to change it with BIOS interrupts, but I only need the memory address of the character table in dos for direct access. I can't remember how it was done any more (I did this stuff two decades ago), but you might want to look at the FreeVGA project . According to the text mode documentation you can select the address yourself (kinda; see the Character Map Select Register). Accessing that register is explained here . You might also want to look at this

iPad VGA Connector - Mirror screen in own Application?

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问题 Is it possible to mirror the Screen over the VGA Connector? Can't find anything about this. 回答1: I was looking for the same thing you are. Last weekend I wrote a small UIApplication category to add mirroring support. I published to code on Google Code. http://code.google.com/p/iphoneos-screen-mirroring/ To use it, you simply have to set it up in your application delegate's app did finish lauching. Like so: [[UIApplication sharedApplication] setupScreenMirroringOfMainWindow:mainWindow

iPad VGA Connector - Mirror screen in own Application?

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Is it possible to mirror the Screen over the VGA Connector? Can't find anything about this. I was looking for the same thing you are. Last weekend I wrote a small UIApplication category to add mirroring support. I published to code on Google Code. http://code.google.com/p/iphoneos-screen-mirroring/ To use it, you simply have to set it up in your application delegate's app did finish lauching. Like so: [[UIApplication sharedApplication] setupScreenMirroringOfMainWindow:mainWindow framesPerSecond:20]; I only had one chance to try it out last weekend on a big screen TV with the Apple AV output

Using UIScreen to drive a VGA display - doesn't seem to show the UIWindow?

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问题 HI there, I'm trying to use UIScreen to drive a separate screen with the VGA dongle on my iPad. Here's what I've got in my root view controller's viewDidLoad: //Code to detect if an external display is connected to the iPad. NSLog(@"Number of screens: %d", [[UIScreen screens]count]); //Now, if there's an external screen, we need to find its modes, itereate through them and find the highest one. Once we have that mode, break out, and set the UIWindow. if([[UIScreen screens]count] > 1) //if

Using UIScreen to drive a VGA display - doesn't seem to show the UIWindow?

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HI there, I'm trying to use UIScreen to drive a separate screen with the VGA dongle on my iPad. Here's what I've got in my root view controller's viewDidLoad: //Code to detect if an external display is connected to the iPad. NSLog(@"Number of screens: %d", [[UIScreen screens]count]); //Now, if there's an external screen, we need to find its modes, itereate through them and find the highest one. Once we have that mode, break out, and set the UIWindow. if([[UIScreen screens]count] > 1) //if there are more than 1 screens connected to the device { CGSize max; UIScreenMode *maxScreenMode; for(int i