MDA (Monochrome Display Adapter) - the simplest video adapter, used in the IBM PC. Its official name is Monochrome Display.
The word monochrome reflects the most important characteristic of MDA. It was designed to work with a single color display. Initially he worked with screens green color, which were provided with almost all IBM systems of that time.
To center text entry current line is shifted by a few pixels equal to half the calculated offset. Listing 6 shows the procedure for displaying text on one or more lines using the align function. Function in full form should also take into account the orientation of the text and the scale factors used. Figure 6 shows an example of the display.
Bitmap fonts displayed on the display. The functions described above represent the core core of the graphics library. Using these primitives, you can implement more complex functions for drawing charts and histograms of control bars. The idea is to create macro functions that can handle most of the drawing operations, making the programmer's task easier. The result is shown in the figure.
Words "display adapter" are a functional description. This device converts signals traveling along the PC bus into a form that can be perceived by the video system. Possibility of connecting a printer To This adapter has its advantage because it allows you to connect a printer without using another expansion connector,
An example of a histogram display. To make the library more complete, you can create popup menus using popup mode. Realize animation through a logical combination of graphic pages and many other functions. As with televisions, screen size is determined by the diagonal distance between two opposite corners.
Computer video is very similar to television. The scheme used is called raster scanning and works like this: the screen is constantly "painted" by a moving electron beam that tracks a path along the entire screen, this starts in the upper left corner and runs along the first line of the image from left to right, illuminating the active parts of the screen, and then moving to the beginning of the next line.
MDA is a character system that provides no graphics other than the IBM extended character set. It was IBM's first adapter and, more recently, it was the best word processing adapter, providing the sharpest character display of any display system released before PS/2.
The beam passes from top to bottom until the image is complete. To minimize screen flicker, the image is played with double scans spaced very briefly. Television uses the same double scanning method.
Most video devices measure dot pitch in millimeters. Typical aspect ratios are 0.75 for computer monitors and 0.8 for television screens. Please note that in some cases typical resolutions are larger than calculated values.
As the screen size increases, the dot pitch decreases and the price of the device increases. However, the video adapter usually limits the number of colors that can be displayed, for example, if a byte of memory is used to represent the color of a pixel, 256 colors are possible for each pixel.
Text mode was the goal of the adapter's development. Back then, IBM couldn't imagine that anyone would want to draw diagrams on a display.
To ensure connection terminals, used in large computer systems, IBM For The character image in MDA used a screen area of 9x14 pixels, and the character itself was 7x9. Extra space was used to separate each character, increasing readability.
Likewise, if 24 bits per pixel is used, 16.8 million colors are available. Figure 3 shows how data in video adapter memory represents pixel colors. Modern video cards are not limited to controlling the output image. The built-in microprocessor has additional functions, which unload the computer processor.
Standard types of video adapters are used in computers and regulate key functions, such as resolution, number of colors, monitor interface type, and sampling rate. The presence of two video pages is standard for all video adapters and is actively used in games. While one page is displayed on the monitor screen, an image that is invisible to the user is created and then modified. Information on the screen requires synchronization with routing, otherwise there are conflicts in the video memory - “snow” on the screen. The number of colors displayed simultaneously is up to 16, the palette expands to 64 colors. An intermediate buffer is introduced for the data stream sent to the monitor, eliminating the need for synchronization when outputting text modes. The structure of video memory is built from the so-called bits, each of which in graphic mode contains bits only for its colors, and in text modes they are divided into layers into text and data for the character generator. Rotation speed - 15 and 18 kg. Interface with the monitor - analog-to-digital: digital clock signals, analog signals for primary colors transmitted to the monitor without sampling. Video adapter standard since the late 1980s.
- Rotation speed 15 kg.
- Rotation speed - 15 kg.
To implement the then video terminal standards that processed characters in 80 columns And!!<>rows, required 740 horizontal pixels and 350 vertical dots per screen.
When working with so many points!!ZM made five compromises. Displaying information at high frequencies would require a higher bandwidth monitor than was available (at least for little money) during the development of the PC. IBM slightly reduced the frequency used, bringing it to 50 Hz, And compensated for the possibility of screen flickering by using a phosphor with a large residual glow. Thus, the IBM monochrome display standard was born.
A graphics accelerator is a video adapter in which a number of graphics functions are performed at one level - moving image blocks from one area to another, filling image sections, drawing lines, arcs, fonts, cursor support and much more. The graphics accelerator offloads the CPU to do most of the calculations needed to display and control the screen image. A modern graphics card consists of the following parts.
The main element on which the performance and capabilities of the entire device depend. Modern GPUs on a PC CPU are a bit slower and often outnumber the transistors. In addition, they typically include an external data bus controller, a data bus controller, and a video memory controller. Modern graphics adapters usually have at least two video controllers that operate independently of each other and simultaneously control one or more displays. Video memory - plays a frame buffer that stores a digital copy of the image generated and constantly modified GPU and displayed on the monitor screen. Video memory also stores intermediate pixels and non-viewable images. Video memory comes in several types, differing in access speed and operating frequency. The second DAC is used to support the second monitor. The video driver acts as an interface between the system and applications and the video adapter. General structural scheme shown in Fig.
Hercules
HGC (Hercules Graphics Card - graphic Kapia Hercules) is an MDA extension with a 720x348 graphics mode, developed by Hercules.
CGA- color graphics adapter
The first raster display adapter developed by IBM for the PC was a color graphics adapter - CGA (Color Graphic Adapter). The presented alternative to MDA dazzled the computer world, accustomed to green. The new adapter provided 16 bright, pure colors. In addition, he had the ability to work in several graphic modes with different resolutions.
Memory bus width, measured in bits - the number of bits transferred per second. . The first bottleneck in video system performance is the data interface to which the video adapter is connected. If the communication links between the CPU, CPU, RAM, and additional video devices are slow, the performance of the video display will be poor.
In addition to the data bus, the second big consideration for every video adapter is its native video memory performance. Each image is first saved on the video card of the video adapter. You need to read the information on the screen. The problem is solved by using special types of memory, allowing two devices to simultaneously read or use very fast memory: Allows the video terminal to match the image on the screen and its processing in video memory. After the first memory read or write, the following such operations have null value- is achieved maximum speed reading and writing.
Information display devices 285
As the name of the adapter suggests, it was intended to form graphic image on a color screen. However, it also supported non-IBM monochrome displays for the MDA board. It could work in tandem with monochrome and composite monitors, and even with a television receiver modulator. (However, you cannot connect the CGA to a TV unless the latter has a composite video input.) Also provides light pen functionality.
One memory chip can be inserted into one of these channels. The disadvantage of memory is the need to read information about large blocks, otherwise performance decreases. They say that in order to predict the future, you need to know the past. Following this wisdom, we decided to take a look at the history of some of the hottest and trendiest devices in recent times - smartwatches. And while we were preparing the material, we discovered that the roots of this idea in the past were much further back than originally thought.
In any case, it is of course interesting to see where the smartwatch is and how it goes to get to smart watch. Although we continue to use these two terms interchangeably as synonyms, the distinction is necessary because there is a difference in the perception of the concepts. Initially, the term "smartwatch" covered every handheld accessory capable of not only displaying current time and date. However, in the modern sense, a “smart watch” is an electronic device that actively interacts with smartphones or directly with Internet services.
CGA is a multi-mode display adapter. It can be used for both character and bitwise technologies. For each of them, it implements several modes. It contains 16 KB of memory directly accessible to the central microprocessor.
The character mode of CGA operation is set by default. In this mode, CGA functions similar to MDA. The main difference between these two adapters is that the second one was designed to work with non-standard vertical and horizontal frequencies, providing a clearer image. CGA operates at standard frequencies - those used by composite displays. This makes it possible to be compatible with a large family of monitors, but at the same time reduces image quality.
But let's not delay the retrospective. Sometime in the 19th century, personal watches - then pocket watches rather than hand watches - became almost a mandatory accessory for gentlemen of decent social standing. At that time, pocket watches were a sign not only of material well-being, but also of good taste. And the more expensive representatives of this time measurement technique were handed down as family heirlooms from father to son.
Pocket bags are historically the first watches to be worn. This lasted a long time - until the second half of the 20th century, when smart wristwatches began to appear - long before the arrival mobile phones. These electronic devices turned out to be quite successful and even showed up in movies - in one of the James Bond episodes.
CGA divided the display into a matrix of 640 horizontal pixels and 200 vertical ones. To fit 2000 characters onto an 80x25 character screen in MDA format, 8x8 pixel cells are used.
In CGA systems, each character is arranged in a 7x7 matrix. One dot is reserved for the sublinear element and another for the separator. Obviously, the subline element extends across the entire image, which avoids additional lines to separate lines of text. Using fewer dots when drawing a character means that the image will have a rougher and less pleasing shape compared to MDA.
The era of the first Japanese smart watches. In the current electronic device It can store text up to 24 characters long, making it suitable for taking short notes. Compared with previous model The memory capacity was reduced to 112 characters, but the designers were able to get rid of the bulky dock and create a mini keyboard that was part of the watch itself. Huge functionality of the 80s of the twentieth century.
The era of US IT giants. At the dawn of the new millennium, the idea of a smartwatch as a personal electronic assistant also intrigued American computer giants. Its main goal is to make smart home appliances and wearable gadgets using special applications. Even Bill Gates himself was a fan of this project. The situation today is in anticipation of tomorrow.
In any IBM text mode, you can manipulate attributes to work with a 16-color palette. Any text character can be depicted in any of 16 colors.
The shape of the symbol - the points included in the 8x8 matrix of the symbol and not participating in the formation of the symbol - can also have one of 16 colors, but with one limitation. In the default mode, 8 colors can be used for the background because the bit in the parameter byte that sets the brightness or intensity of the background color is intended for a different purpose. It is used to set the blinking mode of the symbol.
The new life of “smart watches” begins with the so-called post-computer era, when it finally becomes possible to create not only miniature, but also powerful electronic gadgets, able to connect to the Internet anywhere and anytime. And while it is fashionable to talk mostly about “portable electronics,” smartwatches are definitely dominating this segment as they are coming in quite mature and interesting forms.
And since last year's open OS platform and the watches based on it were received with great interest and even enthusiasm from the general public, the future of smartwatches is looking rosier than ever. Indeed, as can be seen from the current retrospective, manufacturers have been making great strides with smartwatches for a long time. Now this word has consumers. Because no matter how interesting a widget is, it simply won't survive if it isn't supported by enough market demand.
The special register CGA changes the purpose of this bit. Loading certain values In this register, the user or program can choose between flickering or displaying the background color with increased intensity. However, this register controls all the text on the screen, so it is not possible to use both flickering characters and increased background color intensity at the same time.
E.G.A.- improved graphics adapter
By 1984, the shortcomings of the CGA had become apparent. This was revealed due to its wide distribution. Hard-to-read text and crude graphics spoiled vision faster than any other device.
As a response to well-deserved criticism, an improved graphics adapter appeared - EGA. The improvement was multifaceted: increased resolution, the ability to provide graphics mode for monochrome screens, including IBM's favorite green displays.
The most significant change is clearly visible in the generated image. Resolution has been increased to 640x350 pixels. Character cells are 8x14 in size. And although such a cell is one point narrower than that supported by MDA, the symbol is formed by the same 7x9 matrix. But more importantly, enough space was allocated for sublinear and superscript space. Thanks to this, adjacent rows did not merge and color image text was perceived just as well as monochrome.
A resolution of 640x350 was provided in graphics mode. This adapter could also support all graphics modes of previous IBM adapters. This means that the EGA is capable of providing all the modes of the legacy CGA.
The capabilities of the EGA standard for creating a color gamut have increased significantly. By changing the adapter-display interface, the realized EGA palette was expanded to 64 shades (counting black and various shades of gray as separate colors). In addition, due to the presence of a large memory resource, the EGA standard is able to support a wider palette of colors with a higher level of resolution. In maximum resolution mode and full use of memory resources, EGA is able to simultaneously generate images in 16 color shades, selected from a 64 color palette on a 640x350 pixel screen.
MCGA- multicolor graphics adapter
MCGA (Multicolor Graphics Adapter) was introduced by IBM in early PS/2 models. The number of reproduced colors has been increased to 262,144 (64 levels for each of the primary colors). In addition to the palette, the concept of a color table has been introduced, through which the 64-color EGA color space is converted to the MCGA color space. A 320x200x256 video mode has also been introduced, in which, instead of bit planes, the screen is represented as a continuous memory area of 64,000 bytes, where each byte describes the color of the corresponding point on the screen. Compatible with CGA in all modes and with EGA in text modes, except for the size of the character matrix. Interface with the monitor - analog-digital: digital signals synchronization, analog, primary color signals transmitted to the monitor without sampling. Supports the connection of a monochrome monitor and its automatic recognition, while the video BIOS turns on the mode of summing colors according to the so-called gray scale to obtain a halftone black and white image. Summation is performed only when outputting through the BIOS: when directly writing to the video memory on the monitor, the popup produces only a green signal (if it Not has a built-in color mixer).
VGA - Visual Graphics Array
VGA (Video Graphics Array) - MCGA extension, compatible with EGA, introduced by IBM in mid-range PS/2 models
Computer science
Exactly the same as V previous systems, VGA provides different levels of resolution in various modes functioning. But VGA provides much large quantity modes. Their total number is 17. However, in graphic and text modes, different levels of resolution are achieved.
In graphic modes, when forming a raster Color image, a resolution of 640x480 pixels is achieved. In this case, 16 colors are formed, selected from a palette of 256. The same level of resolution is provided for a monochrome image.
The move to a 640x480 pixel standard from the EGA standard (640x350) has improved image accuracy. The VGA standard allows you to create more accurate images using a larger gamut of colors. The ratio of horizontal to vertical pixels (4:3) is favorable because it is equal to the screen aspect ratio of most monitors.
The new standard is capable of supporting 256 screen colors simultaneously. Colors are selected from a palette of 262,144 shades. In this mode, the resolution is limited to 320x200 pixels. This resolution is CGA operating in medium resolution mode, but the latter can work simultaneously with four colors selected from a palette of 16 colors.
An information visualization device is a display with a monochrome (one-color) screen.
- - a device for visually displaying information, usually on the screen of an electron beam device...
Agricultural Encyclopedic Dictionary
- - - single color...
Encyclopedia of fashion and clothing
- - a device for visually displaying information, usually on the screen of a cathode ray device...
Big Encyclopedic Polytechnic Dictionary
- - a device for visually displaying information primarily on the screen of a cathode-ray device...
Modern encyclopedia
- - a device for visually displaying information primarily on the screen of a cathode-ray device...
Large encyclopedic dictionary
- - display noun, m., used compare often Morphology: what? display, why? display, what? display, what? display, what about? about the display...
Dmitriev's Explanatory Dictionary
- - ; pl. display/s, R....
- - ...
Spelling dictionary of the Russian language
- - DISPLAY, - I, husband. . A device that displays information received from a computer on the screen, an on-screen remote control...
Ozhegov's Explanatory Dictionary
- - display m. 1. A device for visually displaying information in the form of text, tables, drawings, etc., based on the use of a cathode ray tube or liquid crystals; video monitor, monitor...
Explanatory Dictionary by Efremova
- - monochrome adj. the same as...
Explanatory Dictionary by Efremova
- - ...
Spelling dictionary-reference book
- - monochrome "...
Russian spelling dictionary
- - MONOCHROME oh, oh. monochrome, German monochrome. Single color, monochromatic. Monochrome image. Monochrome photo. BAS-1...
Historical Dictionary of Gallicisms of the Russian Language
- - monochrome one-color; m-th painting is painting done in one color...
Dictionary of foreign words of the Russian language
- - ...
Word forms
"Monochrome display" in books
Display
From book Great encyclopedia technology author Team of authorsDisplay A display is a device for editing, entering and visually presenting information on the screen without their long-term preservation. The display consists of a keyboard, monitor and (possibly) a printer. There are graphic and character displays. It could be a terminal
1963 PAL system, on TV - the Beatles, TV in Chita, worldwide communication system, calculator, surfactant, LCD display, Philips compact cassette, tragedy in Dallas
From the book Popular History - from electricity to television author Kuchin Vladimir1963 PAL system, on TV - the Beatles, TV in Chita, worldwide communication system, calculator, SAW, LCD display, Philips compact cassette, Dallas tragedy In 1963, in early January, engineer Walter Bruch proposed color television coding PAL method. In 1963, January 19, on
Speeding up the display
From book Windows Registry author Klimov AlexanderSpeeding up the display To store on-screen characters, the PDA uses a special cache, which can serve as a source of slow display rendering. You can increase the size of this cache. To do this, you need to change the Dword °limit° parameter in the HKLM/System/GDI/GLYPHCACHE section. Values
Monochrome mode (Bitmap)
From the Photoshop book. Multimedia course author Medinov OlegMonochrome mode (Bitmap) In this color model there are only two colors: white and black, without any intermediate shades (Fig. 1.3). Rice. 1.3. Bitmap So if you try to represent grey, blue or any other color in this model,
Monochrome color mode
From book Adobe Photoshop CS3 author Zavgorodniy VladimirMonochrome color mode The simplest and most primitive color mode is Monochrome, which uses only two colors. The name “monochrome” suggests one color (mono – “one”, chroma – “color”), but the second is like a “background” on which we draw with one
Display
From the book Laptop [secrets effective use] author Ptashinsky VladimirDisplay Need I say that comfort when working at a computer is largely determined by the quality of its display? In a stationary system, you can always replace a monitor that does not suit you according to its parameters. With a laptop the situation is different: the mobile display
New iPhone: ultra-clear display, video chat and Farmville Mikhail Karpov
From the book Digital magazine "Computerra" No. 20 author Computerra MagazineNew iPhone: ultra-clear display, video chat and Farmville Mikhail Karpov Published June 08, 2010 WWDC is the annual Apple developer conference, where company representatives show new devices, software and technologies. With its approach to
Sharp and Qualcomm showed a new generation display Andrey Vasilkov
From the book Digital magazine "Computerra" No. 193 author Computerra MagazineSharp and Qualcomm showed a new generation display Andrey Vasilkov Published October 01, 2013 At the annual Japanese CEATEC exhibition, Sharp demonstrated a prototype display developed jointly with Qualcomm. It lacks the usual
Samsung SGH-F250: If not for the display...
From the book Computerra Magazine No. 727 author Computerra MagazineSamsung SGH-F250: If it weren’t for the display... Author: Alexey Starodymov + “expensive” design, advanced music capabilities, support for call profiles - weak screen, just one menu theme Samsung is expanding its line of music phones with all its might, and its next
Your Constant Emotional Display
From the book Music of the Brain. Rules for harmonious development by Pren AnetYour Constant Emotional Display What happens when two people find it unusually easy to communicate with each other? They listen, move their arms and legs, twirl their hands, fiddle with clothes, and do much more. But they do all this in a special way: their movements are rhythmic
