Digital Visual Interface

A special cord helps your screen work. It sends pictures from a computer to a monitor. This cord is called DVI. It sends digital pictures to make them look clear.

Some DVI cords can also send old types of signals. This lets them work with older screens.

You can use a small tool to help them connect.

Some cords have a single link. Others have a dual link. A dual link sends more data. This makes the picture even better. It is a great way to see your movies.

DVI is a way to connect video. It sends pictures from a computer to a monitor. This system was made to send digital video. It does not squeeze the video data. This keeps the picture clear.

There are different types of DVI plugs. A DVI-D plug is digital only. A DVI-I plug is special. It carries both digital and analog signals.

This lets it work with older screens. You can use a small tool called an adapter to help.

This tool lets a DVI-I plug fit into a VGA screen.

DVI uses a fast way to send data. It uses TMDS. This stands for transition minimized differential signaling. This method helps stop electrical noise. It keeps the signal strong.

Some DVI cords use a single link. These can show a screen of 1920 by 1200. Other cords use a dual link. A dual link adds more pins. This lets it send much more data. It can show a screen of 2560 by 1600.

Digital Visual Interface, or DVI, is a way to connect video sources to screens. It acts like a path for video data. This path connects things like a video controller to a computer monitor.

The goal was to create a standard for sending uncompressed digital video. Uncompressed means the video is not squeezed or changed. This helps keep the picture very clear. DVI is mostly used for computers. However, you might also find it on DVD players or television sets.

How DVI works depends on a method called TMDS. This stands for transition minimized differential signaling.

TMDS uses twisted pairs of wires to carry pixel data. These pairs help protect the signal from electrical noise. A single link connection uses four TMDS pairs. Three pairs carry color data for red, green, and blue. The fourth pair carries a clock signal to keep everything in time. This single link can show a screen of 1920 by 1200 pixels.

To show even bigger pictures, DVI uses a dual link. This version doubles the number of TMDS data pairs. This effectively doubles the video bandwidth, which is the amount of data that can move. Dual link can support much higher resolutions. It can show a screen of 2560 by 1600 at 60 Hz.

Some DVI plugs are digital only, called DVI-D. Other plugs, called DVI-I, are integrated. This means they carry both digital and analog signals. This allows them to work with older analog VGA monitors using a simple adapter.

Many different groups tried to make video standards before DVI became popular. In 1994 and 1995, VESA made the Enhanced Video Connector, or EVC. Later, VESA released the Plug & Display standard in 1997. There was also a group that made the DFP standard in 1999. DVI was developed by the Digital Display Working Group. It started appearing in products in 1999. One of the very first DVI monitors was the Apple Cinema Display.

DVI is like a smart messenger between a computer and a screen. It uses a system called DDC to talk to the monitor. This allows the computer to read the monitor's identification data. This data tells the computer the color traits and the best video modes to use. It is much like how a person reads a label on a box to know what is inside. Because DVI can use both digital and analog signals, it bridges the gap between old and new technology. This helped it become a very successful industry standard.

The Digital Visual Interface, commonly known as DVI, is a video display interface. It was created to connect a video source to a display device. A video source is often a video display controller. The display device is usually a computer monitor.

The Digital Display Working Group (DDWG) developed DVI. Their goal was to create an industry standard for transferring uncompressed digital video content. This means the video data is not squeezed or changed during the transfer. This high level of fidelity ensures the image remains clear. While DVI is mostly used for computers, it also appears in other electronics. You might find DVI ports on television sets or DVD players.

DVI uses a specific method to move data called transition minimized differential signaling, or TMDS.

This is a high-speed serial link. TMDS transports digital video pixel data using multiple twisted pairs of wires. These twisted pairs are very important for signal quality. They are highly resistant to electrical noise and other forms of analog distortion. This helps keep the digital signal clean as it moves from the source to the screen. The system does not use packetization. Instead, it transmits pixel data as if it were a rasterized analog video signal. This means a complete frame is drawn during each vertical refresh period.

There are different ways a DVI connection can be configured. A single link DVI connection uses four TMDS pairs. Three of these data pairs carry the 8-bit RGB components. These represent the red, green, and blue parts of the video signal. Together, these three pairs provide 24 bits per pixel. The fourth pair carries the TMDS clock to keep the timing correct. Single link mode has a maximum TMDS clock frequency of 165 MHz. This supports a maximum resolution of 2.75 megapixels at 60 Hz. For most users, this means a maximum resolution of 1920 × 1200 at 60 Hz.

To support higher-resolution devices, the DVI specification includes a dual link option. Dual link DVI doubles the number of TMDS data pairs. This effectively doubles the available video bandwidth. This extra capacity allows for much higher resolutions. Dual link can support resolutions up to 2560 × 1600 at 60 Hz. It can also support higher refresh rates for lower resolutions. Dual link DVI adds six pins at the center of the connector. These extra pins allow for a second transmitter. Some people call these connectors DVI-DL. It is important not to confuse dual link with dual display. Dual display refers to connecting one computer to two separate monitors.

DVI connectors are categorized by the types of signals they carry. There are three main types: DVI-I, DVI-D, and DVI-A. DVI-I stands for integrated. These connectors combine both digital and analog signals in one plug. They include VGA pins for analog compatibility. DVI-D is digital only. It can be either single link or dual link. DVI-A is analog only.

Most DVI connectors, except for DVI-A, carry digital video signals. Because DVI-I carries analog signals, it is compatible with the analog VGA interface. You can use a simple, cheap passive adapter to connect a VGA monitor to a DVI-I source. However, a DVI-D output requires a more expensive active adapter to work with VGA.

The history of DVI involves several competing standards. In 1994 and 1995, VESA created the Enhanced Video Connector, or EVC. The EVC used a 35-pin Molex MicroCross connector. It carried analog video, analog stereo audio, and data via USB or FireWire. Later, VESA released the Plug & Display (P&D) standard in 1997. P&D used the same 35-pin connector but focused on digital video. A different group developed the Digital Flat Panel (DFP) standard in 1999. DFP used a 20-pin micro ribbon connector and only sent digital video. DVI succeeded because it could support dual-link TMDS signals. This allowed for higher resolutions than P&D or DFP. DVI began appearing in products in 1999. One of the first DVI monitors was the Apple Cinema Display.

DVI also includes a smart communication system called the display data channel, or DDC. The DDC allows the graphics adapter to read the monitor's extended display identification data, known as EDID. When you connect a source and a display, the source queries the display's capabilities. It reads the EDID block over an I²C link. This block contains the monitor's identification and its color characteristics, like its gamma value. It also contains a table of supported video modes. Each mode tells the computer the resolution, the refresh rate, and the timing values. This ensures the computer and the monitor can work together perfectly.