This week we are going to look at the DVI connection: what it is and why it came to be. DVI stands for Digital Video Interface. DVI was invented with the intention of replacing VGA as the standard and to take advantage of newer digital monitors. Something I forgot to talk about last week is the fact that VGA connections started because early monitors only operated in an analog format. These were the old CRT or tube monitors that could not accept a digital signal. Now almost all plasma, LCD and LED monitors accept a digital signal. DVI ports and cables were created to transfer digital signals directly to a digital monitor.
The two most common types of DVI ports are DVI-D (digital) and DVI-I (integrated). DVI-D is only capable of transferring a digital signal whereas DVI-I can transfer digital and analog signals to a monitor that will accept both through the DVI port. You may also encounter a DVI-A port, which is an analog only DVI connection, however, this is rare.
You can also get an adapter to change a VGA connection to DVI but you have to be very careful about what you can and cannot do. I will be discussing this in a later segment, as compatibility is becoming a real problem on the show floor. Laptops and monitors are limiting the types of connections to analog only or digital only. Monitors are becoming lighter and thinner and many do not have the VGA port to accept an analog signal anymore. Enough on that for now ─ just know that I will be covering this in depth in a later blog
Ok, back to the DVI port and connector.There are two types of DVI port: dual link or single link. Most monitors will have single link ports which can display a 1920 x 1080 image. Dual link connections can support a 2048 x 1536 image. You can tell if your connector is a single link or a dual link since a single link has a gap between the two squares of 9 pin for a total of 18 pins. The dual link has three solid rows of 8 pins for a total of 24 pins.
So how do you tell if your computer or monitor will send and receive an analog signal through the DVI port? You need to look at the port to see if there are two slots for pins above and below to large horizontal slot. These four pins are for the analog connection.
Now there are also mini and micro DVI connections and cables but we will leave that to the Apple computer people of the world to understand.
Image Source: Wikipedia