|Digital Visual Interface (DVI)|
It is partially compatible with the High-Definition Multimedia Interface (HDMI) standard in digital mode (DVI-D), and VGA in analog mode (DVI-A).
DVI and HDMI compatibility
HDMI is a newer digital audio/video interface developed and promoted by the consumer electronics industry. Both DVI and HDMI share the same electrical specifications for the TMDS and VESA/DDC links. However, HDMI and DVI differ in several key ways.
First, HDMI lacks analog VGA compatibility, as these signals are absent in the HDMI connector.
Second, DVI is limited to the RGB color space, whereas HDMI supports both RGB and YCbCr.
Finally, HDMI supports the transport of digital audio, in addition to digital video. An HDMI source differentiates between a legacy DVI display and an HDMI-capable display by reading the display's EDID block.
The DVI connector on a device is therefore given one of three names, depending on which signals it implements:
* DVI-D (digital only, both single-link and dual-link)
* DVI-A (analog only)
* DVI-I (integrated - digital and analog)
Virtually all actual video CARDS, that you install in a mboard slot and can remove, that have a DVI port, and MOST mboards that have a DVI port for onboard video, have a DVI-I port - a standard DVI to VGA gender adapter, or a standard DVI-I to VGA cable, WILL work with the DVI-I port to provide a VGA (analog) video signal to a monitor.
SOME mboards that have a DVI port for onboard video have a DVI-D port - a standard DVI to VGA gender adapter, or a standard DVI-I to VGA cable, WILL NOT work with the DVI-D port to provide a VGA (analog) video signal to a monitor.
If you use a DVI-D cable connection, or if the monitor has a DVD-D port, you cannot get VGA (analog) video from the video adapter..
"I have a computer with a video card that has HDMI output. I have a HDMI cable connecting the computer to the monitor. I can see analog AND digital signals just fine."
"I don't understand why the HDMI, which is supposed to be digital, shows the analog signals while booting; you think it would not."
I don't understand that either.
Are they HDMI ports on both ends of the connection ?
Or -are you using a gender adapter on the monitor end to adapt it to a DVI port ?
Or what ?
Does the first monitor have both VGA and HDMI ports, or both VGA and DVI-I ports, and you had both connected ?
Usually, if not always, the monitor will accept only one type of video input at a time. If you had both connected, you were probably getting VGA video.