Before you start
Objectives: Learn which interfaces we can use to connect various video adapters and display devices.
Prerequisites: no prerequisites.
Key terms: cable, analog, dvi-d, pin, hdmi, monitor, displayport, dvi-i, male, vga, audio, dvi-a, composite, connection, digital, output, s-video, crt, d-sub, dms, dual-link, hdtv, din, dvi
A D-sub (also called VGA) connector uses a DB-15 connector with three rows of pins. This connector provides analog output. Using this connector we can connect an analog CRT monitor or an LCD monitor that accepts an analog connection.
Image 323.1 – DB-15 (three rows), Male (left), Female (right)
For some LCD monitors we might need a cable with a VGA connector on the PC-end, and a DVI-A connector on the display end. Also, if we have a DVI-A connection on our video card and we want to connect our CRT monitor (VGA), we will also use a cable with a VGA connection on one end and a DVI-A connection on the other end. DVI-A connector (Digital Video Interface – Analog) provides analog output. DVI-A connections are rarely used for computers monitors, but might be used on some HDTV systems.
Image 323.2 – DVI-A and VGA
A DVI-D or DVI-Digital connector provides digital data transfer. DVI-D connections can be single-link or dual-link. Single-link connectors have three rows of 6 pins with one additional larger horizontal pin. Single-link can support a refresh rate of 60 Hz and up to 1920×1080 lines of resolution.
Image 323.3 – DVI-D Single Link Male
Dual-link DVI-D connectors have three rows of 8 pins, plus the horizontal pin. It is often called a 25 pin, 24+1 pin, or 24 pin connector. Dual-link can support a 60 Hz refresh rate and up to 2048×1536 lines of resolution. With dual-link DVI-D connectors we can use longer cables and a higher video resolution.
Image 323.4 – DVI-D Dual Link Male
We can only connect a digital monitor to a DVI-D connector. We can connect an analog monitor such as a CRT only by using a special converter, but that converter can be pretty expensive. It is possible that we find a CRT monitor with DVI-D connector, but that is rare.
A DVI-I or DVI-Integrated connector can provide analog and digital output. The DVI-I connection has all the pins present in both the DVI-A and DVI-D connectors. Using DVI-I we can connect an analog CRT or LCD monitor using a cable with a D-sub connector on one end and a DVI-A connector on the other. Also we can connect an LCD monitor with either a DVI-I or DVI-D cable. DVI-I cable can also be a single-link or dual-link.
Image 323.5 – DVI-I Single Link Male
Image 323.6 – DVI-I Dual Link Male
The DMS-59 connector sends two separate DVI-I signals on a single connector. It uses a special cable that splits the signal into separate video interfaces. For example, the cable might split the signal into two DVI-I connectors, two D-sub connectors, or one DVI-I connector and one D-sub connector.
Image 323.7 – DMS-59 Male
A composite video connection provides analog video-only. It uses RCA connectors. We can use composite video connection to connect a TV, VCR, or video camera to our video card. Note that audio signal in this case must be supplied separately. The connector is typically yellow.
Image 323.8 – Composite Video Cable
S-video (Separate-video) connections supply analog video TV output. The S-video connector is a 4-pin mini-din. S-video can be converted to composite by combining its channels into a single signal.
Image 323.9 – S-Video Male
7 Pin Mini DIN (HDTV)
7 pin mini DIN is an HDTV connector which supplies analog video output in three separate channels: red, green, and blue. Video cards with 7 pin mini DIN output usually include a cable that converts the 7 pin connector into three RCA cables which we can use for connecting an HDTV device. With this type of cable audio must be supplied separately.
Image 323.10 – 7 Pin Mini DIN
HDMI or High-Definition Multimedia Interface is a digital video and audio connector used for high-definition digital audio and video. HDMI combines the audio and video signals onto a single cable, but not in all cases. For example, if we use a DVI-to-HDMI cable to connect the output from a video card to a monitor or an HDTV device, we will only supply video to the device, and not audio. DVI and HDMI are electrically equivalent, which means that a simple pin-to-pin adapter is all that is required to connect a DVI device to an HDMI port.
Image 323.11 – HDMI Male
DisplayPort is an alternative to an HDMI connector. It is used to connect high-end video cards and displays as well as home theater equipment and displays. DisplayPort uses digital signals, so to connect a VGA monitor to a DisplayPort, we will need a special active converter that reformats the signal for analog devices. DisplayPort can also send audio signals over the same cable. However, the DisplayPort actually supports fewer features than HDMI.
Image 323.12 – DisplayPort Male
F-type connector is used on coaxial cables for cable TV or satellite TV input, and also audio input.
Image 323.13 – F-type
Common video interfaces are D-sub or VGA, DVI, DMS-59, Composite video, S-video, HDTV, HDMI, F-type, and DisplayPort.