What better way to keep your eyes off loads of work and stress than watching your favorite movie or streaming a film? The VGA technology makes this possible by providing a link between your computer and an output medium; It offers effective analog video signal transmission.
If this is your first time hearing about a VGA or you are just curious to know more about VGA, this is the post for you. We explore in detail how VGA works and, most importantly, give a brief history of this connection.
What is VGA?
VGA stands for Video Graphics Array. This is a standard connection used for video devices such as projectors and monitors.
VGA carries visual display data from a CPU to a display device such as a monitor or projector. A complete VGA cable carries a cable and connectors at each end. The connectors are usually blue.
One end of the cable is usually attached to the graphics card port on the computer motherboard, while the other end goes to the port in the display device.
When the source device is on, the video card transmits video signals through the VGA cable before being displayed on the display device.
Although VGA cables come in different types, the shorter type with a coaxial cable that is insulated provides a better quality video display.
VGA cables come in two different colors; beige and black.
When was VGA invented?
VGA was invented in 1987 by IBM as a video standard for computers. Its debuted display graphics card could display up to 16 colors at 4 bits per pixel depth and a screen resolution of 640 × 480 pixels.
Lower resolutions of 320 × 200 pixels could do up to 256 colors but as of now, it can easily reach 1080p Full HD.
Over the years, VGA resolution and colors have since been boosted by non-IBM vendors, who called these cables Super VGA. These resolutions are multiples of the total number of the debutant pixels in VGA.
The VGA cable can be used for 1080p high-definition resolutions and above and has since become a standard video output for projectors, laptops, monitors, and TVs.
For more than two decades now, the 15-pin VGA has remained relevant even after the entry of digital visual interfaces and digital monitors that can display thousands to millions of colors.
Before VGA, the common connections used were Color Graphics Adapter (CGA), Enhanced Graphics Adapter (EGA), and Monochrome Graphics Adapter (MDA).
However, none of them had an analog interface, and the number of colors was smaller with no displays of natural images. They were mostly used for games and business graphics.
Each of these used D-subminiature connectors, similar to the VGA but with fewer pins, 9 in number.
How VGA cables work
For your display to properly work, there are some support features that your VGA cables should have.
These include a color palette of 262,144 minimum value, 16 and 256 color mode support, a master clock speed of 25.175 or 28.322 MHz, up to 70 Hz refresh rates, a barrel shifter, a vertical blank interrupt, and split-screen support.
When you connect a VGA cable between a desktop computer and a monitor operating with the OS system, the device should automatically detect the VGA connection.
However, some laptops or computers may require you to manually send the display to the television or monitor by pressing the “Function” key.
The VGA cables use a three-row, 15-pin adapter to transmit video signals between your source and display devices.
When you connect a VGA cable to your device’s output, the RGBHV synchronizes and forms a unified video signal which can be split into multiple channels.
The video signal can then be viewed on monitors or other linked devices at the end of the VGA cable.
VGA cables also support Display Data Channel (DDC). They work with plug-and-play computer displays by enabling a video display to communicate to an adapter to allow adjustments of the computer host’s parameters such as contrast and brightness.
However, when working with VGA cables to connect a laptop or computer to a projector or a TV, you need to ensure that your laptop or PC output resolution matches the device’s resolution. This will give you clearer images.
Any wrong connection may result in blurred or stretched images. To avoid such a scenario:
- Set your computer’s output resolution or other source devices to match that of the display device.
- Check to ensure your display settings are set up correctly. If not properly set, your monitor may display nothing. If using your computer, try to boot windows using lower video resolution. For Windows 8 and 10 users, you can do this via the Enable low-resolution video option at the Startup settings section.
Features of VGA cables
Below are some of the important technical features of VGA:
As is with other types of cables, VGA is no exception; it takes on a specific gender—male or female.
The connectors on the male VGA cables stick out of the cable while those on the Female VGA are recessed. They have inward holes allowing a perfect fit with the male connection.
The VGA cable is available in different sizes ranging from 0.75 feet to 30 feet and more.
Another striking feature of VGA cables is the 15-pin connectors; five pins are positioned at the top, five are in the middle, and the other five are at the bottom. Each pin performs a specific function.
Typically, devices that use VGA have a port with the same number of pinholes allowing the VGA cable to plug into it directly.
The cable comes with two screws located at either end to help secure the socket onto the computer or monitor. They are designed to allow for hand-tightening without the need of using a screwdriver.
When displaying images, the VGA display standard uses analog signal technology. As such, the quality of video output may be poor.
VGA supports a resolution of 640 x 480 and has a refresh rate of 60Hz.
These cables come with different shielding. Some have double shielding, while others have triple shielding to help reflect energy and ground electrical noise.
How long has VGA been used?
First introduced in 1987, the VGA has been in use for the last 34 years. It was the most standard video interface for nearly two decades until HDMI was introduced in 2003.
Why is VGA still used?
Although VGA is an old connection type, you can not underestimate its usefulness. So prepare to bump into this technology in plenty of devices from time to time.
One of the reasons why VGA is still commonly used is that you can connect a VGA output and an HDMI input. And that is not all; an HDMI to VGA connection is also possible.
Standard VGA cables can establish reliable graphics and video links between monitors, projectors, computers, and high-definition TVs in both commercial and domestic setups.
Many people opt for VGA because of its reasonable prices compared to other transmission cables such as HDMI. VGA cables are widely available online.
VGA is found in most computers and projectors to receive an analog signal from a connected device. Although it does not transmit audio, it supports both standard and high-definition resolutions.
IBM was the first company to use VGA cables in its computers over 30 years ago. Other manufacturers soon appreciated these cables and adapted the technology in their devices as well.
Due to its relatively good price in the market, VGA technology is still widely used in many devices.