What is the full form of VGA
VGA: Video Graphics Array
VGA stands for Video Graphics Array. It is a display hardware developed by IBM in 1987. It was first introduced with IBM PS/2 line of computers. It provides a resolution of 640×480 pixels and a refresh rate of 60 Hz.
VGA is referred as an array instead of an adopter because it was implemented from the start as a single chip (ASIC). It uses analog signals rather than digital signals.
Technical Specifications
The original VGA has the following specification:
- 256 kB Video RAM
- 16-color and 256-color paletted display modes.
- 262,144-color global palette (6 bits, and therefore 64 possible levels, for each of the red, green, and blue channels via the RAMDAC)
- Selectable 25.175 MHz or 28.322 MHz master pixel clock
- Usual line rate fixed at 31.469 kHz
- Maximum of 800 horizontal pixels
- Maximum of 600 lines
- Refresh rates at up to 70 Hz
- Vertical blank interrupt
- Planar mode: up to 16 colors (4-bit planes)
- Packed-pixel mode: 256 colors (Mode 13h)
- Hardware smooth scrolling support
- No hardware sprites,
- No Blitter, but supports very fast data transfers via “VGA latch” registers.
- Barrel shifter
- Split screen support
- 0.7 V peak-to-peak
- 75 ohm double-terminated impedance (18.7 mA, 13 mW)
Shape and Size
A VGA connector is shaped like a trapezoid and it has 15 pins. If you have a old monitor designed for the older standards may not be able to work with Video Graphics Array standards.
Compatibility
The older VGAs provide a resolution of 640×480 pixels. After that version, many revisions have been introduced. The most common version of VGA is Super VGA (SVGA). It allows for resolutions greater than 640×480, such as 800×600 or 1024×768.