What is VGA, and how does it work?
OK, the answer to this one could easily be a book (actually, see the references because it _is_ a book or several). I’ll give a very cursory overview of what the VGA is capable of. The Video Graphics Array is a standard established by IBM to provide higher pixel addressability, colour graphics than are available with EGA. In fact, VGA is a superset of EGA, incorporating all EGA modes. The VGA consists of seven sub-systems, including: graphics controller, display memory, serializer, attribute controller, sequencer and CRT controller. Basically, the CPU performs most of the work, feeding pixel and text information to the VGA. Graphics Controller: Can perform logical functions on data being written to display memory. Display Memory: A bank of 256k DRAM divided into 4 64k colour planes. It is used to store screen display data. Serializer: Takes display data from the display memory and converts it to a serial bitstream which is sent to the attribute controller. Attribute Controller: Contain
