You need to find out about the VESA and Super VESA standards. Although todays video cards are alot more advanced these standards are the starting point where high res graphics are concerned.
Basically the VESA standards are an extension of the BIOS interrupt 010h where you can directly control the video card.
every good assemblist has a copy of the BIOS interrupt usage (most probably ralf browns), processor programming manuals (most probably Intels), operating system - system calls.
Drawing lines and circles, you have to do that the hard way with the VESA standard although some cards at the time and certain alot more suppprt additional functionality.
All this information is freely available on the web, you just have to find it!
"People who have nothing to say, say it too loud and have little knowledge. It's the quiet ones you need to worry about!"
