Screen communication from a 8K RAM
That's roughly how a normal screen works: that piece of RAM is called a framebuffer.

What's not shown is that there will be another piece of hardware reading from the RAM and refreshing the screen. For VGA video, this involves turning the digital value into an analogue value at precise times and sending out the pixels in sequence, corresponding to the path traced by the electron gun in a CRT display. "RAMDAC" is the term to look for here.

Various people have done VGA generation with microcontrollers, such as this page which also has some useful references: http://quinndunki.com/blondihacks/?p=955