Does what it says on the label, basically...
The VK5121 graphics display keeps popping up on eBay and end-of-line places. Basically it's horrible, but I foolishly designed it into a short-run hardware widget and needed to drive both text and graphical elements.
The graphical parts are highly specific to me and not worth discussing, but this demonstrates a way of using the display as a 4 line 20 character output.
Note that the routine 'lcd_print(char)' does not scroll the display and nor does it understand cr/lf/tab etc; it simply prints from top right to bottom left and then starts again.