The only problem is that when assigning in lcd.begin (100, 16) the display does not reproduce letters correctly. Is there a way to fix it or am I limited to using it as a normal 16x2 display? Thanks!
The controller is Raystar RS0010 which obeys most of the HD44780 character LCD commands and behaviour.
The geometry looks like a 16x2 Character LCD. e.g. 5x8 font with 1 pixel gap means that you get 16 letters. i.e. it seems more like 96x16 pixel Graphics display. You might get an extra 4 columns to achieve 100x16 but the photos look like 96x16.
It also has a Graphics mode which should be pretty easy to use.
However I am not aware of any specific Arduino library for Raystar RS0010 or Winstar WS0010.