Plato III - 1968

Hello, readers, please don’t eat me alive in working to understand a thesis published in 1968 UIUC. I am looking to understand how [the] ‘arrow’ keys moved an accessible cursor independently of line feeds and characters. I believe this programming on a keyboard was addressed to help students to better understand how to learn mathematics. The interesting concept was that this programmer used 8 keys, rather than 4 keys (up, down/left,right) to address diagonal references. Some reference that this used assembler/compass for programming. Further reference: Max Beberman, New Math Curriculum, University of Illinois, Mathematics. Again, please don't eat me alive, I am looking to understand arrow keys on the Plato III system that were used to further mathematics education in 1968. Early Plato People reading, Friday nights playing Empire, thank you.