can't control/style font on sp742 text printer..

Hello, I am unable to control size, style, underline, bold or anything about the font really when printing on sp742.. 
I know the printer is able to print variety of styling but I don't seem to be able to control any of that..
font style or font size does not work. there is nothing in docs that I can find that refer to possible variables..
thanks in advance! 