Alpha_To_Font
convert an alpha code to a font code point. The specially here is that there are only 128 alpha codes which can be displayed (that is, are not ar00 … ar1f, etc) where a and a+128 being the same code. The first 128 alpha codes match the font codes.
However, there are 256 font codes and those from 128…255 are used for internal special characters.
Return
font character
Parameters
Alpha
alpha character