Function 14h Load LCD Character Font (Convertible)
entry AH 14h
AL 00h load user specified font
BH number of bytes per character
BL 00h load main font (block 0)
01h load alternate font (block 1)
CX number of characters to store
DX character offset into RAM font area
ES:DI pointer to character font
AL 01h load system ROM default font
BL 00h load main font (block 0)
01h load alternate font (block 1)
AL 02h set mapping of LCD high intensity attribute
BL 00h ignore high intensity attribute
01h map high intensity to underscore
02h map high intensity to reverse video
03h map high intensity to seleected alternate font
return unknown