INT 5F - HP 100LX/200LX GRAPHICS PRIMITIVES - GET FONT POINTER                  
	AH = 10h
	CX = font size of desired font
	    0808h  8x8	small  (80x25 text)
	    0A0Bh 11x10 medium (64x18 text)
	    100Ch 12x16 large  (40x16 text)
Return: DX:AX -> ptr to font or 0000h:fontID# if built-in font
SeeAlso: AH=11h