Interrupt 1Fh  Pointer to Graphics Character Extensions (Graphics Set 2)
(0:007Ch)	This is the pointer to data used by the ROM video routines to
		display characters above ASCII 127 while in CGA medium and high 
                resolution graphics modes.
 
note 1) Doubleword address points to 1K table composed of 28 8-byte character  
	definition bit-patterns. First byte of each entry is top row, last byte 
	is bottom row. 
     2) The first 128 character patterns are located in system ROM. 
     3) This vector is set to 000:0 at system initialization 
     4) Used by DOS' external GRAFTABL command