INT 49 - TI Professional PCIBM PC - CRT - SCROLL UP/COPY WINDOW
	AH = 06h
	AL = source blanking
	    00h blank source region (move/scroll)
	    nonzero do not blank source region (copy)
	DH,DL = source start column,row
	BH,BL = destination start column,row
	CH = width of region to move/copy
	CL = height of region to move/copy
Return: nothing
Notes:	AH=00h,04h,05h,0Bh,0Ch,0Dh,0Fh are documented as NOPs
	the specified region may be wider than the screen, but reliable
	  operation then requires that the height be exactly one row
SeeAlso: AH=01h,AH=02h,AH=07h,AH=13h,AH=14h