INT 10 - VIDEO - TANDY 2000 only - SCROLL LEFT PART OR ALL OF SCREEN

	AH = 73h
	AL = number of columns to shift scroll area, 00h to clear entire area
	BH = new attributes for blanked columns at right
	CH,CL = row, column of upper left corner of scroll area
	DH,DL = row, column of lower right corner of scroll area
Return: nothing
SeeAlso: AH=06h,AH=07h,AH=72h"TANDY",INT 15/AH=12h/BH=05h