INT 21 - Software Carousel - SELECTIVELY ENABLE/DISABLE MENU AND SWITCHING      
	AX = DF08h
	BL = new state of keyboard (00h disabled, 01h enabled)
Return: AL = status
	    00h Carousel not running
	    01h successful
Program: Software Carousel is a task switcher by SoftLogic Solutions, Inc.
Note:	when the keyboard is is disabled, the user may neither access the
	  Carousel menu nor switch to another memory section