Interrupt 1Bh  Control-Break
(0:006Ch)       This interrupt is called when the keyboard scanner of the IBM  
		machines detects Ctrl and Break pressed at the same time. 
 
note 1) If the break occurred while processing an interrupt, one or more 
	end of interrupt commands must be send to the 8259 Programmable 
	Interrupt Controller. 
     2) All I/O devices should be reset in case an operation was underway at 
	the time. 
     3) It is normally pointed to an IRET during system initialization so that 
	it does nothing, but some programs change it to return a ctrl-C scan  
        code and thus invoke Int\23.