INT 1A,0 - Read System Clock Counter

	AH = 00

	on return:
	AL = midnight flag, 1 if 24 hours passed since reset
	CX = high order word of tick count
	DX = low order word of tick count

	- incremented approximately 18.206 times per second
	- at midnight CX:DX is zero
	- this function can be called in a program to assure the date is
	  updated after midnight;  this will avoid the passing two midnights
	  date problem