INT 4D - TI Professional PC - DISK - GET STATUS OF LAST OPERATION

	AH = 01h
	DL = drive (bit 7 set for hard disk)
Return: CF clear if status unchanged
	CF set if status changed since last call
	AH = 00h
	AL = status of previous operation (see #00234 at INT 13/AH=01h)
Notes:	this function is nearly the same as INT 13/AH=01h on a standard PC BIOS
	the TI's BIOS tranparently performs a number of retries, and an error
	  status is only reported if all of the retries fail.  To get the error
	  status if the operation succeeded on a retry, use AH=07h instead
SeeAlso: AH=00h,AH=07h,INT 13/AH=01h