INT E0 - DR Multiuser DOS - "A_READ" - READ CHARACTER FROM DEFAULT AUX DEVICE
	CL = 03h
Return: AL = ASCII character
	may destroy SI,DI???
Notes:	A_READ reads the next 8-bit character from the logical auxilliary
	  input device (AUXn:); control is not returned to the calling
	  process until a character has been read.
	if another process owns AUX, this call blocks until the device becomes
	  available
	this function is also supported by REAL/32
SeeAlso: INT 21/AH=03h,INT E0/CL=04h,INT E0/CL=07h,INT E0/CL=A5h,INT E0/CL=ACh