INT 15 - Compaq Contura 486 and "Alladin" 1993/08/05 ROMs - GET ???
	AX = 4604h
Return: CF clear if successful
	    AL = byte read from I/O port 03F8h
	CF set on error (not supported)
	    AH = 86h (unsupported function)
Note:	also supported by 1993/7/26 LTE Lite 386 ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs.