INT 15 - EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). SYSTEM ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. - READ FUNCTION CONFIGURATION INFORMATION
	AX = D801h
	CH = function number to read
	CL = slot number (including embedded and virtual)
	DS:SI -> 320-byte buffer for standard configuration data block
Return: CF clear if successful
	    AH = 00h
	    DS:SI buffer filled
	CF set on error
	    AH = error code (80h-83h,86h,87h) (see #00539)
	BX destroyed
Note:	call with AL=81h if using 32-bit CS addressing mode instead of 16-bit
	this function is also supported by the Compaq SystemPro 486, but it
	  uses more than 1297 bytes of stack.
BUG:	some implementations appear to destroy the DF direction flag;
	  the Novell DOS 7+ memory managers explicitly clear it afterwards.