MEM F000h:FFE0h - COMPAQ 386 MACHINES                                           
Size: 16 BYTEs
SeeAlso: MEM 80C00000h


Format of Compaq 386 Memory Configuration Data:
Offset	Size	Description	(Table M0134)
 00h	WORD	Compaq 32-bit extra built-in memory available (FFFFh if not)
 02h	WORD	Total size of Compaq extra memory
 04h	WORD	Count of available paragraphs of Compaq extra memory
 06h	WORD	ParagraphA 16-byte unit of memory.  This size is the result of the 8086's segmentation model, where incrementing the segment by one advances the absolute location by 16 bytes. address of last paragraph in use as Compaq extra
		  memory
 08h  2 BYTEs	product class signature "03"
 0Ah  6 BYTEs	signature "03COMPAQ"
Notes:	The full "03COMPAQ" signature can be found in (at least) Compaq 386
	  machines which have dual harddisk controller. (see also CMOS(Complementary Metal-Oxide-Semiconductor) A type of integrated circuit design known for its low power consumption. 70h)
	However, the 6-byte "COMPAQ" signature also seems to be available
	  in other Compaq machines with dual hard disk controllers, at least
	  the MS-DOS/PCIBM PC DOS IO.SYS/IBMBIO.COM checks for if before it calls
	  INT 15/AX=E400h and INT 15/AX=E480h.
	Compaq's extra memory is mappable memory starting at FE00h:0000h
	  growing downwards. It can be made available for example with
	  Novell DOS 7+ EMM386.EXE /COMPAQ=ON.
	Although this structure resides at a ROM-address it is actually write-
	  protected RAM(Random Access Memory)	See also DRAM, SRAM.. To write to the structure to map in Compaq extra
	  memory the write-protection must be temporarily disabled by setting
	  bit 1 at WORD 80C00000h.