INT 21 U - SUPERSTOR - IOCTL - INSTALL CHECK                                    
	AX = 4405h
	BL = drive number (00h = default, 01h = A:, etc)
	(BH = 0???)
	CX = 000Ch (size of SuperStor packet structure)
	DS:DX -> SuperStor packet structure (see #04114)
Return: CF clear if IOCTL successful -- check SuperStor packet for actual
	      status
	    AX = number of bytes actually transferred???
	CF set on error
	    AX = error code (01h,05h,06h,0Dh) (see #01680 at AH=59h/BX=0000h)
Note:	This function is called with CX = 0008h for command 06h by NWCACHE
	  although the Request Packet can be larger.  WINSWAP.SYS calls it
	  with 000Ch - also for command 06h.


Format of SuperStor packet:
Offset	Size	Description	(Table 04114)
 00h	WORD	(call) product signature AA55h
		(ret) result code, 0000h if successful
 02h	BYTE	(call) SuperStor product ID (01h)
 03h	BYTE	(call) SuperStor command parameter:
		06h = get compressed drive structure / drive parameters
		07h = return the compressed length of a file
		08h = return real drive ID for swapped drive
		09h = validate the contents of the cluster
		0Bh = checks whether deleted cluster is free
		0Ch = reallocate previously deleted cluster
		0Dh = read absolute sector from the drive
		0Eh = write absolute sector to the drive
		0Fh = instruct the driver to rebuild tables
		10h = flush any cached Replacement Block Table (RBT) sectors
		      to the drive
---command 06h---
 04h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	(ret) pointer to SuperStor CVF's compressed unit structure
		      (see #04115)
 08h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	(ret) pointer to internal status structure
---command 07h---
 04h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	(ret) size of file in bytes
 08h	WORD	(ret) first cluster number
---command 08h---
 04h	BYTE	(ret) swapped drive (0-based)
---commands 09h,0Bh,0Ch---
 04h	WORD	(call) cluster
---commands 0Dh,0Eh---
 04h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	(call) first logical sector to transfer
 08h	WORD	(call) number of logical sectors to transfer
 0Ah	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	(call) pointer to buffer
---command 0Fh---
 04h	WORD	(call) temporary buffer area
---command 10h---
 no additional parameters


Format of SuperStor CVF compressed unit structure:
Offset	Size	Description	(Table 04115)
 00h 31 BYTEs	BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. parameter block for compressed drive (see #01663)
 1Fh  5 BYTEs	reserved for future expansion of the BPBsee BIOS Parameter Block
 24h 33 BYTEs   DOS 4-6 style drive parameter block for compressed drive
		  (see #01395)
 45h  2 BYTEs	reserved for future expansion of the DPBsee Drive Paramter Block
 47h	WORD	first sector of relocation table (RBT)
 49h	WORD	first sector of file allocation table
 4Bh	WORD	first sector of the data area
 4Dh	BYTE	sec2byteshift
 4Eh  2 BYTEs	???
		Note:	Reportedly these two bytes did not exist in ADDSTOR's
			  specification, so the whole structure would have
			  been documented differently.
 50h	WORD	sectors per cluster
 52h	BYTE	sector shift
 53h	WORD	compression ratio
 55h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	number of physical sectors in the host file
 59h	WORD	OS version
 5Bh	BYTE	SuperStor level
 5Ch	BYTE	unknown???
 5Dh	BYTE	flags
		bits 7-1: ???
		bit 0: drive is mounted
 5Eh	BYTE	unknown???
 5Fh	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	pointer to CVF's underlaying host DCB
		this should be the physical DPBsee Drive Paramter Block for this unit
		    ->  +00h BYTE host unit DOS unit number
		        +01h BYTE CVF's driver host subunit number
Note:	As this SuperStor compressed unit structure's structure is located
	  within the segment the SuperStor driver has occupied, the segment
	  value of its address can be used as an installation check, since it
	  contains the signature "ADDSTOR" at offset 20h in the SuperStor
	  driver.  This is used by Novell DOS 7 WINSWAP.SYS to check for the
	  presence of SuperStor.
SeeAlso: #04114
Index:	installation check;SuperStor