INT 2F - DBLSPACE.BIN - "ActivateDrive" - MOUNT COMPRESSED DRIVE
	AX = 4A11h
	BX = 0005h
	DL = drive number (0=A:) to assign to new drive
	ES:SI -> activation record (see #02805)
Return: status returned in activation record (see #02806)
SeeAlso: AX=4A11h/BX=0000h,AX=4A11h/BX=0006h


Format of DBLSPACE activation record:
Offset	Size	Description	(Table 02805)
 00h  2 BYTEs	signature "MD" (4Dh 44h)
 02h	BYTE	4Dh ('M') mount command
 03h	BYTE	error code (set to FFh before calling) (see #02806)
 04h	BYTE	host drive number (0=A:)
 05h	???	DISK_UNIT structure (not documented)


(Table 02806)
Values for DBLSPACE Mount error code:
 00h	successful
 01h	drive letter not available for DoubleSpace
 02h	drive letter already in use
 03h	no more disk units (increase MaxRemovableDrives in .INI)
 09h	CVF too fragmented
SeeAlso: #02805,#02804