INT 21 - DUBLDISK.SYS v2.6 - GET INFO

	AX = 4404h
	BL = drive number of DoubleDisk drive (00h = default, 01h = A:, etc.)
	CX = number of bytes (000Ah-0014h, call ignored otherwise)
	DS:DX -> data record (see #01530)
Return: CF clear if successful
	    AX = number of bytes read
	CF set on error
	    AX = error code (01h,05h,06h,0Dh) (see #01680 at AH=59h/BX=0000h)
Program: DUBLDISK.SYS is the device driver portion of DoubleDisk, a disk
	  expander by Vertisoft Systems, Inc.
InstallCheck:	for v2.6, scan memory for the signature "FAT 2.6  byte:",
	  which is immediately followed by a data table (see #01531)
BUG:	VOPT (a disk optimizer by Golden Bow Software) assumes that any driver
	  which returns the "correct" number of bytes when the first word of
	  the buffer for the data record contains the signature value 4444h is
	  DoubleDisk; a workaround is for the non-DoubleDisk driver to return
	  no data if the signature is present
SeeAlso: AX=440Dh"DOS 3.2+"
Index:	installation check;DUBLDISK.SYS