Format of DR DOS 5.0-6.0 current directory structure entry (array):
Offset	Size	Description	)
 00h 67 BYTEs	ASCIZ pathname of actual root directory for this logical drive
 43h	WORD	drive attributes
		1000h SUBSTed drive
		3000h??? JOINed drive
		4000h physical drive
		5000h ASSIGNed drive
		7000h JOINed drive
		8000h network drive
 45h	BYTE	physical drive number (0=A:) if this logical drive is valid
 46h	BYTE	??? apparently flags for JOIN and ASSIGN
 47h	WORD	cluster number of start of parent directory (0000h = root)
 49h	WORD	entry number of current directory in parent directory
 4Bh	WORD	cluster number of start of current directory
 4Dh	WORD	used for media change detection (details not available)
 4Fh	WORD	cluster number of SUBST/JOIN "root" directory
		0000h if physical root directory
SeeAlso: #01643