INT 21 - DOS 1+ - GET ALLOCATION INFORMATION FOR DEFAULT DRIVE                  
	AH = 1Bh
Return: AL = sectors per cluster (allocation unit)
	CX = bytes per sector
	DX = total number of clusters
	DS:BX -> media ID byte (see #01356)
Notes:	under DOS 1.x, DS:BX points at an actual copy of the FATsee File Allocation Table; later
	  versions return a pointer to a copy of the FATsee File Allocation Table's ID byte
	this function may not be properly supported on CD-ROMs and other
	  installable file systems (use AX=4402h"CD-ROM" for CD-ROMs
	  instead)
BUG:	DOS 7.10 (Win95B/Win98) reportedly returns incorrect values in AL and
	  DX for FAT12/FAT16 drives, even though it manages correct results
	  for FAT32 drives (DOS windows are not affected, only real-mode
	  DOS)
SeeAlso: AH=1Ch,AH=36h


(Table 01356)
Values for media ID byte:
 FFh	floppy, double-sided, 8 sectors per track (320K)
 FEh	floppy, single-sided, 8 sectors per track (160K)
 FDh	floppy, double-sided, 9 sectors per track (360K)
 FCh	floppy, single-sided, 9 sectors per track (180K)
 FAh	HP 200LX D: ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. disk, 16 sectors per track (995K)
	HP 200LX E: (Stacker host drive ???)
 F9h	floppy, double-sided, 15 sectors per track (1.2M)
	floppy, double-sided, 9 sectors per track (720K,3.5")
 F8h	hard disk
 F0h	other media
	(e.g. floppy, double-sized, 18 sectors per track -- 1.44M,3.5")