DISKTYPE()
 Determines the type of data carrier
------------------------------------------------------------------------------
 Syntax

     DISKTYPE([<cDrive>]) --> nDiskType

 Argument

     <cDrive>  Designates the drive designator (A, B, C, etc.) for which
     you want to determine the data carrier.  The default is the current
     drive.

 Returns

     The returned value corresponds to the FAT-ID byte of a floppy or hard
     disk.  The following codes apply:

     Table 7-8:  FAT-ID Definitions
     ------------------------------------------------------------------------
     FAT-ID  Symb. constants     Definition
     ------------------------------------------------------------------------
     255     DT_DS_SEC_8         Double sided 8 sectors
     254     DT_SS_SEC_8         Single sided 8 sectors
     253     DT_DS_SEC_9         Double sided 9 sectors
     252     DT_SS_SEC_9         Single sided 9 sectors
     249     DT_DS_SEC_15        Double sided 15 sectors (HD-Disk)
     249     DT_35_SEC_9         Double sided 3.5" 9 sectors (ident. to 5.25"
                                 HD)
     240     DT_35_SEC_18        Double sided 3.5" 18 sectors
     248     DT_HARDDISK         Hard disk
     ------------------------------------------------------------------------

 Description

     If a 360K floppy is written on an AT in a 1.2 MB drive, you may not be
     able to read it on other systems, particularly on PC XTs.  This function
     determines how the floppy you are about to use is formatted and provides
     the corresponding warning.

 Example

     Determine if an XT disk is being written to an AT:

     IF ISAT() .AND. DISKTYPE("A") == DT_DS_SEC_9
        ? "Warning!"
        ? "Under certain circumstances this disk not"
        ?? " readable on other systems!"
     ENDIF