DISKSPEED()
 Determines a comparison value for the drive speed
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 Syntax

     DISKSPEED(<cDrive>) --> nDriveSpeed

 Argument

     <cDrive>  Designates for which physical drive identifier (A, B, C,
     etc.) to determine the speed.  You do not need to use the colon (:).

 Returns

     DISKSPEED() returns a percentage comparison value to a floppy drive of a
     4.77 MHz PC, which corresponds to 100%.

 Description

     Use this function when you want to calculate the approximate duration of
     such complex file operations as INDEX or SORT.  Since the total duration
     always depends upon the remaining computer speed, you should also use
     the SPEED() function..

     If the designated drive is unavailable or cannot be checked (network
     drive), the function returns a 0 value.

 Note

     .  You can only implement DISKSPEED() for physical drives, not
        network drives.

 Examples

     .  Show the speed of drive A:

        ? DISKSPEED("A")            // depends on drive

     .  Show the factor for your hard disk:

        ? DISKSPEED("C")            // e.g. 720  Factor 7.2