Name:    Flash Calculations
Models:  fx-4000P and above
Size:    26 bytes
Version: 1.0
Author:  Lupus Yonderboy
E-mail:  lupusy@Tesla.rcub.bg.ac.yu
URL:     http://www.rcub.bg.ac.yu/~lupusy/

Description:

   This program will calculate approximate f-stop for the flash.  It uses
   given distance to the object and film ISO rating.


Usage:

   Input:
   
   I  - film  ISO  rating
   d  - distance to the object
   GN - GN  (Guide Number) of the flash you are using


   Output:

   Approximate f-stop.


Examples:

   I?
   100
   d?
   6
                3.67

   So,  you  are  using  ISO  100 film, and your object is 6 meters away.
   Calcullator suggest that you use f:3.6.