[Coco] DECB directory question

[Mike Rowen]

I need help trying to understand the disk directory structure on track  
17 and well the FAT structure. Just a SS 35 track disk.

  For a file entry, byte 13 contains the number of the first granule  
of the file. Is this number an index pointing to a specific byte in  
the FAT? I know that the FAT contains one byte per granule. So, for  
example let's say byte 13 for a given file entry is 06. Does this  
point to byte 06 in the FAT?

Thanks,
-Mike