# File lib/image_formats/JvcDsk.rb, line 21
def initialize(file_bytes)
  @file_bytes=file_bytes
  @sectors_per_track = 18
  @side_count = 1
  @sectors_size_code = 1
  @first_sector_id = 1

  @header_size = file_bytes.length % 256
  
  if @header_size == 0 then
  elsif @header_size == 1 then
        @sectors_per_track = file_bytes.unpack("C")
  elsif @header_size == 2 then
        @sectors_per_track, @side_count= file_bytes.unpack("CC")
  elsif @header_size == 3 then
        @sectors_per_track, @side_count, @sectors_size_code = file_bytes.unpack("CCC")
  elsif @header_size == 4 then
        @sectors_per_track, @side_count, @sectors_size_code, @first_sector_id = file_bytes.unpack("CCCC")
  else
  end

        @sector_length = 128 << @sectors_size_code
        @track_count = (file_bytes.length - @header_size) / (@sectors_per_track * @sector_length) / @side_count 
end