diff --git a/xtmfile/header.rb b/xtmfile/header.rb
index 35b1825..7e7c2a8 100644
--- a/xtmfile/header.rb
+++ b/xtmfile/header.rb
@@ -3,6 +3,7 @@ require 'rubygems'
 gem 'bindata', '~> 1.2.1'
 require 'bindata'
 
+# FIXME: set default values for header fields
 module XtmFile
 
 	#
diff --git a/xtmfile/splitter.rb b/xtmfile/splitter.rb
index 9030105..f4aab9f 100644
--- a/xtmfile/splitter.rb
+++ b/xtmfile/splitter.rb
@@ -1,19 +1,30 @@
+
+require 'xtmfile/header'
+
 module XtmFile
-class Splitter
-attr_reader :parts, :parts_size
-def initialize input_filename
-@input_filename = input_filename
-@parts = 0
-@parts_size = 0
-end
+	class Splitter
+		attr_reader :parts_size
+		def initialize input_filename
+			@input_filename = input_filename
 
-def parts= count
-end
+			# create and initialize header
+			@header = Header.new
+			@header.filename_str = @input_filename
+		end
 
-def parts_size= size
-end
+		def parts= count
+			@header.filecount = count
+			@parts_size = @header.filesize / count
+		end
 
-def start
-end
-end
+		def parts_size= size
+			count = @header.filesize / size
+			remain = @header.filesize % size
+			count += 1 if remain > 0
+			@header.filecount = count
+		end
+
+		def start
+		end
+	end
 end