diff --git a/src/demo_client.rb b/src/demo_client.rb
index e04e302..7ece6ea 100755
--- a/src/demo_client.rb
+++ b/src/demo_client.rb
@@ -69,6 +69,7 @@ VERBOSE = 0
 
 include APDU
 
+# tell APDU methods how to send
 def transmit_apdu(apdu)
   return @client.apdu(apdu)
 end
diff --git a/src/demo_server.rb b/src/demo_server.rb
new file mode 100755
index 0000000..414c5d3
--- /dev/null
+++ b/src/demo_server.rb
@@ -0,0 +1,60 @@
+#!/usr/bin/env ruby
+=begin
+This file is part of SAP.
+
+SAP is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+SAP is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with SAP.  If not, see <http://www.gnu.org/licenses/>.
+
+Copyright (C) 2011 Kevin "tsaitgaist" Redon kevredon@mail.tsaitgaist.info
+=end
+# this program is there to start a server
+require 'socket'
+require 'pcsc_server'
+require 'sim_server'
+
+# the io the server should use (:tcp, :unix)
+io_type = :tcp
+# the server to use (:pcsc, :sim)
+server_type = :pcsc
+
+# create the IO
+case io_type
+when :tcp
+  TCP_HOST = "localhost"
+  TCP_PORT = "1337"
+  socket = TCPServer.new(TCP_HOST,TCP_PORT)
+when :unix
+  UNIX = "/tmp/sap_server.socket"
+  socket = UNIXServer.new(APDU_SOCKET)
+else
+  raise "unkown IO type"
+end
+
+# wait for a client to connect
+io = socket.accept
+
+case server_type
+when :pcsc
+  server = PCSCServer.new(io)
+when :sim
+  server = SIMServer.new(io)
+else
+  raise "unkown server type"
+end
+
+# starting the server
+server.start
+
+# close IO when finished
+io.close
+server.close
diff --git a/src/pcsc_server.rb b/src/pcsc_server.rb
old mode 100755
new mode 100644
index a06c1e7..a57d3f7
--- a/src/pcsc_server.rb
+++ b/src/pcsc_server.rb
@@ -18,7 +18,6 @@ along with SAP.  If not, see <http://www.gnu.org/licenses/>.
 Copyright (C) 2011 Kevin "tsaitgaist" Redon kevredon@mail.tsaitgaist.info
 =end
 require 'lib/server'
-require 'socket'
 require 'rubygems'
 require 'smartcard'
 =begin
@@ -109,9 +108,3 @@ class PCSCServer < Server
   end
 
 end
-
-# demo application, using TCP socket
-socket = TCPServer.new("localhost",1337)
-io = socket.accept
-server = PCSCServer.new(io)
-server.start
diff --git a/src/sim_server.rb b/src/sim_server.rb
old mode 100755
new mode 100644
index b6873dc..58f016a
--- a/src/sim_server.rb
+++ b/src/sim_server.rb
@@ -140,7 +140,7 @@ class SIMServer < Server
   # select file using the file ID
   # node representing the file is returned
   # nil is return if file does not exist or is unaccessible
-  def select (id)
+  def select(id)
     response = nil
     # get the current directory
     dfs = [0x3f,0x5f,0x7f]
@@ -179,9 +179,3 @@ class SIMServer < Server
   end
 
 end
-
-# demo application, using TCP socket
-socket = TCPServer.new("localhost",1337)
-io = socket.accept
-server = SIMServer.new(io)
-server.start