diff --git a/midi-music-box.cabal b/midi-music-box.cabal
--- a/midi-music-box.cabal
+++ b/midi-music-box.cabal
@@ -1,9 +1,50 @@
 Name:                midi-music-box
-Version:             0.0
+Version:             0.0.0.1
 Synopsis:            Convert MIDI file to music box punch tape
 Description:
   Convert MIDI file to music box punch tape for this kind of music box:
   <http://www.amazon.de/Spieluhr-Lochstreifen/dp/B001WNZOVO/>
+  .
+  Run it like so:
+  .
+  > midi-music-box --output=song.ps song.mid
+  .
+  @song.mid@ is the input file that must be a MIDI file.
+  @song.ps@ is the output file, a PostScript file.
+  You can print it with a printer or to a PDF document
+  or convert it to many other formats.
+  Currently, the output file must always have the @.ps@ filename extension.
+  Other formats could be supported by adding more of the @diagrams-*@ packages.
+  However, this means you have to alter the program.
+  .
+  The program will print the following symbols to the stripe:
+  .
+  * blue dot - correct note that should be punched
+  .
+  * # - this is a semitone and cannot be played accurately
+    (at least on the type of music box I refered to, above)
+  .
+  * ! - the note is outside the range
+  .
+  In case of notes outside the stripe you have to adapt the offset.
+  You may write
+  .
+  > midi-music-box --zerokey=72 --output=song.ps song.mid
+  .
+  in order to make the MIDI note with number 72
+  the left-most note on the stripe.
+  Default is @--zerokey=60@.
+  The number of notes in an octave is 12.
+  If you use a zerokey that is a multiple of 12
+  then white (piano) keys remain white, and black keys remain black,
+  so to speak.
+  If zerokey is not a multiple of 12
+  then white keys may become black an vice versa.
+  Since the music box type considered here only supports white keys,
+  I recommend the following:
+  If the song is in key X major then lookup the MIDI note number for X
+  and choose X plus or minus a multiple of 12 as zerokey.
+  If the song has key Y minor, then X=Y+3.
 Homepage:            http://hub.darcs.net/thielema/midi-music-box
 License:             BSD3
 License-File:        LICENSE
@@ -14,7 +55,7 @@
 Cabal-Version:       >=1.10
 
 Source-Repository this
-  Tag:         0.0
+  Tag:         0.0.0.1
   Type:        darcs
   Location:    http://hub.darcs.net/thielema/midi-music-box
 
@@ -32,8 +73,8 @@
     diagrams-lib >=1.3 && <1.4,
     midi >=0.2.1 && <0.3,
     event-list >=0.1.1 && <0.2,
-    optparse-applicative >=0.11 && <0.12,
+    optparse-applicative >=0.11 && <0.13,
     containers >=0.4 && <0.6,
-    non-empty >=0.1.3 && <0.3,
+    non-empty >=0.1.3 && <0.4,
     utility-ht >=0.0.10 && <0.1,
     base >=4.5 && <4.9