diff --git a/hardware/Rakefile b/hardware/Rakefile
index 79744e7..5e00e7c 100644
--- a/hardware/Rakefile
+++ b/hardware/Rakefile
@@ -43,26 +43,28 @@ task :default => [:version,:print,:notes,:photo,:gerber]
 desc "create release file"
 release = "hardware-release_v#{version}.tar.gz"
 task :release => release
-CLOBBER.include(release) if File.exist? release
+CLOBBER.include(release)
 
 desc "set version in schematic and layout"
-task :version => targets.collect{|target| [target[:vsch],target[:vpcb]]}.flatten
+versions = targets.collect{|target| [target[:vsch],target[:vpcb]]}.flatten
+task :version => versions
+CLEAN.include(versions)
 targets.each do |target|
-  CLEAN.include(target[:vsch]) if File.exist? target[:vsch]
-  CLEAN.include(target[:vpcb]) if File.exist? target[:vpcb]
-  CLOBBER.include("#{target[:name]}_*.sch") if File.exist? "#{target[:name]}_*.sch"
-  CLOBBER.include("#{target[:name]}_*.pcb")) if File.exist? "#{target[:name]}_*.pcb"
+  CLOBBER.include("#{target[:name]}_*.sch")
+  CLOBBER.include("#{target[:name]}_*.pcb")
 end
-=begin
+
 desc "print schematic and layout (as pdf)"
-task :print => ["#{target}_schematic.pdf","#{target}_layout.pdf"]
-CLEAN.include("#{target}_schematic.pdf")
-CLEAN.include("#{target}_layout.pdf")
+prints = targets.collect{|target| ["#{target[:name]}_schematic.pdf","#{target[:name]}_layout.pdf"]}.flatten
+task :print => prints
+CLEAN.include(prints)
 
 desc "export notes from schematic"
-task :notes => "notes.txt"
-CLOBBER.include("notes.txt")
+notes = targets.collect{|target| "#{target[:name]}_notes.txt"}
+task :notes => notes
+CLEAN.include(notes)
 
+=begin
 desc "verify schematic attributes"
 task :verify => vsch do |t|
   ["value","footprint"].each do |attribute|
@@ -85,20 +87,23 @@ desc "convert schematic to pcb layout"
 task :sch2pcb => vsch do |t|
   sh "gsch2pcb #{t.prerequisites[0]} --elements-dir #{File.dirname(__FILE__)}/lib/footprints --skip-m4 --output-name #{target}"
 end
+=end
 
-PHOTOS = ["#{target}_layout-top.png","#{target}_layout-bottom.png"]
+photos = targets.collect{|target| ["#{target[:name]}_layout-top.png","#{target[:name]}_layout-bottom.png"]}.flatten
 desc "render layout"
-task :photo => PHOTOS
-CLOBBER.include(PHOTOS)
+task :photo => photos
+CLOBBER.include(photos)
 
-GERBERS = [".top.gbr",".topmask.gbr",".toppaste.gbr",".topsilk.gbr",".bottom.gbr",".bottommask.gbr",".bottompaste.gbr",".bottomsilk.gbr",".outline.gbr",".fab.gbr",".plated-drill.cnc",".unplated-drill.cnc"].collect{|suffix| target+suffix}
 desc "export gerber"
-task :gerber => GERBERS
-CLOBBER.include(GERBERS)
+GERBERS = [".top.gbr",".topmask.gbr",".toppaste.gbr",".topsilk.gbr",".bottom.gbr",".bottommask.gbr",".bottompaste.gbr",".bottomsilk.gbr",".outline.gbr",".fab.gbr",".plated-drill.cnc",".unplated-drill.cnc"]
+gerbers = targets.collect{|target| GERBERS.collect{|suffix| target[:name]+suffix}}.flatten
+task :gerber => gerbers
+CLOBBER.include(gerbers)
 
 desc "reformat gerber and drill output (some programs like LPKF CircuitPro have difficulties with gEDA pcb output)"
-task :reformat => GERBERS do
-  GERBERS.each do |gerber|
+task :reformat => gerbers do
+  gerbers.each do |gerber|
+    next unless File.exist? gerber
     if gerber.end_with? ".gbr" then
       sh "gerbv --export=rs274x --output=#{gerber} #{gerber}"
     elsif gerber.end_with? ".cnc" then
@@ -106,7 +111,6 @@ task :reformat => GERBERS do
     end
   end
 end
-=end
 
 # ================
 # helper functions
@@ -147,7 +151,7 @@ def bom2(schematic, attributes)
   end
   return to_return
 end
-CLEAN.include("attribs") if File.exist? "attribs"
+CLEAN.include("attribs")
 
 # ===============
 # file generation
@@ -163,7 +167,7 @@ targets.each do |target|
     # the date
     sh "sed -i 's/\\(date=\\)\\$Date\\$/\\1#{date}/' #{t.name}"
     # the revision
-    sh "sed -i 's/\\(revision=\\)\\$Revision\\$/\\1#{targert[:sch_rev]}/' #{t.name}"
+    sh "sed -i 's/\\(revision=\\)\\$Revision\\$/\\1#{target[:sch_rev]}/' #{t.name}"
   end
 end
 
@@ -183,53 +187,61 @@ targets.each do |target|
     end
   end
 end
-=begin
+
 desc "generate printable version (PDF) of schematic"
-file "#{target}_schematic.pdf" => vsch do |t|
-  sh "gaf export -f pdf -c -o #{t.name} #{t.prerequisites.join(' ')} 2> /dev/null"
+targets.each do |target|
+  file "#{target[:name]}_schematic.pdf" => target[:vsch] do |t|
+    sh "gaf export -f pdf -c -o #{t.name} #{t.prerequisites.join(' ')} 2> /dev/null"
+  end
 end
 
 desc "generate printable documentation (PDF) from layout"
-file "#{target}_layout.pdf" => vpcb do |t|
-  sh "pcb -x ps --psfile #{t.name}.ps #{t.prerequisites.join(' ')} 2> /dev/null"
-  sh "ps2pdf #{t.name}.ps #{t.name} 2> /dev/null"
-  sh "rm #{t.name}.ps 2> /dev/null"
+targets.each do |target|
+  file "#{target[:name]}_layout.pdf" => target[:vpcb] do |t|
+    sh "pcb -x ps --psfile #{t.name}.ps #{t.prerequisites.join(' ')} 2> /dev/null"
+    sh "ps2pdf #{t.name}.ps #{t.name} 2> /dev/null"
+    sh "rm #{t.name}.ps 2> /dev/null"
+  end
 end
 
 desc "generate note file from schematic, listing the 'note' attributes from elements"
-file "notes.txt" => vsch do |t|
-  notes_data = bom2(t.prerequisites[0],"note")
-  File.open(t.name,"w") do |notes_file|
-    notes_data.each do |note|
-      next if note["note"]=="unknown"
-      notes_file.puts "#{note[:refdes]*','}:\n#{note["note"]}\n\n"
+targets.each do |target|
+  file "#{target[:name]}_notes.txt" => target[:vsch] do |t|
+    notes_data = bom2(t.prerequisites[0],"note")
+    File.open(t.name,"w") do |notes_file|
+      notes_data.each do |note|
+        next if note["note"]=="unknown"
+        notes_file.puts "#{note[:refdes]*','}:\n#{note["note"]}\n\n"
+      end
     end
   end
 end
 
 desc "generate photo realistic picture from layout (front side)"
-file "#{target}_layout-top.png" => vpcb do |t|
-#  sh "pcb -x png --dpi 600 --format PNG --photo-mode --outfile #{target}_layout-top.png #{t.prerequisites.join(' ')}"
-  sh "pcb -x png --format PNG --photo-mode --outfile #{target}_layout-top.png #{t.prerequisites.join(' ')}"
-end
-
-desc "generate photo realistic picture from layout (bottom side)"
-file "#{target}_layout-bottom.png" => vpcb do |t|
-#  sh "pcb -x png --dpi 600 --format PNG --photo-mode --photo-flip-x --outfile #{target}_layout-bottom.png #{t.prerequisites.join(' ')}"
-  sh "pcb -x png --format PNG --photo-mode --photo-flip-x --outfile #{target}_layout-bottom.png #{t.prerequisites.join(' ')}"
-end
-
-desc "export gerber (and drill) files from layout"
-GERBERS.each do |gerber|
-  file gerber => vpcb do |t|
-    puts "make #{t.name}"
-    sh "pcb -x gerber --gerberfile #{target} --all-layers #{t.prerequisites.join(' ')}"
+targets.each do |target|
+  file "#{target[:name]}_layout-top.png" => target[:vpcb] do |t|
+    sh "pcb -x png --dpi 600 --format PNG --photo-mode --outfile #{t.name} #{t.prerequisites.join(' ')}"
+  end
+end
+
+desc "generate photo realistic picture from layout (bottom side)"
+targets.each do |target|
+  file "#{target[:name]}_layout-bottom.png" => target[:vpcb] do |t|
+    sh "pcb -x png --dpi 600 --format PNG --photo-mode --photo-flip-x --outfile #{t.name} #{t.prerequisites.join(' ')}"
+  end
+end
+
+desc "export gerber (and drill) files from layout"
+targets.each do |target|
+  GERBERS.each do |suffix|
+    file target[:name]+suffix => target[:vpcb] do |t|
+      sh "pcb -x gerber --gerberfile #{target[:name]} --all-layers #{t.prerequisites.join(' ')}"
+    end
   end
 end
 
-ATTACHMENTS = ["cern_ohl_v_1_2_howto.pdf","CHANGES.txt","LICENSE.txt","PRODUCT.txt"]
 desc "create archive with release files"
-file "hardware-release_v#{version}.tar.gz" => ATTACHMENTS+["lib",vsch,vpcb,"notes.txt","#{target}_schematic.pdf","#{target}_layout.pdf","#{target}_layout-top.png","#{target}_layout-bottom.png"]+GERBERS do |t|
+ATTACHMENTS = ["cern_ohl_v_1_2_howto.pdf","CHANGES.txt","LICENSE.txt","PRODUCT.txt"]
+file release => prints+notes+photos+gerbers+ATTACHMENTS do |t|
   sh "tar -acf '#{t.name}' #{t.prerequisites.join(' ')}"
 end
-=end
diff --git a/hardware/cern_ohl_v_1_2_howto.pdf b/hardware/cern_ohl_v_1_2_howto.pdf
new file mode 100644
index 0000000..feec817
Binary files /dev/null and b/hardware/cern_ohl_v_1_2_howto.pdf differ