diff --git a/CHANGELOG.md b/CHANGELOG.md
index 056d4f90..b0d6bdb4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,8 @@ CHANGELOG for FlatCAM beta
 - Fixed the SolderPaste Plugin regarding the special designation 'SP' job type and 'DN' tool shape
 - some fixes in the GCode Editor regarding the new changes in the data structure
 - some updates to the language strings
+- finished preprocessor file for Kosy CNC machine (NCCAD9)
+- fixed the gcode header export to work with the new data structure
 
 15.07.2021
 
diff --git a/appObjects/FlatCAMCNCJob.py b/appObjects/FlatCAMCNCJob.py
index a85d467f..d61cf526 100644
--- a/appObjects/FlatCAMCNCJob.py
+++ b/appObjects/FlatCAMCNCJob.py
@@ -167,7 +167,7 @@ class CNCJobObject(FlatCAMObj, CNCjob):
 
         self.prepend_snippet = ''
         self.append_snippet = ''
-        self.gc_header = self.gcode_header()
+        self.gc_header = ''
         self.gc_start = ''
         self.gc_end = ''
 
@@ -473,7 +473,6 @@ class CNCJobObject(FlatCAMObj, CNCjob):
         # #############################################################################################################
         # ##################################### SIGNALS CONNECTIONS ###################################################
         # #############################################################################################################
-
         self.ui.level.toggled.connect(self.on_level_changed)
 
         # annotation signal
@@ -525,6 +524,8 @@ class CNCJobObject(FlatCAMObj, CNCjob):
         if self.append_snippet != '' or self.prepend_snippet != '':
             preamble = self.prepend_snippet
             postamble = self.append_snippet
+
+        self.gc_header = self.gcode_header()
         gc = self.export_gcode(preamble=preamble, postamble=postamble, to_file=True)
 
         # set the Source File attribute with the calculated GCode
@@ -820,15 +821,17 @@ class CNCJobObject(FlatCAMObj, CNCjob):
         marlin = False
         hpgl = False
         probe_pp = False
+        nccad_pp = False
+
         gcode = ''
 
         start_comment = comment_start_symbol if comment_start_symbol is not None else '('
         stop_comment = comment_stop_symbol if comment_stop_symbol is not None else ')'
 
-        if self.options['type'] == 'geometry':
+        if self.options['type'].lower() == 'geometry':
             try:
                 for key in self.tools:
-                    ppg = self.tools[key]['data']['ppname_g']
+                    ppg = self.tools[key]['data']['tools_mill_ppname_g']
                     if 'marlin' in ppg.lower() or 'repetier' in ppg.lower():
                         marlin = True
                         break
@@ -838,24 +841,33 @@ class CNCJobObject(FlatCAMObj, CNCjob):
                     if "toolchange_probe" in ppg.lower():
                         probe_pp = True
                         break
-            except KeyError:
-                # self.app.log.debug("FlatCAMCNCJob.gcode_header() error: --> %s" % str(e))
+                    if "nccad" in ppg.lower():
+                        nccad_pp = True
+            except Exception as e:
+                self.app.log.debug("FlatCAMCNCJob.gcode_header() error: --> %s" % str(e))
                 pass
 
         try:
-            if 'marlin' in self.options['ppname_e'].lower() or 'repetier' in self.options['ppname_e'].lower():
+            if 'marlin' in self.options['tools_drill_ppname_e'].lower() or \
+                    'repetier' in self.options['tools_drill_ppname_e'].lower():
                 marlin = True
         except KeyError:
             # self.app.log.debug("FlatCAMCNCJob.gcode_header(): --> There is no such self.option: %s" % str(e))
             pass
 
         try:
-            if "toolchange_probe" in self.options['ppname_e'].lower():
+            if "toolchange_probe" in self.options['tools_drill_ppname_e'].lower():
                 probe_pp = True
         except KeyError:
             # self.app.log.debug("FlatCAMCNCJob.gcode_header(): --> There is no such self.option: %s" % str(e))
             pass
 
+        try:
+            if 'nccad' in self.options['tools_drill_ppname_e'].lower():
+                nccad_pp = True
+        except KeyError:
+            pass
+
         if marlin is True:
             gcode += ';Marlin(Repetier) G-CODE GENERATED BY FLATCAM v%s - www.flatcam.org - Version Date:    %s\n' % \
                      (str(self.app.version), str(self.app.version_date)) + '\n'
@@ -889,6 +901,15 @@ class CNCJobObject(FlatCAMObj, CNCjob):
 
             gcode += '(Units: ' + self.units.upper() + ')\n' + "\n"
             gcode += '(Created on ' + time_str + ')\n' + '\n'
+        elif nccad_pp is True:
+            gcode += ';NCCAD9 G-CODE GENERATED BY FLATCAM v%s - www.flatcam.org - Version Date:    %s\n' % \
+                     (str(self.app.version), str(self.app.version_date)) + '\n'
+
+            gcode += ';Name: ' + str(self.options['name']) + '\n'
+            gcode += ';Type: ' + "G-code from " + str(self.options['type']) + '\n'
+
+            gcode += ';Units: ' + self.units.upper() + '\n' + "\n"
+            gcode += ';Created on ' + time_str + '\n' + '\n'
         else:
             gcode += '%sG-CODE GENERATED BY FLATCAM v%s - www.flatcam.org - Version Date: %s%s\n' % \
                      (start_comment, str(self.app.version), str(self.app.version_date), stop_comment) + '\n'
diff --git a/preprocessors/NCCAD9.py b/preprocessors/NCCAD9.py
index 715e7be6..d4e1db2c 100644
--- a/preprocessors/NCCAD9.py
+++ b/preprocessors/NCCAD9.py
@@ -20,7 +20,7 @@ class NCCAD9(PreProc):
         units = ' ' + str(p['units']).lower()
         coords_xy = p['xy_toolchange']
         end_coords_xy = p['xy_end']
-        gcode = ';This preprocessor outputs GCode suitable for the Max Computer GmbH nccad9 Computer Numeric Control.'
+        gcode = ';This preprocessor outputs GCode suitable for the Max Computer GmbH nccad9 Computer Numeric Control.\n'
 
         xmin = '%.*f' % (p.coords_decimals, p['options']['xmin'])
         xmax = '%.*f' % (p.coords_decimals, p['options']['xmax'])
@@ -89,7 +89,7 @@ class NCCAD9(PreProc):
                                                     p.decimals, end_coords_xy[1]) + units + '\n'
         else:
             gcode += ';X,Y End: ' + "None" + units + '\n'
-        gcode += '(Steps per circle: ' + str(p['steps_per_circle']) + ')\n'
+
         gcode += ';Steps per circle: ' + str(p['steps_per_circle']) + '\n'
 
         if str(p['options']['type']) == 'Excellon' or str(p['options']['type']) == 'Excellon Geometry':
@@ -122,6 +122,7 @@ class NCCAD9(PreProc):
     def toolchange_code(self, p):
         z_toolchange = p.z_toolchange
         toolchangexy = p.xy_toolchange
+
         f_plunge = p.f_plunge
 
         if toolchangexy is not None:
@@ -141,16 +142,14 @@ class NCCAD9(PreProc):
         if str(p['options']['type']) == 'Excellon':
             no_drills = p['tools'][int(p['tool'])]['nr_drills']
 
-            if toolchangexy is not None:
+            if toolchangexy is not None and x_toolchange !=0.0 and y_toolchange != 0.0:
                 gcode = """
-M5
-G0 Z{z_toolchange}
-G0 X{x_toolchange} Y{y_toolchange}                
-T{tool}
-M6
-;MSG, Change to Tool Dia = {toolC}, Total drills for tool T{tool} = {t_drills}
-M0
-G0 Z{z_toolchange}
+M10 O6.0 ; Stop spindle
+G00 Z{z_toolchange}
+G00 X{x_toolchange} Y{y_toolchange}                
+M01 Insert tool {tool}
+; Change to Tool Dia = {toolC}, Total drills for tool T{tool} = {t_drills}
+G76 ; Move to reference point to ensure correct coordinates after tool change
 """.format(x_toolchange=self.coordinate_format % (p.coords_decimals, x_toolchange),
            y_toolchange=self.coordinate_format % (p.coords_decimals, y_toolchange),
            z_toolchange=self.coordinate_format % (p.coords_decimals, z_toolchange),
@@ -159,13 +158,12 @@ G0 Z{z_toolchange}
            toolC=toolC_formatted)
             else:
                 gcode = """
-M5
-G0 Z{z_toolchange}
-T{tool}
-M6
-;MSG, Change to Tool Dia = {toolC}, Total drills for tool T{tool} = {t_drills}
-M0
-G0 Z{z_toolchange}
+M10 O6.0 ; Stop spindle
+G00 Z{z_toolchange}
+G77 ; Move to release position
+M01 Insert tool {tool}
+;Change to Tool Dia = {toolC}, Total drills for tool T{tool} = {t_drills}
+G76 ; Move to reference point to ensure correct coordinates after tool change
 """.format(z_toolchange=self.coordinate_format % (p.coords_decimals, z_toolchange),
            tool=int(p.tool),
            t_drills=no_drills,
@@ -176,16 +174,14 @@ G0 Z{z_toolchange}
             return gcode
 
         else:
-            if toolchangexy is not None:
+            if toolchangexy is not None and x_toolchange !=0.0 and y_toolchange != 0.0:
                 gcode = """
-M5
-G0 Z{z_toolchange}
-G0 X{x_toolchange} Y{y_toolchange}
-T{tool}
-M6    
-;MSG, Change to Tool Dia = {toolC}
-M0
-G0 Z{z_toolchange}
+M10 O6.0 ; Stop spindle
+G00 Z{z_toolchange}
+G00 X{x_toolchange} Y{y_toolchange}
+M01 Insert tool {tool}  
+;Change to Tool Dia = {toolC}
+G76 ; Move to reference point to ensure correct coordinates after tool change
 """.format(x_toolchange=self.coordinate_format % (p.coords_decimals, x_toolchange),
            y_toolchange=self.coordinate_format % (p.coords_decimals, y_toolchange),
            z_toolchange=self.coordinate_format % (p.coords_decimals, z_toolchange),
@@ -193,13 +189,12 @@ G0 Z{z_toolchange}
            toolC=toolC_formatted)
             else:
                 gcode = """
-M5
-G0 Z{z_toolchange}
-T{tool}
-M6    
-;MSG, Change to Tool Dia = {toolC}
-M0
-G0 Z{z_toolchange}
+M10 O6.0 ; Stop spindle
+G00 Z{z_toolchange}
+G77 ; Move to release position
+M01 Insert tool {tool}  
+;Change to Tool Dia = {toolC}
+G76 ; Move to reference point to ensure correct coordinates after tool change
 """.format(z_toolchange=self.coordinate_format % (p.coords_decimals, z_toolchange),
            tool=int(p.tool),
            toolC=toolC_formatted)
@@ -222,13 +217,18 @@ G0 Z{z_toolchange}
         return ('G01 ' + self.position_code(p)).format(**p) + " " + self.inline_feedrate_code(p)
 
     def end_code(self, p):
+        gcode = ''
         coords_xy = p['xy_end']
-        gcode = ('G00 Z' + self.feedrate_format % (p.fr_decimals, p.z_end) + " " + self.feedrate_rapid_code(p) + "\n")
 
         if coords_xy and coords_xy != '':
+            gcode = ('G00 Z' + self.feedrate_format % (p.fr_decimals, p.z_end) + " " + self.feedrate_rapid_code(
+                p) + "\n")
             gcode += 'G0 X{x} Y{y}'.format(x=coords_xy[0], y=coords_xy[1]) + " " + self.feedrate_rapid_code(p) + "\n"
 
-        gcode += 'M10 O2.0 ;turn off high speed spindle at relay 2'
+        gcode += '''
+G77 ; Move to release position
+M10 O6.0 ; Stop spindle
+'''
         return gcode
 
     def feedrate_code(self, p):