diff --git a/GCodes.h b/GCodes.h
index b0c0d05..56ff118 100644
--- a/GCodes.h
+++ b/GCodes.h
@@ -33,6 +33,7 @@ class GCodeBuffer
     boolean Seen(char c);
     float GetFValue();
     int GetIValue();
+    long GetLValue();
     char* Buffer();
     
   private:
@@ -58,14 +59,18 @@ class GCodes
     
   private:
   
-    void ActOnGcode(GCodeBuffer* gb);
+    boolean ActOnGcode(GCodeBuffer* gb);
     void SetUpMove(GCodeBuffer* gb);
+    boolean doDwell(GCodeBuffer *gb);
     Platform* platform;
     boolean active;
     Webserver* webserver;
-    unsigned long lastTime;
+    unsigned long dwellTime;
+    boolean dwellWaiting;
     GCodeBuffer* webGCode;
     GCodeBuffer* fileGCode;
+    boolean webGCodePending;
+    boolean fileGCodePending;
     boolean moveAvailable;
     boolean heatAvailable;
     float moveBuffer[DRIVES+1]; // Last is feedrate
@@ -74,6 +79,8 @@ class GCodes
     char gCodeLetters[DRIVES + 1]; // Extra is for F
     float lastPos[DRIVES - AXES]; // Just needed for relative moves.
     float distanceScale;
+    int fileBeingPrinted;
+    int fileToPrint;
 };
 
 #endif
diff --git a/GCodes.ino b/GCodes.ino
index 0da10c5..0efbc70 100644
--- a/GCodes.ino
+++ b/GCodes.ino
@@ -37,9 +37,10 @@ void GCodes::Exit()
 
 void GCodes::Init()
 {
-  lastTime = platform->Time();
   webGCode->Init();
   fileGCode->Init();
+  webGCodePending = false;
+  fileGCodePending = false;
   active = true;
   moveAvailable = false;
   heatAvailable = false;
@@ -49,6 +50,49 @@ void GCodes::Init()
   distanceScale = 1.0;
   for(char i = 0; i < DRIVES - AXES; i++)
     lastPos[i] = 0.0;
+  fileBeingPrinted = -1;
+  fileToPrint = -1;
+  dwellWaiting = false;
+  dwellTime = platform->Time();
+}
+
+void GCodes::Spin()
+{
+  if(!active)
+    return;
+    
+  if(webGCodePending)
+  {
+    webGCodePending = !ActOnGcode(webGCode);
+    return;
+  }
+
+  if(fileGCodePending)
+  {
+    fileGCodePending = !ActOnGcode(fileGCode);
+    return;
+  }  
+    
+  if(webserver->GCodeAvailable())
+  {
+    if(webGCode->Put(webserver->ReadGCode()))
+      webGCodePending = !ActOnGcode(webGCode);
+    return;
+  }
+  
+  if(fileBeingPrinted >= 0)
+  {
+     unsigned char b;
+     if(platform->Read(fileBeingPrinted, b))
+     {
+       if(fileGCode->Put(b))
+         fileGCodePending = !ActOnGcode(fileGCode);
+     } else
+     {
+        platform->Close(fileBeingPrinted);
+        fileBeingPrinted = -1;
+     }
+  }
 }
 
 // Move expects all axis movements to be absolute, and all
@@ -101,12 +145,51 @@ void GCodes::SetUpMove(GCodeBuffer *gb)
 
 void GCodes::QueueFileToPrint(char* fileName)
 {
-  platform->Message(HOST_MESSAGE, "File queued for printing.\n");
+  fileToPrint = platform->OpenFile(platform->GetGCodeDir(), fileName, false);
 }
 
-void GCodes::ActOnGcode(GCodeBuffer *gb)
+
+// Function to handle dwell delays.  Return true for
+// Dwell finished, false otherwise.
+
+boolean GCodes::doDwell(GCodeBuffer *gb)
+{
+  unsigned long dwell;
+  
+  if(gb->Seen('P'))
+    dwell = 1000ul*(unsigned long)gb->GetLValue(); // P values are in milliseconds; we need microseconds
+  else
+    return true;  // No time given - throw it away
+      
+  // Wait for all the queued moves to stop
+      
+  if(!reprap.GetMove()->AllMovesFinished())
+    return false;
+      
+  // Are we already in a dwell?
+      
+  if(dwellWaiting)
+  {
+    if((long)(platform->Time() - dwellTime) >= 0)
+    {
+      dwellWaiting = false;
+      return true;
+    }
+    return false;
+  }
+      
+  // New dwell - set it up
+      
+  dwellWaiting = true;
+  dwellTime = platform->Time() + dwell;
+  return false;
+}
+
+boolean GCodes::ActOnGcode(GCodeBuffer *gb)
 {
   int code;
+  boolean result = true;
+  unsigned long dwell;
   
   if(gb->Seen('G'))
   {
@@ -119,7 +202,7 @@ void GCodes::ActOnGcode(GCodeBuffer *gb)
       break;
       
     case 4: // Dwell
-      platform->Message(HOST_MESSAGE, "Dwell received\n");
+      result = doDwell(gb);
       break;
       
     case 10: // Set offsets
@@ -157,7 +240,7 @@ void GCodes::ActOnGcode(GCodeBuffer *gb)
       platform->Message(HOST_MESSAGE, gb->Buffer());
       platform->Message(HOST_MESSAGE, "\n");
     }
-    return;
+    return result;
   }
   
   if(gb->Seen('M'))
@@ -179,7 +262,8 @@ void GCodes::ActOnGcode(GCodeBuffer *gb)
       break;
       
     case 24: // Print selected file
-      platform->Message(HOST_MESSAGE, "Print started\n");
+      fileBeingPrinted = fileToPrint;
+      fileToPrint = -1;
       break;
       
     case 82:
@@ -223,7 +307,7 @@ void GCodes::ActOnGcode(GCodeBuffer *gb)
       platform->Message(HOST_MESSAGE, gb->Buffer());
       platform->Message(HOST_MESSAGE, "\n");
     }
-    return;
+    return result;
   }
   
   if(gb->Seen('T'))
@@ -247,24 +331,10 @@ void GCodes::ActOnGcode(GCodeBuffer *gb)
     }
   }
   
+  return result;
 }
 
 
-void GCodes::Spin()
-{
-  if(!active)
-    return;
-    
-  if(webserver->GCodeAvailable())
-  {
-    if(webGCode->Put(webserver->ReadGCode()))
-      ActOnGcode(webGCode);
-  }
-  
-  // TODO - Add processing of GCodes from file
-  
-}
-
 
 boolean GCodes::ReadMove(float* m)
 {
@@ -281,6 +351,8 @@ boolean GCodes::ReadHeat(float* h)
 
 }
 
+//*************************************************************************************
+
 GCodeBuffer::GCodeBuffer(Platform* p)
 { 
   platform = p; 
@@ -345,20 +417,28 @@ float GCodeBuffer::GetFValue()
   return result; 
 }
 
-// Get an Int after a G Code letter
 
-int GCodeBuffer::GetIValue()
+// Get an long after a G Code letter
+
+long GCodeBuffer::GetLValue()
 {
   if(readPointer < 0)
   {
     platform->Message(HOST_MESSAGE, "GCodes: Attempt to read a GCode int before a search.\n");
     return 0;
   }
-  int result = (int)strtol(&gcodeBuffer[readPointer + 1], NULL, 0);
+  long result = strtol(&gcodeBuffer[readPointer + 1], NULL, 0);
   readPointer = -1;
   return result;  
 }
 
+// Get an Int after a G Code letter
+
+int GCodeBuffer::GetIValue()
+{
+  return (int)GetLValue();
+}
+
 char* GCodeBuffer::Buffer()
 {
   return gcodeBuffer;
diff --git a/Move.h b/Move.h
index 796aa7f..e270057 100644
--- a/Move.h
+++ b/Move.h
@@ -74,6 +74,7 @@ class Move
     void Qmove();
     void GetCurrentState(float m[]);
     void Interrupt();
+    boolean AllMovesFinished();
     void InterruptTime();
 
   friend class DDA;
diff --git a/Move.ino b/Move.ino
index ebfabdd..4e41f4a 100644
--- a/Move.ino
+++ b/Move.ino
@@ -223,6 +223,12 @@ void Move::Interrupt()
   dda = NULL;
 }
 
+boolean Move::AllMovesFinished()
+{
+  // TODO - put some code in here
+  return true; 
+}
+
 // This function is never normally called.  It is a test to time
 // the interrupt function.  To activate it, uncomment the line that calls
 // this in Platform.ino.
diff --git a/Platform.h b/Platform.h
index 0193a96..2b4a2e7 100644
--- a/Platform.h
+++ b/Platform.h
@@ -184,7 +184,8 @@ class Platform
   // Communications and data storage; opening something unsupported returns -1.
   
   char* FileList(char* directory); // Returns a ,-separated list of all the files in the named directory (for example on an SD card).
-  int OpenFile(char* fileName, boolean write); // Open a local file (for example on an SD card).
+  //int OpenFile(char* fileName, boolean write); // Open a local file (for example on an SD card).
+  int OpenFile(char* directory, char* fileName, boolean write); // Open a local file (for example on an SD card).
   void GoToEnd(int file); // Position the file at the end (so you can write on the end).
   boolean Read(int file, unsigned char& b);     // Read a single byte from a file into b, 
                                              // returned value is false for EoF, true otherwise
@@ -192,12 +193,11 @@ class Platform
   void Write(int file, char b);  // Write the byte b to a file.
   unsigned long Length(int file); // File size in bytes
   char* GetWebDir(); // Where the htm etc files are
-  char* GetGcodeDir(); // Where the gcodes are
+  char* GetGCodeDir(); // Where the gcodes are
   char* GetSysDir();  // Where the system files are
   char* GetTempDir(); // Where temporary files are
   void Close(int file); // Close a file or device, writing any unwritten buffer contents first.
-  boolean DeleteFile(char* fileName); // Delete a file
-  char* PrependRoot(char* result, char* root, char* fileName);
+  boolean DeleteFile(char* directory, char* fileName); // Delete a file
   
   unsigned char ClientRead(); // Read a byte from the client
   void SendToClient(char* message); // Send string to the host
@@ -242,6 +242,8 @@ class Platform
   
   void InitialiseInterrupts();
   
+  char* CombineName(char* result, char* directory, char* fileName);
+  
   RepRap* reprap;
   
 // DRIVES
@@ -286,6 +288,7 @@ class Platform
   byte* buf[MAX_FILES];
   int bPointer[MAX_FILES];
   char fileList[FILE_LIST_LENGTH];
+  char scratchString[STRING_LENGTH];
   
 // Network connection
 
@@ -316,7 +319,7 @@ inline char* Platform::GetWebDir()
 
 // Where the gcodes are
 
-inline char* Platform::GetGcodeDir()
+inline char* Platform::GetGCodeDir()
 {
   return gcodeDir;
 }
diff --git a/Platform.ino b/Platform.ino
index e90cd55..93f56cd 100644
--- a/Platform.ino
+++ b/Platform.ino
@@ -58,27 +58,6 @@ inline void Platform::Interrupt()
   reprap->Interrupt();  // Put nothing else in this function
 }
 
-
-/*
-void startTimer(Tc *tc, uint32_t channel, IRQn_Type irq, uint32_t frequency) 
-{
-  pmc_set_writeprotect(false);
-  pmc_enable_periph_clk((uint32_t)irq);
-  TC_Configure(tc, channel, TC_CMR_WAVE | TC_CMR_WAVSEL_UP_RC | TC_CMR_TCCLKS_TIMER_CLOCK4);
-  // VARIANT_MCK = 84x10^6 for the Due
-  uint32_t rc = VARIANT_MCK/128/frequency; //128 because we selected TIMER_CLOCK4 above
-  TC_SetRA(tc, channel, rc/2); //50% high, 50% low
-  TC_SetRC(tc, channel, rc);
-  TC_Start(tc, channel);
-  tc->TC_CHANNEL[channel].TC_IER=TC_IER_CPCS;
-  tc->TC_CHANNEL[channel].TC_IDR=~TC_IER_CPCS;
-  NVIC_EnableIRQ(irq);
-}
-*/
-
-
-
-
 //*******************************************************************************************************************
 
 void Platform::Init()
@@ -207,13 +186,13 @@ void Platform::Init()
   active = true;
 }
 
-
+/*
 char* Platform::PrependRoot(char* result, char* root, char* fileName)
 {
   strcpy(result, root);
   return strcat(result, fileName);
 }
-
+*/
 
 // Load settings from local storage; return true if successful, false otherwise
 
@@ -277,6 +256,41 @@ void Platform::SetHeater(char heater, const float& power)
   
 */
 
+char* Platform::CombineName(char* result, char* directory, char* fileName)
+{
+  int out = 0;
+  int in = 0;
+  
+  result[out] = '/';
+  out++;
+  
+  if(directory != NULL)
+  {
+    if(directory[in] == '/')
+      in++;
+    while(directory[in] != 0 && directory[in] != '\n' && directory[in] != '/')
+    {
+      result[out] = directory[in];
+      out++;
+      in++;
+    }
+  }
+  
+  result[out] = '/';
+  out++;
+  
+  in = 0;
+  while(fileName[in] != 0 && fileName[in] != '\n' && fileName[in] != '/')
+  {
+    result[out] = fileName[in];
+    out++;
+    in++;
+  }
+  result[out] = 0;
+  
+  return result;
+}
+
 // List the flat files in a directory.  No sub-directories or recursion.
 
 char* Platform::FileList(char* directory)
@@ -317,15 +331,17 @@ char* Platform::FileList(char* directory)
 }
 
 // Delete a file
-boolean Platform::DeleteFile(char* fileName)
+boolean Platform::DeleteFile(char* directory, char* fileName)
 {
-  return SD.remove(fileName);
+  CombineName(scratchString, directory, fileName);
+  return SD.remove(scratchString);
 }
 
 // Open a local file (for example on an SD card).
 
-int Platform::OpenFile(char* fileName, boolean write)
+int Platform::OpenFile(char* directory, char* fileName, boolean write)
 {
+  CombineName(scratchString, directory, fileName);
   int result = -1;
   for(int i = 0; i < MAX_FILES; i++)
     if(!inUse[i])
@@ -339,7 +355,7 @@ int Platform::OpenFile(char* fileName, boolean write)
       return -1;    
   }
   
-  if(!SD.exists(fileName))
+  if(!SD.exists(scratchString))
   {
     if(!write)
     {
@@ -348,16 +364,16 @@ int Platform::OpenFile(char* fileName, boolean write)
       Message(HOST_MESSAGE, " not found for reading.\n");
       return -1;
     }
-    files[result] = SD.open(fileName, FILE_WRITE);
+    files[result] = SD.open(scratchString, FILE_WRITE);
     bPointer[result] = 0;
   } else
   {
     if(write)
     {
-      files[result] = SD.open(fileName, FILE_WRITE);
+      files[result] = SD.open(scratchString, FILE_WRITE);
       bPointer[result] = 0;
     } else
-      files[result] = SD.open(fileName, FILE_READ);
+      files[result] = SD.open(scratchString, FILE_READ);
   }
 
   inUse[result] = true;
@@ -469,7 +485,7 @@ void Platform::Message(char type, char* message)
   default:
   
   
-    int m = OpenFile(PrependRoot(scratchString, GetWebDir(), MESSAGE_FILE), true);
+    int m = OpenFile(GetWebDir(), MESSAGE_FILE, true);
     GoToEnd(m);
     WriteString(m, message);
     Serial.print(message);
diff --git a/SD-image/gcodes/square.g b/SD-image/gcodes/square.g
new file mode 100644
index 0000000..1869b66
--- /dev/null
+++ b/SD-image/gcodes/square.g
@@ -0,0 +1,9 @@
+G1 X55 Y5 F2000
+G1 X55 Y55
+G1 X5 Y55
+G1 X5 Y5
+G1 X55 Y5
+G1 X55 Y55
+G1 X5 Y55
+G1 X5 Y5
+
diff --git a/SD-image/gcodes/square.g~ b/SD-image/gcodes/square.g~
new file mode 100644
index 0000000..e69de29
diff --git a/Webserver.ino b/Webserver.ino
index bc45e17..d72c0e7 100644
--- a/Webserver.ino
+++ b/Webserver.ino
@@ -132,10 +132,10 @@ boolean Webserver::LoadGcodeBuffer(char* gc, boolean convertWeb)
   if(StringStartsWith(gcodeBuffer, "M23 ")) fileAct |= 2;
   
   if(fileAct) // Delete or print a file?
-  {
+  { 
     if(fileAct == 1) // Delete?
     {
-      if(!platform->DeleteFile(platform->PrependRoot(scratchString, platform->GetGcodeDir(), &gcodeBuffer[4])))
+      if(!platform->DeleteFile(platform->GetGCodeDir(), &gcodeBuffer[4]))
       {
         platform->Message(HOST_MESSAGE, "Unsuccsessful attempt to delete: ");
         platform->Message(HOST_MESSAGE, &gcodeBuffer[4]);
@@ -143,12 +143,11 @@ boolean Webserver::LoadGcodeBuffer(char* gc, boolean convertWeb)
       } 
     } else // Print it
     {
-      reprap.GetGCodes()->QueueFileToPrint(platform->PrependRoot(scratchString, platform->GetGcodeDir(), &gcodeBuffer[4])); 
+      reprap.GetGCodes()->QueueFileToPrint(&gcodeBuffer[4]);
     }
     
     // Check for further G Codes in the string
     
-    gcodePointer = 0;
     while(gcodeBuffer[gcodePointer])
     {
        if(gcodeBuffer[gcodePointer] == '\n')
@@ -199,11 +198,11 @@ void Webserver::SendFile(char* nameOfFileToSend)
     
   if(jsonPointer < 0)
   {
-    fileBeingSent = platform->OpenFile(platform->PrependRoot(scratchString, platform->GetWebDir(), nameOfFileToSend), false);
+    fileBeingSent = platform->OpenFile(platform->GetWebDir(), nameOfFileToSend, false);
     if(fileBeingSent < 0)
     {
       nameOfFileToSend = FOUR04_FILE;
-      fileBeingSent = platform->OpenFile(platform->PrependRoot(scratchString, platform->GetWebDir(), nameOfFileToSend), false);
+      fileBeingSent = platform->OpenFile(platform->GetWebDir(), nameOfFileToSend, false);
     }
     writing = true;
   } 
@@ -321,7 +320,7 @@ void Webserver::GetJsonResponse(char* request)
   
   if(StringStartsWith(request, "files"))
   {
-    char* fileList = platform->FileList(platform->GetGcodeDir());
+    char* fileList = platform->FileList(platform->GetGCodeDir());
     strcpy(jsonResponse, "{\"files\":[");
     strcat(jsonResponse, fileList);
     strcat(jsonResponse, "]}");    
@@ -496,11 +495,11 @@ void Webserver::BlankLineFromClient()
   
   if(receivingPost)
   {
-    postFile = platform->OpenFile(platform->PrependRoot(scratchString, platform->GetGcodeDir(), postFileName), true);
+    postFile = platform->OpenFile(platform->GetGCodeDir(), postFileName, true);
     if(postFile < 0  || !postBoundary[0])
     {
       platform->Message(HOST_MESSAGE, "Can't open file for write or no post boundary: ");
-      platform->Message(HOST_MESSAGE, platform->PrependRoot(scratchString, platform->GetGcodeDir(), postFileName));
+      platform->Message(HOST_MESSAGE, postFileName);
       platform->Message(HOST_MESSAGE, "\n");
       InitialisePost();
     }
@@ -626,7 +625,7 @@ void Webserver::Init()
   
   // Reinitialise the message file
   
-  platform->DeleteFile(platform->PrependRoot(scratchString, platform->GetWebDir(), MESSAGE_FILE));
+  platform->DeleteFile(platform->GetWebDir(), MESSAGE_FILE);
 }
 
 void Webserver::Exit()