diff --git a/libraries/DataFlash/DataFlash.h b/libraries/DataFlash/DataFlash.h
index bd0b27c9d4..879e779b4d 100644
--- a/libraries/DataFlash/DataFlash.h
+++ b/libraries/DataFlash/DataFlash.h
@@ -26,7 +26,7 @@ class DataFlash_Class
 	virtual void WriteLong(int32_t data) = 0;
 
 	// Read methods
-	virtual void StartRead(int PageAdr) = 0;
+	virtual void StartRead(int16_t PageAdr) = 0;
 	virtual unsigned char ReadByte() = 0;
 	virtual int16_t ReadInt() = 0;
 	virtual int32_t ReadLong() = 0;
diff --git a/libraries/DataFlash/DataFlash_APM1.cpp b/libraries/DataFlash/DataFlash_APM1.cpp
index f6e414546f..696bfedce9 100644
--- a/libraries/DataFlash/DataFlash_APM1.cpp
+++ b/libraries/DataFlash/DataFlash_APM1.cpp
@@ -124,7 +124,7 @@ byte DataFlash_APM1::ReadStatus()
 
 
 inline
-unsigned int DataFlash_APM1::PageSize()
+uint16_t DataFlash_APM1::PageSize()
 {
   return(528-((ReadStatusReg()&0x01)<<4));  // if first bit 1 trhen 512 else 528 bytes
 }
@@ -136,7 +136,7 @@ void DataFlash_APM1::WaitReady()
   while(!ReadStatus());
 }
 
-void DataFlash_APM1::PageToBuffer(unsigned char BufferNum, unsigned int PageAdr)
+void DataFlash_APM1::PageToBuffer(unsigned char BufferNum, uint16_t PageAdr)
 {
   dataflash_CS_active();     // activate dataflash command decoder
 
@@ -163,7 +163,7 @@ void DataFlash_APM1::PageToBuffer(unsigned char BufferNum, unsigned int PageAdr)
 
 }
 
-void DataFlash_APM1::BufferToPage (unsigned char BufferNum, unsigned int PageAdr, unsigned char wait)
+void DataFlash_APM1::BufferToPage (unsigned char BufferNum, uint16_t PageAdr, unsigned char wait)
 {
   dataflash_CS_active();     // activate dataflash command decoder
 
@@ -191,7 +191,7 @@ void DataFlash_APM1::BufferToPage (unsigned char BufferNum, unsigned int PageAdr
   dataflash_CS_inactive();	//deactivate dataflash command decoder
 }
 
-void DataFlash_APM1::BufferWrite (unsigned char BufferNum, unsigned int IntPageAdr, unsigned char Data)
+void DataFlash_APM1::BufferWrite (unsigned char BufferNum, uint16_t IntPageAdr, unsigned char Data)
 {
   dataflash_CS_active();     // activate dataflash command decoder
 
@@ -207,7 +207,7 @@ void DataFlash_APM1::BufferWrite (unsigned char BufferNum, unsigned int IntPageA
   dataflash_CS_inactive();   // disable dataflash command decoder
 }
 
-unsigned char DataFlash_APM1::BufferRead (unsigned char BufferNum, unsigned int IntPageAdr)
+unsigned char DataFlash_APM1::BufferRead (unsigned char BufferNum, uint16_t IntPageAdr)
 {
   byte tmp;
 
@@ -229,7 +229,7 @@ unsigned char DataFlash_APM1::BufferRead (unsigned char BufferNum, unsigned int
 }
 // *** END OF INTERNAL FUNCTIONS ***
 
-void DataFlash_APM1::PageErase (unsigned int PageAdr)
+void DataFlash_APM1::PageErase (uint16_t PageAdr)
 {
   dataflash_CS_active();     // activate dataflash command decoder
   SPI.transfer(DF_PAGE_ERASE);   // Command
@@ -269,7 +269,7 @@ void DataFlash_APM1::ChipErase ()
 }
 
 // *** DATAFLASH PUBLIC FUNCTIONS ***
-void DataFlash_APM1::StartWrite(int PageAdr)
+void DataFlash_APM1::StartWrite(int16_t PageAdr)
 {
   df_BufferNum=1;
   df_BufferIdx=4;
@@ -342,13 +342,13 @@ void DataFlash_APM1::WriteByte(byte data)
     }
 }
 
-void DataFlash_APM1::WriteInt(int data)
+void DataFlash_APM1::WriteInt(int16_t data)
 {
   WriteByte(data>>8);   // High byte
   WriteByte(data&0xFF); // Low byte
 }
 
-void DataFlash_APM1::WriteLong(long data)
+void DataFlash_APM1::WriteLong(int32_t data)
 {
   WriteByte(data>>24);   // First byte
   WriteByte(data>>16);
@@ -357,18 +357,18 @@ void DataFlash_APM1::WriteLong(long data)
 }
 
 // Get the last page written to
-int DataFlash_APM1::GetWritePage()
+int16_t DataFlash_APM1::GetWritePage()
 {
   return(df_PageAdr);
 }
 
 // Get the last page read
-int DataFlash_APM1::GetPage()
+int16_t DataFlash_APM1::GetPage()
 {
   return(df_Read_PageAdr-1);
 }
 
-void DataFlash_APM1::StartRead(int PageAdr)
+void DataFlash_APM1::StartRead(int16_t PageAdr)
 {
   df_Read_BufferNum=1;
   df_Read_BufferIdx=4;
@@ -412,24 +412,24 @@ byte DataFlash_APM1::ReadByte()
   return result;
 }
 
-int DataFlash_APM1::ReadInt()
+int16_t DataFlash_APM1::ReadInt()
 {
-  int result;
+  uint16_t result;
 
   result = ReadByte();               // High byte
   result = (result<<8) | ReadByte(); // Low byte
-  return result;
+  return (int16_t)result;
 }
 
-long DataFlash_APM1::ReadLong()
+int32_t DataFlash_APM1::ReadLong()
 {
-  long result;
+  uint32_t result;
 
   result = ReadByte();               // First byte
   result = (result<<8) | ReadByte();
   result = (result<<8) | ReadByte();
   result = (result<<8) | ReadByte(); // Last byte
-  return result;
+  return (int32_t)result;
 }
 
 void DataFlash_APM1::SetFileNumber(uint16_t FileNumber)
diff --git a/libraries/DataFlash/DataFlash_APM1.h b/libraries/DataFlash/DataFlash_APM1.h
index be5aeaf8ae..42a3c6d9d1 100644
--- a/libraries/DataFlash/DataFlash_APM1.h
+++ b/libraries/DataFlash/DataFlash_APM1.h
@@ -34,7 +34,7 @@ class DataFlash_APM1 : public DataFlash_Class
 	unsigned char df_manufacturer;
 	unsigned char df_device_0;
 	unsigned char df_device_1;
-	unsigned int df_PageSize;
+	uint16_t df_PageSize;
 
 	DataFlash_APM1(); // Constructor
 	void Init();
@@ -51,7 +51,7 @@ class DataFlash_APM1 : public DataFlash_Class
 	void WriteLong(int32_t data);
 
 	// Read methods
-	void StartRead(int PageAdr);
+	void StartRead(int16_t PageAdr);
 	unsigned char ReadByte();
 	int16_t ReadInt();
 	int32_t ReadLong();
diff --git a/libraries/DataFlash/DataFlash_Purple.cpp b/libraries/DataFlash/DataFlash_Purple.cpp
index 6626be20b8..1f4b757f26 100644
--- a/libraries/DataFlash/DataFlash_Purple.cpp
+++ b/libraries/DataFlash/DataFlash_Purple.cpp
@@ -153,9 +153,9 @@ void DataFlash_Purple::ReadManufacturerID()
 }
 
 // This function return 1 if Card is inserted on SD slot
-int DataFlash_Purple::CardInserted()
+bool DataFlash_Purple::CardInserted()
 {
-    return (!digitalRead(DF_CARDDETECT));
+    return (digitalRead(DF_CARDDETECT) != 0);
 }
 
 // Read the status register
@@ -178,7 +178,7 @@ byte DataFlash_Purple::ReadStatus()
 
 
 inline
-unsigned int DataFlash_Purple::PageSize()
+uint16_t DataFlash_Purple::PageSize()
 {
   return(528-((ReadStatusReg()&0x01)<<4));  // if first bit 1 trhen 512 else 528 bytes
 }
@@ -190,7 +190,7 @@ void DataFlash_Purple::WaitReady()
   while(!ReadStatus());
 }
 
-void DataFlash_Purple::PageToBuffer(unsigned char BufferNum, unsigned int PageAdr)
+void DataFlash_Purple::PageToBuffer(unsigned char BufferNum, uint16_t PageAdr)
 {
   CS_inactive();
   CS_active();
@@ -214,7 +214,7 @@ void DataFlash_Purple::PageToBuffer(unsigned char BufferNum, unsigned int PageAd
   while(!ReadStatus());  //monitor the status register, wait until busy-flag is high
 }
 
-void DataFlash_Purple::BufferToPage (unsigned char BufferNum, unsigned int PageAdr, unsigned char wait)
+void DataFlash_Purple::BufferToPage (unsigned char BufferNum, uint16_t PageAdr, unsigned char wait)
 {
   CS_inactive();     // Reset dataflash command decoder
   CS_active();
@@ -241,7 +241,7 @@ void DataFlash_Purple::BufferToPage (unsigned char BufferNum, unsigned int PageA
 	while(!ReadStatus());  //monitor the status register, wait until busy-flag is high
 }
 
-void DataFlash_Purple::BufferWrite (unsigned char BufferNum, unsigned int IntPageAdr, unsigned char Data)
+void DataFlash_Purple::BufferWrite (unsigned char BufferNum, uint16_t IntPageAdr, unsigned char Data)
 {
   CS_inactive();   // Reset dataflash command decoder
   CS_active();
@@ -256,7 +256,7 @@ void DataFlash_Purple::BufferWrite (unsigned char BufferNum, unsigned int IntPag
   SPI_transfer(Data);				 //write data byte
 }
 
-unsigned char DataFlash_Purple::BufferRead (unsigned char BufferNum, unsigned int IntPageAdr)
+unsigned char DataFlash_Purple::BufferRead (unsigned char BufferNum, uint16_t IntPageAdr)
 {
   byte tmp;
 
@@ -277,7 +277,7 @@ unsigned char DataFlash_Purple::BufferRead (unsigned char BufferNum, unsigned in
 }
 // *** END OF INTERNAL FUNCTIONS ***
 
-void DataFlash_Purple::PageErase (unsigned int PageAdr)
+void DataFlash_Purple::PageErase (uint16_t PageAdr)
 {
   CS_inactive();																//make sure to toggle CS signal in order
   CS_active();																//to reset Dataflash command decoder
@@ -314,7 +314,7 @@ void DataFlash_Purple::ChipErase ()
 }
 
 // *** DATAFLASH PUBLIC FUNCTIONS ***
-void DataFlash_Purple::StartWrite(int PageAdr)
+void DataFlash_Purple::StartWrite(int16_t PageAdr)
 {
   df_BufferNum=1;
   df_BufferIdx=0;
@@ -376,13 +376,13 @@ void DataFlash_Purple::WriteByte(byte data)
     }
 }
 
-void DataFlash_Purple::WriteInt(int data)
+void DataFlash_Purple::WriteInt(int16_t data)
 {
   WriteByte(data>>8);   // High byte
   WriteByte(data&0xFF); // Low byte
 }
 
-void DataFlash_Purple::WriteLong(long data)
+void DataFlash_Purple::WriteLong(int32_t data)
 {
   WriteByte(data>>24);   // First byte
   WriteByte(data>>16);
@@ -391,18 +391,18 @@ void DataFlash_Purple::WriteLong(long data)
 }
 
 // Get the last page written to
-int DataFlash_Purple::GetWritePage()
+int16_t DataFlash_Purple::GetWritePage()
 {
   return(df_PageAdr);
 }
 
 // Get the last page read
-int DataFlash_Purple::GetPage()
+int16_t DataFlash_Purple::GetPage()
 {
   return(df_Read_PageAdr-1);
 }
 
-void DataFlash_Purple::StartRead(int PageAdr)
+void DataFlash_Purple::StartRead(int16_t PageAdr)
 {
   df_Read_BufferNum=1;
   df_Read_BufferIdx=0;
@@ -433,22 +433,22 @@ byte DataFlash_Purple::ReadByte()
   return result;
 }
 
-int DataFlash_Purple::ReadInt()
+int16_t DataFlash_Purple::ReadInt()
 {
-  int result;
+  uint16_t result;
 
   result = ReadByte();               // High byte
   result = (result<<8) | ReadByte(); // Low byte
-  return result;
+  return (int16_t)result;
 }
 
-long DataFlash_Purple::ReadLong()
+int32_t DataFlash_Purple::ReadLong()
 {
-  long result;
+  uint32_t result;
 
   result = ReadByte();               // First byte
   result = (result<<8) | ReadByte();
   result = (result<<8) | ReadByte();
   result = (result<<8) | ReadByte(); // Last byte
-  return result;
+  return (int32_t)result;
 }
diff --git a/libraries/DataFlash/DataFlash_Purple.h b/libraries/DataFlash/DataFlash_Purple.h
index 96f4740a47..5966d02f39 100644
--- a/libraries/DataFlash/DataFlash_Purple.h
+++ b/libraries/DataFlash/DataFlash_Purple.h
@@ -19,14 +19,14 @@ class DataFlash_Purple : public DataFlash_Class
 	unsigned char df_Read_END;
 	unsigned char df_Stop_Write;
 	//Methods
-	unsigned char BufferRead (unsigned char BufferNum, unsigned int IntPageAdr);
-	void BufferWrite (unsigned char BufferNum, unsigned int IntPageAdr, unsigned char Data);
-	void BufferToPage (unsigned char BufferNum, unsigned int PageAdr, unsigned char wait);
-	void PageToBuffer(unsigned char BufferNum, unsigned int PageAdr);
+	unsigned char BufferRead (unsigned char BufferNum, uint16_t IntPageAdr);
+	void BufferWrite (unsigned char BufferNum, uint16_t IntPageAdr, unsigned char Data);
+	void BufferToPage (unsigned char BufferNum, uint16_t PageAdr, unsigned char wait);
+	void PageToBuffer(unsigned char BufferNum, uint16_t PageAdr);
 	void WaitReady();
 	unsigned char ReadStatusReg();
 	unsigned char ReadStatus();
-	unsigned int PageSize();
+	uint16_t PageSize();
 
 	unsigned char SPI_transfer(unsigned char data);
 	void CS_inactive();
@@ -37,28 +37,28 @@ class DataFlash_Purple : public DataFlash_Class
 	unsigned char df_manufacturer;
 	unsigned char df_device_0;
 	unsigned char df_device_1;
-	unsigned int df_PageSize;
+	uint16_t df_PageSize;
 
 	DataFlash_Purple(); // Constructor
 	void Init();
 	void ReadManufacturerID();
-    int CardInserted();
-	int GetPage();
-	int GetWritePage();
-	void PageErase (unsigned int PageAdr);
+	bool CardInserted();
+	int16_t GetPage();
+	int16_t GetWritePage();
+	void PageErase (uint16_t PageAdr);
 	void ChipErase ();
 	// Write methods
-	void StartWrite(int PageAdr);
+	void StartWrite(int16_t PageAdr);
 	void FinishWrite();
 	void WriteByte(unsigned char data);
-	void WriteInt(int data);
-	void WriteLong(long data);
+	void WriteInt(int16_t data);
+	void WriteLong(int32_t data);
 
 	// Read methods
-	void StartRead(int PageAdr);
+	void StartRead(int16_t PageAdr);
 	unsigned char ReadByte();
-	int ReadInt();
-	long ReadLong();
+	int16_t ReadInt();
+	int32_t ReadLong();
 };
 
 #endif