diff --git a/Storage/Disk/Encodings/MFM.cpp b/Storage/Disk/Encodings/MFM.cpp
index efb0797b2..4e5180b23 100644
--- a/Storage/Disk/Encodings/MFM.cpp
+++ b/Storage/Disk/Encodings/MFM.cpp
@@ -9,42 +9,3 @@
 #include "MFM.hpp"
 
 using namespace Storage::Encodings;
-
-void Shifter::add_sync()
-{
-	// i.e. 0100 0100 1000 1001
-	output = (uint16_t)((output << 15) | 0x4489);
-}
-
-void MFMShifter::shift(uint8_t input)
-{
-	uint16_t spread_value =
-		(uint16_t)(
-			((input & 0x01) << 0) |
-			((input & 0x02) << 1) |
-			((input & 0x04) << 2) |
-			((input & 0x08) << 3) |
-			((input & 0x10) << 4) |
-			((input & 0x20) << 5) |
-			((input & 0x40) << 6) |
-			((input & 0x80) << 7)
-		);
-	uint16_t or_bits = (uint16_t)((spread_value << 1) | (spread_value >> 1) | (output << 15));
-	output = spread_value | ((~or_bits) & 0xaaaa);
-}
-
-void FMShifter::shift(uint8_t input)
-{
-	output =
-		(uint16_t)(
-			((input & 0x01) << 0) |
-			((input & 0x02) << 1) |
-			((input & 0x04) << 2) |
-			((input & 0x08) << 3) |
-			((input & 0x10) << 4) |
-			((input & 0x20) << 5) |
-			((input & 0x40) << 6) |
-			((input & 0x80) << 7) |
-			0xaaaa
-		);
-}
diff --git a/Storage/Disk/Encodings/MFM.hpp b/Storage/Disk/Encodings/MFM.hpp
index 2e3c8f2c4..3c07e5dd2 100644
--- a/Storage/Disk/Encodings/MFM.hpp
+++ b/Storage/Disk/Encodings/MFM.hpp
@@ -14,21 +14,98 @@
 namespace Storage {
 namespace Encodings {
 
-class Shifter {
+template <class T> class Shifter {
 	public:
-		virtual void shift(uint8_t input) = 0;
-		void add_sync();
-		uint16_t output;
+		virtual void add_byte(uint8_t input) = 0;
+		virtual void add_index_address_mark() = 0;
+		virtual void add_ID_address_mark() = 0;
+		virtual void add_data_address_mark() = 0;
+		virtual void add_deleted_data_address_mark() = 0;
+
+	protected:
+		// override me!
+		void output_short(uint16_t value);
 };
 
-class MFMShifter: public Shifter {
+template <class T> class MFMShifter: public Shifter<T> {
 	public:
-		void shift(uint8_t input);
+		void add_byte(uint8_t input) {
+			uint16_t spread_value =
+				(uint16_t)(
+					((input & 0x01) << 0) |
+					((input & 0x02) << 1) |
+					((input & 0x04) << 2) |
+					((input & 0x08) << 3) |
+					((input & 0x10) << 4) |
+					((input & 0x20) << 5) |
+					((input & 0x40) << 6) |
+					((input & 0x80) << 7)
+				);
+			uint16_t or_bits = (uint16_t)((spread_value << 1) | (spread_value >> 1) | (output_ << 15));
+			output_ = spread_value | ((~or_bits) & 0xaaaa);
+			static_cast<T *>(this)->output_short(output_);
+		}
+
+		void add_index_address_mark() {
+			static_cast<T *>(this)->output_short(output_ = 0x5224);
+			add_byte(0xfc);
+		}
+
+		void add_ID_address_mark() {
+			static_cast<T *>(this)->output_short(output_ = 0x4489);
+			add_byte(0xfe);
+		}
+
+		void add_data_address_mark() {
+			static_cast<T *>(this)->output_short(output_ = 0x4489);
+			add_byte(0xfb);
+		}
+
+		void add_deleted_data_address_mark() {
+			static_cast<T *>(this)->output_short(output_ = 0x4489);
+			add_byte(0xf8);
+		}
+
+	private:
+		uint16_t output_;
 };
 
-class FMShifter: public Shifter {
+template <class T> class FMShifter: public Shifter<T> {
 	public:
-		void shift(uint8_t input);
+		void add_byte(uint8_t input) {
+			static_cast<T *>(this)->output_short(
+				(uint16_t)(
+					((input & 0x01) << 1) |
+					((input & 0x02) << 2) |
+					((input & 0x04) << 3) |
+					((input & 0x08) << 4) |
+					((input & 0x10) << 5) |
+					((input & 0x20) << 6) |
+					((input & 0x40) << 7) |
+					((input & 0x80) << 8) |
+					0x5555
+				));
+		}
+
+		void add_index_address_mark() {
+			// data 0xfc, with clock 0xd7 => 1111 1100 with clock 1101 0111 => 1111 1011 1011 0101
+			static_cast<T *>(this)->output_short(0xfbb5);
+		}
+
+		void add_ID_address_mark() {
+			// data 0xfe, with clock 0xc7 => 1111 1110 with clock 1100 0111 => 1111 1010 1011 1101
+			static_cast<T *>(this)->output_short(0xfabd);
+		}
+
+		void add_data_address_mark() {
+			// data 0xfb, with clock 0xc7 => 1111 1011 with clock 1100 0111 => 1111 1010 1001 1111
+			static_cast<T *>(this)->output_short(0xfa9f);
+		}
+
+		void add_deleted_data_address_mark() {
+			// data 0xf8, with clock 0xc7 => 1111 1000 with clock 1100 0111 => 1111 1010 1001 0101
+			static_cast<T *>(this)->output_short(0xfa95);
+		}
 };
 
 }