From 7e2b4554eacccec3d0db226741bba77439d0253b Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Mon, 15 Aug 2016 20:08:50 -0400
Subject: [PATCH] This likely forms the Commodore dipoles correctly. It just
 stays stuck in leader tone forever is all.

---
 Storage/Tape/Formats/TapePRG.cpp | 27 +++++++++++++++++++++++++--
 Storage/Tape/Formats/TapePRG.hpp | 14 ++++++++------
 2 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/Storage/Tape/Formats/TapePRG.cpp b/Storage/Tape/Formats/TapePRG.cpp
index 07d89ee2f..6c1370cdf 100644
--- a/Storage/Tape/Formats/TapePRG.cpp
+++ b/Storage/Tape/Formats/TapePRG.cpp
@@ -12,7 +12,7 @@
 
 using namespace Storage;
 
-TapePRG::TapePRG(const char *file_name) : _file(nullptr)
+TapePRG::TapePRG(const char *file_name) : _file(nullptr), _bitPhase(3)
 {
 	struct stat file_stats;
 	stat(file_name, &file_stats);
@@ -39,11 +39,34 @@ TapePRG::~TapePRG()
 
 Tape::Pulse TapePRG::get_next_pulse()
 {
+	static const unsigned int leader_zero_length = 179;
+	static const unsigned int zero_length = 169;
+	static const unsigned int one_length = 247;
+	static const unsigned int word_marker_length = 328;
+
+	_bitPhase = (_bitPhase+1)&3;
+	if(!_bitPhase) get_next_output_token();
+
 	Tape::Pulse pulse;
+	switch(_outputToken)
+	{
+		case Leader:		pulse.length.length = leader_zero_length;								break;
+		case Zero:			pulse.length.length = (_bitPhase&2) ? one_length : zero_length;			break;
+		case One:			pulse.length.length = (_bitPhase&2) ? zero_length : one_length;			break;
+		case WordMarker:	pulse.length.length = (_bitPhase&2) ? one_length : word_marker_length;	break;
+	}
+	pulse.length.clock_rate = 1000000;
+	pulse.type = (_bitPhase&1) ? Pulse::Low : Pulse::High;
 	return pulse;
 }
 
 void TapePRG::reset()
 {
-	// TODO
+	_bitPhase = 3;
+	fseek(_file, 2, SEEK_SET);
+}
+
+void TapePRG::get_next_output_token()
+{
+	_outputToken = Leader;
 }
diff --git a/Storage/Tape/Formats/TapePRG.hpp b/Storage/Tape/Formats/TapePRG.hpp
index 1aaabfc80..44493437f 100644
--- a/Storage/Tape/Formats/TapePRG.hpp
+++ b/Storage/Tape/Formats/TapePRG.hpp
@@ -45,12 +45,14 @@ class TapePRG: public Tape {
 			FilePhaseHeader
 		} _filePhase;
 
-		enum BitPhase {
-			BitPhase0,
-			BitPhase1,
-			BitPhase2,
-			BitPhase3
-		} _bitPhase;
+		int _bitPhase;
+		enum OutputToken {
+			Leader,
+			Zero,
+			One,
+			WordMarker
+		} _outputToken;
+		void get_next_output_token();
 };
 
 }