diff --git a/StaticAnalyser/Acorn/Tape.cpp b/StaticAnalyser/Acorn/Tape.cpp
index cf6104025..62adde4ca 100644
--- a/StaticAnalyser/Acorn/Tape.cpp
+++ b/StaticAnalyser/Acorn/Tape.cpp
@@ -101,13 +101,20 @@ class Acorn1200BaudTapeParser: public StaticAnalyer::TapeParser<WaveType, Symbol
 				return;
 			}
 
-			if(	waves.size() >= 4 &&
-				waves[0] == WaveType::Short &&
-				waves[1] == WaveType::Short &&
-				waves[2] == WaveType::Short &&
-				waves[3] == WaveType::Short)
+			if(waves.size() >= 4)
 			{
-				push_symbol(SymbolType::One, 4);
+				// If this makes a 1, post it.
+				if(	waves[0] == WaveType::Short &&
+					waves[1] == WaveType::Short &&
+					waves[2] == WaveType::Short &&
+					waves[3] == WaveType::Short)
+				{
+					push_symbol(SymbolType::One, 4);
+					return;
+				}
+
+				// Otherwise, eject at least one wave as all options are exhausted.
+				remove_waves(1);
 				return;
 			}
 		}
diff --git a/StaticAnalyser/TapeParser.hpp b/StaticAnalyser/TapeParser.hpp
index 7adc3c20c..581be2fab 100644
--- a/StaticAnalyser/TapeParser.hpp
+++ b/StaticAnalyser/TapeParser.hpp
@@ -83,7 +83,18 @@ template <typename WaveType, typename SymbolType> class TapeParser {
 		}
 
 	private:
+		/*!
+			Should be implemented by subclasses. Consumes @c pulse. Is likely either to call @c push_wave
+			or to take no action.
+		*/
 		virtual void process_pulse(Storage::Tape::Tape::Pulse pulse) = 0;
+
+		/*!
+			Should be implemented by subclasses. Inspects @c waves for a potential new symbol. If one is
+			found should call @c push_symbol. May wish alternatively to call @c remove_waves to have entries
+			removed from the start of @c waves that cannot form a valid symbol. Need not do anything while
+			the waves at the start of @c waves may end up forming a symbol but the symbol is not yet complete.
+		*/
 		virtual void inspect_waves(const std::vector<WaveType> &waves) = 0;
 
 		std::vector<WaveType> _wave_queue;