diff --git a/Components/9918/Implementation/9918.cpp b/Components/9918/Implementation/9918.cpp
index 4aa3de41a..36398d457 100644
--- a/Components/9918/Implementation/9918.cpp
+++ b/Components/9918/Implementation/9918.cpp
@@ -866,7 +866,31 @@ void Base<personality>::commit_register(int reg, uint8_t value) {
 
 				// Seed timing information if a command was found.
 				if(Storage<personality>::command_) {
-					// TODO.
+					// TODO: eliminate SUPER HACK.
+					// This is currently here primarily to help me to hash out the
+					// proper interface, and also because I'm just not persuaded
+					// that minimum_access_column_ works properly. Why doesn't it
+					// ever end up out of bounds?
+
+
+					// TODO: undo temporary assumption of Graphics Mode 5.
+					uint8_t packed_colour = Storage<personality>::command_context_.colour & 3;
+					packed_colour |= packed_colour << 2;
+					packed_colour |= packed_colour << 4;
+
+					while(!Storage<personality>::command_->done()) {
+						const int address =
+							(Storage<personality>::command_->location.v[0] >> 2) +
+							(Storage<personality>::command_->location.v[1] << 7);
+
+						const uint8_t mask = 0xc0 >> ((Storage<personality>::command_->location.v[0] & 3) << 1);
+						uint8_t v = ram_[address];
+						v &= ~mask;
+						v |= packed_colour & mask;
+						ram_[address] = v;
+
+						Storage<personality>::command_->advance();
+					}
 				}
 
 				// TODO: record logical mode.
diff --git a/Components/9918/Implementation/YamahaCommands.hpp b/Components/9918/Implementation/YamahaCommands.hpp
index 4eacab086..89e785eef 100644
--- a/Components/9918/Implementation/YamahaCommands.hpp
+++ b/Components/9918/Implementation/YamahaCommands.hpp
@@ -59,11 +59,11 @@ struct Command {
 	CommandContext &context;
 	Command(CommandContext &context) : context(context) {}
 
-	/// Request that the fields above are updated given that the previously-request access
-	/// was completed.
-	///
-	/// @returns @c true if another access has been enqueued; @c false if this command is done.
-	virtual bool next() = 0;
+	/// @returns @c true if all output from this command is done; @c false otherwise.
+	virtual bool done() = 0;
+
+	/// Repopulates the fields above with the next action to take.
+	virtual void advance() = 0;
 };
 
 // MARK: - Line drawing.
@@ -104,9 +104,11 @@ struct Line: public Command {
 			location = context.destination;
 		}
 
-		bool next() {
-			if(!duration_) return false;
+		bool done() final {
+			return !duration_;
+		}
 
+		void advance() final {
 			--duration_;
 			cycles = 88;
 			location += major_;
@@ -116,8 +118,6 @@ struct Line: public Command {
 				location += minor_;
 				position_ += denominator_;
 			}
-
-			return true;
 		}
 
 	private: