diff --git a/Components/9918/Implementation/Fetch.hpp b/Components/9918/Implementation/Fetch.hpp
index f8efc0034..62f3762ae 100644
--- a/Components/9918/Implementation/Fetch.hpp
+++ b/Components/9918/Implementation/Fetch.hpp
@@ -472,6 +472,16 @@ template<bool use_end> void Base<personality>::fetch_sms(int start, int end) {
 
 // TODO.
 
+namespace {
+
+// This emulator treats position 0 as being immediately after the standard pixel area.
+// i.e. offset 1282 on Grauw's http://map.grauw.nl/articles/vdp-vram-timing/vdp-timing.png
+constexpr int grauw_to_internal(int offset) {
+	return (offset + 1368 - 1282) % 1368;
+}
+
+}
+
 template <Personality personality>
 template<bool use_end> void Base<personality>::fetch_yamaha_refresh(int start, int end) {
 	(void)start;
@@ -499,6 +509,107 @@ template<bool use_end, bool fetch_sprites> void Base<personality>::fetch_yamaha(
 		can occur.
 	*/
 
+	// This emulator treats position 0 as being immediately after the standard pixel area.
+	// i.e. offset 1282 on Grauw's http://map.grauw.nl/articles/vdp-vram-timing/vdp-timing.png
+	//
+	// That being the case...
+	//
+	// Data blocks are located at:
+	//
+	//		194
+
+	/// Describes an _observable_ memory access event. i.e. anything that it is safe
+	/// (and convenient) to treat as atomic in between external slots.
+	struct Event {
+		/// Offset of the _beginning_ of the event. Not completely arbitrarily: this is when
+		/// external data must be ready by in order to take part in those slots.
+		int offset;
+		enum class Type {
+			External,
+			DataBlock,
+		} type;
+
+		constexpr Event(int offset, Type type) noexcept :
+			offset(grauw_to_internal(offset)),
+			type(type) {}
+	};
+	constexpr Event no_sprites_events[] = {
+		Event(1282, Event::Type::External),
+		Event(1290, Event::Type::External),
+		Event(1298, Event::Type::External),
+		Event(1306, Event::Type::External),
+		Event(1314, Event::Type::External),
+		Event(1322, Event::Type::External),
+		Event(1332, Event::Type::External),
+		Event(1342, Event::Type::External),
+		Event(1350, Event::Type::External),
+		Event(1358, Event::Type::External),
+		Event(1366, Event::Type::External),
+
+		Event(6, Event::Type::External),
+		Event(14, Event::Type::External),
+		Event(22, Event::Type::External),
+		Event(30, Event::Type::External),
+		Event(38, Event::Type::External),
+		Event(46, Event::Type::External),
+		Event(54, Event::Type::External),
+		Event(62, Event::Type::External),
+		Event(70, Event::Type::External),
+		Event(78, Event::Type::External),
+		Event(86, Event::Type::External),
+		Event(94, Event::Type::External),
+		Event(102, Event::Type::External),
+		Event(110, Event::Type::External),
+		Event(118, Event::Type::External),
+
+		Event(162, Event::Type::External),
+		Event(170, Event::Type::External),
+		Event(182, Event::Type::External),
+		Event(188, Event::Type::External),
+		// Omitted: dummy data block. Is not observable.
+		Event(214, Event::Type::External),
+		Event(220, Event::Type::External),
+
+		Event(226, Event::Type::DataBlock),	Event(246, Event::Type::External),	Event(252, Event::Type::External),
+		Event(258, Event::Type::DataBlock),	Event(278, Event::Type::External),	// Omitted: refresh.
+		Event(290, Event::Type::DataBlock),	Event(310, Event::Type::External),	Event(316, Event::Type::External),
+		Event(322, Event::Type::DataBlock),	Event(342, Event::Type::External),	Event(348, Event::Type::External),
+		Event(354, Event::Type::DataBlock),	Event(374, Event::Type::External),	Event(380, Event::Type::External),
+		Event(386, Event::Type::DataBlock),	Event(406, Event::Type::External),	// Omitted: refresh.
+		Event(418, Event::Type::DataBlock),	Event(438, Event::Type::External),	Event(444, Event::Type::External),
+		Event(450, Event::Type::DataBlock),	Event(470, Event::Type::External),	Event(476, Event::Type::External),
+
+		Event(482, Event::Type::DataBlock),	Event(502, Event::Type::External),	Event(508, Event::Type::External),
+		Event(514, Event::Type::DataBlock),	Event(534, Event::Type::External),	// Omitted: refresh.
+		Event(546, Event::Type::DataBlock),	Event(566, Event::Type::External),	Event(572, Event::Type::External),
+		Event(578, Event::Type::DataBlock),	Event(598, Event::Type::External),	Event(604, Event::Type::External),
+		Event(610, Event::Type::DataBlock),	Event(630, Event::Type::External),	Event(636, Event::Type::External),
+		Event(642, Event::Type::DataBlock),	Event(662, Event::Type::External),	// Omitted: refresh.
+		Event(674, Event::Type::DataBlock),	Event(694, Event::Type::External),	Event(700, Event::Type::External),
+		Event(706, Event::Type::DataBlock),	Event(726, Event::Type::External),	Event(732, Event::Type::External),
+
+		Event(738, Event::Type::DataBlock),	Event(758, Event::Type::External),	Event(764, Event::Type::External),
+		Event(770, Event::Type::DataBlock),	Event(790, Event::Type::External),	// Omitted: refresh.
+		Event(802, Event::Type::DataBlock),	Event(822, Event::Type::External),	Event(828, Event::Type::External),
+		Event(834, Event::Type::DataBlock),	Event(854, Event::Type::External),	Event(860, Event::Type::External),
+		Event(866, Event::Type::DataBlock),	Event(886, Event::Type::External),	Event(892, Event::Type::External),
+		Event(898, Event::Type::DataBlock),	Event(918, Event::Type::External),	// Omitted: refresh.
+		Event(930, Event::Type::DataBlock),	Event(950, Event::Type::External),	Event(956, Event::Type::External),
+		Event(962, Event::Type::DataBlock),	Event(982, Event::Type::External),	Event(988, Event::Type::External),
+
+		Event(994, Event::Type::DataBlock),	Event(1014, Event::Type::External),	Event(1020, Event::Type::External),
+		Event(1026, Event::Type::DataBlock),	Event(1046, Event::Type::External),	// Omitted: refresh.
+		Event(1058, Event::Type::DataBlock),	Event(1078, Event::Type::External),	Event(1084, Event::Type::External),
+		Event(1090, Event::Type::DataBlock),	Event(1110, Event::Type::External),	Event(1116, Event::Type::External),
+		Event(1122, Event::Type::DataBlock),	Event(1142, Event::Type::External),	Event(1148, Event::Type::External),
+		Event(1154, Event::Type::DataBlock),	Event(1174, Event::Type::External),	// Omitted: refresh.
+		Event(1186, Event::Type::DataBlock),	Event(1206, Event::Type::External),	Event(1212, Event::Type::External),
+		Event(1218, Event::Type::DataBlock),
+
+		Event(1266, Event::Type::External),
+		Event(1274, Event::Type::External),
+ 	};
+
 	(void)start;
 	(void)end;
 }