diff --git a/Components/9918/9918.cpp b/Components/9918/9918.cpp
index 0f3c91852..640596409 100644
--- a/Components/9918/9918.cpp
+++ b/Components/9918/9918.cpp
@@ -89,14 +89,12 @@ constexpr ReverseTable reverse_table;
 }
 
 template <Personality personality>
-Base<personality>::Base(Personality p) :
-	personality_(p),
+Base<personality>::Base() :
 	crt_(CRTCyclesPerLine, CRTCyclesDivider, Outputs::Display::Type::NTSC60, Outputs::Display::InputDataType::Red8Green8Blue8) {
 	// Unimaginatively, this class just passes RGB through to the shader. Investigation is needed
 	// into whether there's a more natural form. It feels unlikely given the diversity of chips modelled.
 
-	ram_.resize(memory_size(p));
-	if(is_sega_vdp(personality_)) {
+	if constexpr (is_sega_vdp(personality)) {
 		mode_timing_.line_interrupt_position = 64;
 
 		mode_timing_.end_of_frame_interrupt_position.column = 63;
@@ -112,8 +110,7 @@ Base<personality>::Base(Personality p) :
 }
 
 template <Personality personality>
-TMS9918<personality>::TMS9918(Personality p):
-	Base<personality>(p) {
+TMS9918<personality>::TMS9918() {
 	this->crt_.set_display_type(Outputs::Display::DisplayType::RGB);
 	this->crt_.set_visible_area(Outputs::Display::Rect(0.07f, 0.0375f, 0.875f, 0.875f));
 
@@ -514,7 +511,7 @@ template <Personality personality>
 void Base<personality>::output_border(int cycles, uint32_t cram_dot) {
 	cycles *= 4;
 	const uint32_t border_colour =
-		is_sega_vdp(personality_) ?
+		is_sega_vdp(personality) ?
 			master_system_.colour_ram[16 + background_colour_] :
 			palette[background_colour_];
 
diff --git a/Components/9918/9918.hpp b/Components/9918/9918.hpp
index 31db277e1..8888d8767 100644
--- a/Components/9918/9918.hpp
+++ b/Components/9918/9918.hpp
@@ -61,7 +61,7 @@ template <Personality personality> class TMS9918: public Base<personality> {
 			Constructs an instance of the drive controller that behaves according to personality @c p.
 			@param p The type of controller to emulate.
 		*/
-		TMS9918(Personality p);
+		TMS9918();
 
 		/*! Sets the TV standard for this TMS, if that is hard-coded in hardware. */
 		void set_tv_standard(TVStandard standard);
diff --git a/Components/9918/Implementation/9918Base.hpp b/Components/9918/Implementation/9918Base.hpp
index 552005383..496f30ddf 100644
--- a/Components/9918/Implementation/9918Base.hpp
+++ b/Components/9918/Implementation/9918Base.hpp
@@ -12,6 +12,7 @@
 #include "../../../Outputs/CRT/CRT.hpp"
 #include "../../../ClockReceiver/ClockReceiver.hpp"
 
+#include <array>
 #include <cassert>
 #include <cstdint>
 #include <memory>
@@ -158,14 +159,13 @@ template <Personality personality> class Base {
 			palette_pack(255, 255, 255)
 		};
 
-		Base(Personality p);
+		Base();
 
-		const Personality personality_;
 		Outputs::CRT::CRT crt_;
 		TVStandard tv_standard_ = TVStandard::NTSC;
 
 		// Holds the contents of this VDP's connected DRAM.
-		std::vector<uint8_t> ram_;
+		std::array<uint8_t, memory_size(personality)> ram_;
 
 		// Holds the state of the DRAM/CRAM-access mechanism.
 		uint16_t ram_pointer_ = 0;
@@ -312,10 +312,12 @@ template <Personality personality> class Base {
 				return;
 			}
 
-			if(is_sega_vdp(personality_) && master_system_.mode4_enable) {
-				screen_mode_ = ScreenMode::SMSMode4;
-				mode_timing_.maximum_visible_sprites = 8;
-				return;
+			if constexpr (is_sega_vdp(personality)) {
+				if(master_system_.mode4_enable) {
+					screen_mode_ = ScreenMode::SMSMode4;
+					mode_timing_.maximum_visible_sprites = 8;
+					return;
+				}
 			}
 
 			mode_timing_.maximum_visible_sprites = 4;
diff --git a/Machines/ColecoVision/ColecoVision.cpp b/Machines/ColecoVision/ColecoVision.cpp
index 1b6cec505..8349bbef6 100644
--- a/Machines/ColecoVision/ColecoVision.cpp
+++ b/Machines/ColecoVision/ColecoVision.cpp
@@ -117,7 +117,6 @@ class ConcreteMachine:
 	public:
 		ConcreteMachine(const Analyser::Static::Target &target, const ROMMachine::ROMFetcher &rom_fetcher) :
 			z80_(*this),
-			vdp_(TI::TMS::TMS9918A),
 			sn76489_(TI::SN76489::Personality::SN76489, audio_queue_, sn76489_divider),
 			ay_(GI::AY38910::Personality::AY38910, audio_queue_),
 			mixer_(sn76489_, ay_),
diff --git a/Machines/MSX/MSX.cpp b/Machines/MSX/MSX.cpp
index 16752fdcf..6bc06bda0 100644
--- a/Machines/MSX/MSX.cpp
+++ b/Machines/MSX/MSX.cpp
@@ -146,7 +146,6 @@ class ConcreteMachine:
 
 		ConcreteMachine(const Target &target, const ROMMachine::ROMFetcher &rom_fetcher):
 			z80_(*this),
-			vdp_(TI::TMS::TMS9918A),
 			i8255_(i8255_port_handler_),
 			ay_(GI::AY38910::Personality::AY38910, audio_queue_),
 			audio_toggle_(audio_queue_),
diff --git a/Machines/MasterSystem/MasterSystem.cpp b/Machines/MasterSystem/MasterSystem.cpp
index 5b233b7a2..c8db0256a 100644
--- a/Machines/MasterSystem/MasterSystem.cpp
+++ b/Machines/MasterSystem/MasterSystem.cpp
@@ -94,7 +94,6 @@ class ConcreteMachine:
 			region_(target.region),
 			paging_scheme_(target.paging_scheme),
 			z80_(*this),
-			vdp_(tms_personality_for_model(target.model)),
 			sn76489_(
 				(target.model == Target::Model::SG1000) ? TI::SN76489::Personality::SN76489 : TI::SN76489::Personality::SMS,
 				audio_queue_,
@@ -486,7 +485,7 @@ class ConcreteMachine:
 		const Target::Region region_;
 		const Target::PagingScheme paging_scheme_;
 		CPU::Z80::Processor<ConcreteMachine, false, false> z80_;
-		JustInTimeActor<TI::TMS::TMS9918<TI::TMS::Personality::SMSVDP>> vdp_;	// TODO.
+		JustInTimeActor<TI::TMS::TMS9918<TI::TMS::Personality::SMSVDP>> vdp_;	// TODO: use tms_personality_for_model
 
 		Concurrency::AsyncTaskQueue<false> audio_queue_;
 		TI::SN76489 sn76489_;