diff --git a/src/mame/miltonbradley/vectrex_v.cpp b/src/mame/miltonbradley/vectrex_v.cpp
index 4e84ca7c..1d936d24 100644
--- a/src/mame/miltonbradley/vectrex_v.cpp
+++ b/src/mame/miltonbradley/vectrex_v.cpp
@@ -7,6 +7,10 @@
 #include "cpu/m6809/m6809.h"
 
 
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#endif
+
 #define ANALOG_DELAY 8500
 
 #define INT_PER_CLOCK 550
@@ -34,6 +38,49 @@ enum {
 	A_Y
 };
 
+/*********************************************************************
+
+   Web player
+
+   The web player draws the beam itself in WebGL, and MAME renders no
+   picture. MAME's own list holds one T2 period of points, which is
+   only part of a frame when a game overruns T2 or uses T2 as a clock.
+   The player needs every point, once, in order, with the time in
+   microseconds the beam took to reach it: light depends on beam
+   speed. A point with z < 0
+   marks a frame boundary: the program reached the address given to
+   vectrex_web_frame_pc. Games with no recalibrate in their frame loop
+   use it. The player finds other games' frames from the beam.
+
+*********************************************************************/
+
+#ifdef __EMSCRIPTEN__
+namespace {
+	constexpr uint32_t WEB_RING_SIZE = 1 << 17;
+	constexpr double WEB_MIN_FRAME = 0.005; // seconds
+	struct web_point { float x, y, z, us; };
+	web_point s_web_ring[WEB_RING_SIZE];
+	uint32_t s_web_head = 0;
+	double s_web_last_mark = 0.0;
+	uint32_t s_web_frame_pc = 0xffffffff;
+	memory_passthrough_handler s_web_tap;
+
+	inline void web_push(float x, float y, float z, float us)
+	{
+		s_web_ring[s_web_head] = web_point{ x, y, z, us };
+		s_web_head = (s_web_head + 1) & (WEB_RING_SIZE - 1);
+	}
+}
+
+extern "C" {
+	EMSCRIPTEN_KEEPALIVE void *vectrex_web_ring() { return s_web_ring; }
+	EMSCRIPTEN_KEEPALIVE uint32_t vectrex_web_head() { return s_web_head; }
+	EMSCRIPTEN_KEEPALIVE uint32_t vectrex_web_size() { return WEB_RING_SIZE; }
+	EMSCRIPTEN_KEEPALIVE void vectrex_web_frame_pc(uint32_t pc) { s_web_frame_pc = pc; }
+}
+#endif
+
+
 /*********************************************************************
 
    Lightpen
@@ -123,6 +170,10 @@ uint32_t vectrex_base_state::screen_update(screen_device &screen, bitmap_rgb32 &
 {
 	screen_configuration();
 
+#ifdef __EMSCRIPTEN__
+	return 0;
+#endif
+
 	/* start black */
 	m_vector->add_point(m_points[m_display_start].x,
 						m_points[m_display_start].y,
@@ -160,6 +211,11 @@ void vectrex_base_state::add_point(int x, int y, rgb_t color, int intensity)
 	newpoint->y = y;
 	newpoint->col = color;
 	newpoint->intensity = intensity;
+
+#ifdef __EMSCRIPTEN__
+	web_push(x / 65536.0f, y / 65536.0f, float(intensity),
+		float((machine().time() - m_vector_start_time).as_double() * 1e6));
+#endif
 }
 
 
@@ -244,6 +300,20 @@ void vectrex_base_state::video_start()
 	std::fill(std::begin(m_analog), std::end(m_analog), 0);
 	m_point_index = 0;
 	m_lightpen_down = 0;
+
+#ifdef __EMSCRIPTEN__
+	if (s_web_frame_pc != 0xffffffff)
+		s_web_tap = m_maincpu->space(AS_PROGRAM).install_read_tap(s_web_frame_pc, s_web_frame_pc, "web_frame",
+			[this] (offs_t, u8 &, u8)
+			{
+				const double now = machine().time().as_double();
+				if (now - s_web_last_mark >= WEB_MIN_FRAME)
+				{
+					s_web_last_mark = now;
+					web_push(0.0f, 0.0f, -1.0f, 0.0f);
+				}
+			});
+#endif
 }
 
 void vectrex_state::video_start()