diff --git a/CMakeLists.txt b/CMakeLists.txt
index 059154f40..7665e24f0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -455,6 +455,8 @@ src/engine/platform/sound/snes/SPC_DSP.cpp
 
 src/engine/platform/sound/ga20/iremga20.cpp
 
+src/engine/platform/sound/sm8521.c
+
 src/engine/platform/oplAInterface.cpp
 src/engine/platform/ym2608Interface.cpp
 src/engine/platform/ym2610Interface.cpp
@@ -539,6 +541,7 @@ src/engine/platform/rf5c68.cpp
 src/engine/platform/snes.cpp
 src/engine/platform/k007232.cpp
 src/engine/platform/ga20.cpp
+src/engine/platform/sm8521.cpp
 src/engine/platform/pcmdac.cpp
 src/engine/platform/dummy.cpp
 )
diff --git a/src/engine/dispatchContainer.cpp b/src/engine/dispatchContainer.cpp
index 030bab559..fe4f76e25 100644
--- a/src/engine/dispatchContainer.cpp
+++ b/src/engine/dispatchContainer.cpp
@@ -75,6 +75,7 @@
 #include "platform/vb.h"
 #include "platform/k007232.h"
 #include "platform/ga20.h"
+#include "platform/sm8521.h"
 #include "platform/pcmdac.h"
 #include "platform/dummy.h"
 #include "../ta-log.h"
@@ -489,6 +490,9 @@ void DivDispatchContainer::init(DivSystem sys, DivEngine* eng, int chanCount, do
     case DIV_SYSTEM_GA20:
       dispatch=new DivPlatformGA20;
       break;
+    case DIV_SYSTEM_SM8521:
+      dispatch=new DivPlatformSM8521;
+      break;
     case DIV_SYSTEM_PCM_DAC:
       dispatch=new DivPlatformPCMDAC;
       break;
diff --git a/src/engine/platform/sm8521.cpp b/src/engine/platform/sm8521.cpp
index ad9789087..db2584c14 100644
--- a/src/engine/platform/sm8521.cpp
+++ b/src/engine/platform/sm8521.cpp
@@ -144,10 +144,8 @@ void DivPlatformSM8521::tick(bool sysTick) {
       rWrite(freqMap[i][1],chan[i].freq&0xff);
       const unsigned char temp=regPool[0x40];
       if (chan[i].keyOn) {
-        rWrite(0x40,temp|(1<<i));
       }
       if (chan[i].keyOff) {
-        rWrite(0x40,temp&~(1<<i));
       }
       if (chan[i].keyOn) chan[i].keyOn=false;
       if (chan[i].keyOff) chan[i].keyOff=false;
@@ -171,6 +169,9 @@ int DivPlatformSM8521::dispatch(DivCommand c) {
       if (!parent->song.brokenOutVol && !chan[c.chan].std.vol.will) {
         chan[c.chan].outVol=chan[c.chan].vol;
       }
+      if (!isMuted[c.chan]) {
+        rWrite(0x40,regPool[0x40]|0x80|(1<<c.chan));
+      }
       if (chan[c.chan].wave<0) {
         chan[c.chan].wave=0;
         chan[c.chan].ws.changeWave1(chan[c.chan].wave);
@@ -186,6 +187,7 @@ int DivPlatformSM8521::dispatch(DivCommand c) {
       chan[c.chan].active=false;
       chan[c.chan].keyOff=true;
       chan[c.chan].macroInit(NULL);
+      rWrite(0x40,regPool[0x40]&~(1<<c.chan));
       break;
     case DIV_CMD_NOTE_OFF_ENV:
     case DIV_CMD_ENV_RELEASE:
@@ -279,6 +281,11 @@ int DivPlatformSM8521::dispatch(DivCommand c) {
 void DivPlatformSM8521::muteChannel(int ch, bool mute) {
   isMuted[ch]=mute;
   chan[ch].volumeChanged=true;
+  if (mute) {
+    rWrite(0x40,regPool[0x40]&~(1<<ch));
+  } else if (chan[ch].active) {
+    rWrite(0x40,regPool[0x40]|0x80|(1<<ch));
+  }
 }
 
 void DivPlatformSM8521::forceIns() {
@@ -322,7 +329,7 @@ void DivPlatformSM8521::reset() {
     addWrite(0xffffffff,0);
   }
   sm8521_reset(&sm8521);
-  sm8521_write(&sm8521,0x40,0x80); // initialize SGC
+  rWrite(0x40,0x80); // initialize SGC
 }
 
 int DivPlatformSM8521::getOutputCount() {
diff --git a/src/engine/platform/sm8521.h b/src/engine/platform/sm8521.h
index 4b9318c4f..b0a119fb5 100644
--- a/src/engine/platform/sm8521.h
+++ b/src/engine/platform/sm8521.h
@@ -17,8 +17,8 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#ifndef _NAMCOWSG_H
-#define _NAMCOWSG_H
+#ifndef _SM8521_H
+#define _SM8521_H
 
 #include "../dispatch.h"
 #include <queue>
@@ -26,8 +26,8 @@
 #include "sound/sm8521.h"
 
 class DivPlatformSM8521: public DivDispatch {
-
   const unsigned char volMap[3]={0x42,0x44,0x4a};
+
   const unsigned char freqMap[3][2]={{0x46,0x47},{0x48,0x49},{0x4c,0x4d}};
 
   struct Channel: public SharedChannel<signed char> {
@@ -36,7 +36,7 @@ class DivPlatformSM8521: public DivDispatch {
     bool volumeChanged;
     DivWaveSynth ws;
     Channel():
-      SharedChannel<signed char>(15),
+      SharedChannel<signed char>(31),
       antiClickPeriodCount(0),
       antiClickWavePos(0),
       wave(-1),
diff --git a/src/engine/platform/sound/sm8521.c b/src/engine/platform/sound/sm8521.c
new file mode 100644
index 000000000..831dd6aa6
--- /dev/null
+++ b/src/engine/platform/sound/sm8521.c
@@ -0,0 +1,235 @@
+/*
+
+============================================================================
+
+SM8521 sound emulator
+by cam900
+
+This file is licensed under zlib license.
+
+============================================================================
+
+zlib License
+
+(C) 2022-present cam900 and contributors
+
+This software is provided 'as-is', without any express or implied
+warranty.  In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not
+   claim that you wrote the original software. If you use this software
+   in a product, an acknowledgment in the product documentation would be
+   appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be
+   misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+
+============================================================================
+
+TODO:
+- needs hardware test
+
+*/
+
+#include "sm8521.h"
+#include <stdlib.h>
+
+enum sm8521_sgc
+{
+	SM8521_SGC_SONDOUT = (1 << 7),
+	SM8521_SGC_DIROUT = (1 << 3),
+	SM8521_SGC_SG2OUT = (1 << 2),
+	SM8521_SGC_SG1OUT = (1 << 1),
+	SM8521_SGC_SG0OUT = (1 << 0)
+};
+
+void sm8521_sg_wave_tick(struct sm8521_wave_t *sg, const int cycle)
+{
+	sg->base.counter += cycle;
+	while (sg->base.counter >= (sg->base.t + 1))
+	{
+		sg->addr++;
+		sg->base.counter -= (sg->base.t + 1);
+	}
+	int wave = (sg->wave[(sg->addr >> 1) & 0xf] >> ((sg->addr & 1) << 2)) & 0xf;
+	if (wave & 0x8)
+	{
+		wave = -(0x8 - (wave & 0x7));
+	}
+	sg->base.out = (wave * sg->base.level) >> 1; // scale out to 8bit
+}
+
+void sm8521_noise_tick(struct sm8521_noise_t *noise, const int cycle)
+{
+	noise->base.counter += cycle;
+	while (noise->base.counter >= (noise->base.t + 1))
+	{
+		noise->lfsr = rand() & 0x1; // unknown algorithm
+		noise->base.counter -= (noise->base.t + 1);
+	}
+	noise->base.out = (((noise->lfsr & 0x1) ? 7 : -8) * noise->base.level) >> 1; // scale out to 8bit
+}
+
+void sm8521_sound_tick(struct sm8521_t *sm8521, const int cycle)
+{
+	int out = 0;
+	if (sm8521->sgc & SM8521_SGC_SONDOUT)
+	{
+		if (sm8521->sgc & SM8521_SGC_DIROUT)
+		{
+			out = sm8521->sgda - 0x80;
+		}
+		else
+		{
+			if (sm8521->sgc & SM8521_SGC_SG0OUT)
+			{
+				sm8521_sg_wave_tick(&sm8521->sg[0], cycle);
+				out += sm8521->sg[0].base.out;
+			}
+			if (sm8521->sgc & SM8521_SGC_SG1OUT)
+			{
+				sm8521_sg_wave_tick(&sm8521->sg[1], cycle);
+				out += sm8521->sg[1].base.out;
+			}
+			if (sm8521->sgc & SM8521_SGC_SG2OUT)
+			{
+				sm8521_noise_tick(&sm8521->noise, cycle);
+				out += sm8521->noise.base.out;
+			}
+			out = (out < -0x80) ? -0x80 : ((out > 0x7f) ? 0x7f : out); // clamp
+		}
+	}
+	sm8521->out = out;
+}
+
+void sm8521_reset(struct sm8521_t *sm8521)
+{
+	for (int i = 0; i < 2; i++)
+	{
+		sm8521->sg[i].base.t = 0;
+		sm8521->sg[i].base.level = 0;
+		sm8521->sg[i].base.out = 0;
+		sm8521->sg[i].base.counter = 0;
+		sm8521->sg[i].addr = 0;
+		for (int j = 0; j < 16; j++)
+		{
+			sm8521->sg[i].wave[j] = 0;
+		}
+	}
+	sm8521->noise.base.t = 0;
+	sm8521->noise.base.level = 0;
+	sm8521->noise.base.out = 0;
+	sm8521->noise.base.counter = 0;
+	sm8521->noise.lfsr = 0;
+	sm8521->out = 0;
+	sm8521->sgda = 0;
+	sm8521->sgc = 0;
+}
+
+unsigned char sm8521_read(struct sm8521_t *sm8521, const unsigned char a)
+{
+	if ((a & 0xe0) == 0x60)
+	{
+		if ((a & 0x10) && (!(sm8521->sgc & SM8521_SGC_SG1OUT))) // 0x70-0x7f SG1W0-15
+		{
+			return sm8521->sg[1].wave[a & 0xf];
+		}
+		else if ((!(a & 0x10)) && (!(sm8521->sgc & SM8521_SGC_SG0OUT))) // 0x60-0x6f SG0W0-15
+		{
+			return sm8521->sg[0].wave[a & 0xf];
+		}
+		return 0;
+	}
+	switch (a)
+	{
+		case 0x40: // SGC
+			return sm8521->sgc;
+			break;
+		case 0x42: // SG0L
+			return sm8521->sg[0].base.level & 0x1f;
+			break;
+		case 0x44: // SG1L
+			return sm8521->sg[1].base.level & 0x1f;
+			break;
+		case 0x46: // SG0TH
+			return (sm8521->sg[0].base.t >> 8) & 0xf;
+			break;
+		case 0x47: // SG0TL
+			return sm8521->sg[0].base.t & 0xff;
+			break;
+		case 0x48: // SG1TH
+			return (sm8521->sg[1].base.t >> 8) & 0xf;
+			break;
+		case 0x49: // SG1TL
+			return sm8521->sg[1].base.t & 0x0ff;
+			break;
+		case 0x4a: // SG2L
+			return sm8521->noise.base.level & 0x1f;
+			break;
+		case 0x4c: // SG2TH
+			return (sm8521->noise.base.t >> 8) & 0xf;
+			break;
+		case 0x4d: // SG2TL
+			return sm8521->noise.base.t & 0xff;
+			break;
+		default:
+			return 0;
+			break;
+	}
+}
+void sm8521_write(struct sm8521_t *sm8521, const unsigned char a, const unsigned char d)
+{
+	if ((a & 0xe0) == 0x60)
+	{
+		if ((a & 0x10) && (!(sm8521->sgc & SM8521_SGC_SG1OUT))) // 0x70-0x7f SG1W0-15
+		{
+			sm8521->sg[1].wave[a & 0xf] = d;
+		}
+		else if ((!(a & 0x10)) && (!(sm8521->sgc & SM8521_SGC_SG0OUT))) // 0x60-0x6f SG0W0-15
+		{
+			sm8521->sg[0].wave[a & 0xf] = d;
+		}
+		return;
+	}
+	switch (a)
+	{
+		case 0x40: // SGC
+			sm8521->sgc = d;
+			break;
+		case 0x42: // SG0L
+			sm8521->sg[0].base.level = d & 0x1f;
+			break;
+		case 0x44: // SG1L
+			sm8521->sg[1].base.level = d & 0x1f;
+			break;
+		case 0x46: // SG0TH
+			sm8521->sg[0].base.t = (sm8521->sg[0].base.t & 0x0ff) | ((d << 8) & 0xf00);
+			break;
+		case 0x47: // SG0TL
+			sm8521->sg[0].base.t = (sm8521->sg[0].base.t & 0xf00) | (d & 0x0ff);
+			break;
+		case 0x48: // SG1TH
+			sm8521->sg[1].base.t = (sm8521->sg[1].base.t & 0x0ff) | ((d << 8) & 0xf00);
+			break;
+		case 0x49: // SG1TL
+			sm8521->sg[1].base.t = (sm8521->sg[1].base.t & 0xf00) | (d & 0x0ff);
+			break;
+		case 0x4a: // SG2L
+			sm8521->noise.base.level = d & 0x1f;
+			break;
+		case 0x4c: // SG2TH
+			sm8521->noise.base.t = (sm8521->noise.base.t & 0x0ff) | ((d << 8) & 0xf00);
+			break;
+		case 0x4d: // SG2TL
+			sm8521->noise.base.t = (sm8521->noise.base.t & 0xf00) | (d & 0x0ff);
+			break;
+		case 0x4e: // SGDA
+			sm8521->sgda = d;
+			break;
+	}
+}
diff --git a/src/engine/platform/sound/sm8521.h b/src/engine/platform/sound/sm8521.h
index 24635eb01..6577df004 100644
--- a/src/engine/platform/sound/sm8521.h
+++ b/src/engine/platform/sound/sm8521.h
@@ -36,22 +36,14 @@ TODO:
 
 */
 
-#include <stdlib.h>
+#ifndef _SM8521_EMU_H
+#define _SM8521_EMU_H
 
 #ifdef __cplusplus
 extern "C"
 {
 #endif
 
-enum sm8521_sgc
-{
-	SM8521_SGC_SONDOUT = (1 << 7),
-	SM8521_SGC_DIROUT = (1 << 3),
-	SM8521_SGC_SG2OUT = (1 << 2),
-	SM8521_SGC_SG1OUT = (1 << 1),
-	SM8521_SGC_SG0OUT = (1 << 0)
-};
-
 struct sm8521_sg_t
 {
 	unsigned short t; // Time constant register
@@ -82,192 +74,19 @@ struct sm8521_t
 	unsigned char sgc; // Control register
 };
 
-void sm8521_sg_wave_tick(struct sm8521_wave_t *sg, const int cycle)
-{
-	sg->base.counter += cycle;
-	while (sg->base.counter >= (sg->base.t + 1))
-	{
-		sg->addr++;
-		sg->base.counter -= (sg->base.t + 1);
-	}
-	int wave = (sg->wave[(sg->addr >> 1) & 0xf] >> ((sg->addr & 1) << 2)) & 0xf;
-	if (wave & 0x8)
-	{
-		wave = -(0x8 - (wave & 0x7));
-	}
-	sg->base.out = (wave * sg->base.level) >> 1; // scale out to 8bit
-}
+void sm8521_sg_wave_tick(struct sm8521_wave_t *sg, const int cycle);
 
-void sm8521_noise_tick(struct sm8521_noise_t *noise, const int cycle)
-{
-	noise->base.counter += cycle;
-	while (noise->base.counter >= (noise->base.t + 1))
-	{
-		noise->lfsr = rand() & 0x1; // unknown algorithm
-		noise->base.counter -= (noise->base.t + 1);
-	}
-	noise->base.out = (((noise->lfsr & 0x1) ? 7 : -8) * noise->base.level) >> 1; // scale out to 8bit
-}
+void sm8521_noise_tick(struct sm8521_noise_t *noise, const int cycle);
 
-void sm8521_sound_tick(struct sm8521_t *sm8521, const int cycle)
-{
-	int out = 0;
-	if (sm8521->sgc & SM8521_SGC_SONDOUT)
-	{
-		if (sm8521->sgc & SM8521_SGC_DIROUT)
-		{
-			out = sm8521->sgda - 0x80;
-		}
-		else
-		{
-			if (sm8521->sgc & SM8521_SGC_SG0OUT)
-			{
-				sm8521_sg_wave_tick(&sm8521->sg[0], cycle);
-				out += sm8521->sg[0].base.out;
-			}
-			if (sm8521->sgc & SM8521_SGC_SG1OUT)
-			{
-				sm8521_sg_wave_tick(&sm8521->sg[1], cycle);
-				out += sm8521->sg[1].base.out;
-			}
-			if (sm8521->sgc & SM8521_SGC_SG2OUT)
-			{
-				sm8521_noise_tick(&sm8521->noise, cycle);
-				out += sm8521->noise.base.out;
-			}
-			out = (out < -0x80) ? -0x80 : ((out > 0x7f) ? 0x7f : out); // clamp
-		}
-	}
-	sm8521->out = out;
-}
+void sm8521_sound_tick(struct sm8521_t *sm8521, const int cycle);
 
-void sm8521_reset(struct sm8521_t *sm8521)
-{
-	for (int i = 0; i < 2; i++)
-	{
-		sm8521->sg[i].base.t = 0;
-		sm8521->sg[i].base.level = 0;
-		sm8521->sg[i].base.out = 0;
-		sm8521->sg[i].base.counter = 0;
-		sm8521->sg[i].addr = 0;
-		for (int j = 0; j < 16; j++)
-		{
-			sm8521->sg[i].wave[j] = 0;
-		}
-	}
-	sm8521->noise.base.t = 0;
-	sm8521->noise.base.level = 0;
-	sm8521->noise.base.out = 0;
-	sm8521->noise.base.counter = 0;
-	sm8521->noise.lfsr = 0;
-	sm8521->out = 0;
-	sm8521->sgda = 0;
-	sm8521->sgc = 0;
-}
+void sm8521_reset(struct sm8521_t *sm8521);
 
-unsigned char sm8521_read(struct sm8521_t *sm8521, const unsigned char a)
-{
-	if ((a & 0xe0) == 0x60)
-	{
-		if ((a & 0x10) && (!(sm8521->sgc & SM8521_SGC_SG1OUT))) // 0x70-0x7f SG1W0-15
-		{
-			return sm8521->sg[1].wave[a & 0xf];
-		}
-		else if ((!(a & 0x10)) && (!(sm8521->sgc & SM8521_SGC_SG0OUT))) // 0x60-0x6f SG0W0-15
-		{
-			return sm8521->sg[0].wave[a & 0xf];
-		}
-		return 0;
-	}
-	switch (a)
-	{
-		case 0x40: // SGC
-			return sm8521->sgc;
-			break;
-		case 0x42: // SG0L
-			return sm8521->sg[0].base.level & 0x1f;
-			break;
-		case 0x44: // SG1L
-			return sm8521->sg[1].base.level & 0x1f;
-			break;
-		case 0x46: // SG0TH
-			return (sm8521->sg[0].base.t >> 8) & 0xf;
-			break;
-		case 0x47: // SG0TL
-			return sm8521->sg[0].base.t & 0xff;
-			break;
-		case 0x48: // SG1TH
-			return (sm8521->sg[1].base.t >> 8) & 0xf;
-			break;
-		case 0x49: // SG1TL
-			return sm8521->sg[1].base.t & 0x0ff;
-			break;
-		case 0x4a: // SG2L
-			return sm8521->noise.base.level & 0x1f;
-			break;
-		case 0x4c: // SG2TH
-			return (sm8521->noise.base.t >> 8) & 0xf;
-			break;
-		case 0x4d: // SG2TL
-			return sm8521->noise.base.t & 0xff;
-			break;
-		default:
-			return 0;
-			break;
-	}
-}
-void sm8521_write(struct sm8521_t *sm8521, const unsigned char a, const unsigned char d)
-{
-	if ((a & 0xe0) == 0x60)
-	{
-		if ((a & 0x10) && (!(sm8521->sgc & SM8521_SGC_SG1OUT))) // 0x70-0x7f SG1W0-15
-		{
-			sm8521->sg[1].wave[a & 0xf] = d;
-		}
-		else if ((!(a & 0x10)) && (!(sm8521->sgc & SM8521_SGC_SG0OUT))) // 0x60-0x6f SG0W0-15
-		{
-			sm8521->sg[0].wave[a & 0xf] = d;
-		}
-		return;
-	}
-	switch (a)
-	{
-		case 0x40: // SGC
-			sm8521->sgc = d;
-			break;
-		case 0x42: // SG0L
-			sm8521->sg[0].base.level = d & 0x1f;
-			break;
-		case 0x44: // SG1L
-			sm8521->sg[1].base.level = d & 0x1f;
-			break;
-		case 0x46: // SG0TH
-			sm8521->sg[0].base.t = (sm8521->sg[0].base.t & 0x0ff) | ((d << 8) & 0xf00);
-			break;
-		case 0x47: // SG0TL
-			sm8521->sg[0].base.t = (sm8521->sg[0].base.t & 0xf00) | (d & 0x0ff);
-			break;
-		case 0x48: // SG1TH
-			sm8521->sg[1].base.t = (sm8521->sg[1].base.t & 0x0ff) | ((d << 8) & 0xf00);
-			break;
-		case 0x49: // SG1TL
-			sm8521->sg[1].base.t = (sm8521->sg[1].base.t & 0xf00) | (d & 0x0ff);
-			break;
-		case 0x4a: // SG2L
-			sm8521->noise.base.level = d & 0x1f;
-			break;
-		case 0x4c: // SG2TH
-			sm8521->noise.base.t = (sm8521->noise.base.t & 0x0ff) | ((d << 8) & 0xf00);
-			break;
-		case 0x4d: // SG2TL
-			sm8521->noise.base.t = (sm8521->noise.base.t & 0xf00) | (d & 0x0ff);
-			break;
-		case 0x4e: // SGDA
-			sm8521->sgda = d;
-			break;
-	}
-}
+unsigned char sm8521_read(struct sm8521_t *sm8521, const unsigned char a);
+void sm8521_write(struct sm8521_t *sm8521, const unsigned char a, const unsigned char d);
 
 #ifdef __cplusplus
 } // extern "C"
 #endif
+
+#endif // _SM8521_EMU_H
\ No newline at end of file
diff --git a/src/engine/song.h b/src/engine/song.h
index 72fbea0ef..0cf1f0195 100644
--- a/src/engine/song.h
+++ b/src/engine/song.h
@@ -124,7 +124,8 @@ enum DivSystem {
   DIV_SYSTEM_YM2610_CSM,
   DIV_SYSTEM_YM2610B_CSM,
   DIV_SYSTEM_YM2203_CSM,
-  DIV_SYSTEM_YM2608_CSM
+  DIV_SYSTEM_YM2608_CSM,
+  DIV_SYSTEM_SM8521
 };
 
 struct DivGroovePattern {
diff --git a/src/engine/sysDef.cpp b/src/engine/sysDef.cpp
index c6368cc84..09cfdc414 100644
--- a/src/engine/sysDef.cpp
+++ b/src/engine/sysDef.cpp
@@ -1822,6 +1822,17 @@ void DivEngine::registerSystems() {
     {DIV_INS_AMIGA, DIV_INS_AMIGA, DIV_INS_AMIGA, DIV_INS_AMIGA}
   );
 
+  sysDefs[DIV_SYSTEM_SM8521]=new DivSysDef(
+    "Sharp SM8521", NULL, 0xc8, 0, 3, false, true, 0, false, 0,
+    "a SoC with wavetable sound hardware",
+    {"Channel 1", "Channel 2", "Noise"},
+    {"CH1", "CH2", "NOI"},
+    {DIV_CH_WAVE, DIV_CH_WAVE, DIV_CH_NOISE},
+    {DIV_INS_NAMCO, DIV_INS_NAMCO, DIV_INS_NAMCO},
+    {},
+    namcoEffectHandlerMap
+  );
+
   sysDefs[DIV_SYSTEM_DUMMY]=new DivSysDef(
     "Dummy System", NULL, 0xfd, 0, 8, false, true, 0, false, 0,
     "this is a system designed for testing purposes.",
diff --git a/src/gui/guiConst.cpp b/src/gui/guiConst.cpp
index be1573778..4997c28fb 100644
--- a/src/gui/guiConst.cpp
+++ b/src/gui/guiConst.cpp
@@ -998,6 +998,7 @@ const int availableSystems[]={
   DIV_SYSTEM_MSM5232,
   DIV_SYSTEM_K007232,
   DIV_SYSTEM_GA20,
+  DIV_SYSTEM_SM8521,
   DIV_SYSTEM_PCM_DAC,
   DIV_SYSTEM_PONG,
   0 // don't remove this last one!
@@ -1084,6 +1085,7 @@ const int chipsSpecial[]={
   DIV_SYSTEM_PET,
   DIV_SYSTEM_VRC6,
   DIV_SYSTEM_MMC5,
+  DIV_SYSTEM_SM8521,
   0 // don't remove this last one!
 };
 
diff --git a/src/gui/presets.cpp b/src/gui/presets.cpp
index 579cf2d38..3027be8c3 100644
--- a/src/gui/presets.cpp
+++ b/src/gui/presets.cpp
@@ -2575,6 +2575,11 @@ void FurnaceGUI::initSystemPresets() {
       CH(DIV_SYSTEM_SFX_BEEPER, 1.0f, 0, "")
     }
   );
+  ENTRY(
+    "Sharp SM8521", {
+      CH(DIV_SYSTEM_SM8521, 1.0f, 0, "")
+    }
+  );
   if (settings.hiddenSystems) {
     ENTRY(
       "Dummy System", {