diff --git a/src/engine/platform/pcmdac.cpp b/src/engine/platform/pcmdac.cpp
index 314ba7dd1..213cb85a3 100644
--- a/src/engine/platform/pcmdac.cpp
+++ b/src/engine/platform/pcmdac.cpp
@@ -50,12 +50,10 @@ void DivPlatformPCMDAC::acquire(short* bufL, short* bufR, size_t start, size_t l
       } else {
         DivSample* s=parent->getSample(chan.sample);
         if (s->samples>0) {
-          if (chan.audPos>=s->samples) {
-            if (s->loopStart>=0 && s->loopStart<(int)s->samples) {
-              chan.audPos=s->loopStart;
-            } else {
-              chan.sample=-1;
-            }
+          if (s->isLoopable() && chan.audPos>=s->getEndPosition()) {
+            chan.audPos=s->loopStart;
+          } else if (chan.audPos>=s->samples) {
+            chan.sample=-1;
           }
           if (chan.audPos<s->samples) {
             output=s->data16[chan.audPos];
diff --git a/src/gui/presets.cpp b/src/gui/presets.cpp
index 3774f232c..ef2236223 100644
--- a/src/gui/presets.cpp
+++ b/src/gui/presets.cpp
@@ -1241,6 +1241,15 @@ void FurnaceGUI::initSystemPresets() {
       0
     }
   ));
+  cat.systems.push_back(FurnaceGUISysDef(
+    "Williams/Midway Y/T unit w/ADPCM sound board", {
+      // ADPCM sound board
+      DIV_SYSTEM_YM2151, 64, 0, 0,
+      DIV_SYSTEM_PCM_DAC, 64, 0, 15624|(7<<16), // variable via OPM timer?
+      DIV_SYSTEM_MSM6295, 64, 0, 0,
+      0
+    }
+  ));
   cat.systems.push_back(FurnaceGUISysDef(
     "Konami Gyruss", {
       DIV_SYSTEM_AY8910, 64, 0, 0,
@@ -1261,6 +1270,34 @@ void FurnaceGUI::initSystemPresets() {
       0
     }
   ));
+  cat.systems.push_back(FurnaceGUISysDef(
+    "Konami Battlantis", {
+      DIV_SYSTEM_OPL2, 64, 0, 3, // 3MHz
+      DIV_SYSTEM_OPL2, 64, 0, 3, // ""
+      0
+    }
+  ));
+  cat.systems.push_back(FurnaceGUISysDef(
+    "Konami Battlantis (drums mode on first OPL2)", {
+      DIV_SYSTEM_OPL2_DRUMS, 64, 0, 3, // 3MHz
+      DIV_SYSTEM_OPL2, 64, 0, 3, // ""
+      0
+    }
+  ));
+  cat.systems.push_back(FurnaceGUISysDef(
+    "Konami Battlantis (drums mode on second OPL2)", {
+      DIV_SYSTEM_OPL2, 64, 0, 3, // 3MHz
+      DIV_SYSTEM_OPL2_DRUMS, 64, 0, 3, // ""
+      0
+    }
+  ));
+  cat.systems.push_back(FurnaceGUISysDef(
+    "Konami Battlantis (drums mode on both OPL2s)", {
+      DIV_SYSTEM_OPL2_DRUMS, 64, 0, 3, // 3MHz
+      DIV_SYSTEM_OPL2_DRUMS, 64, 0, 3, // ""
+      0
+    }
+  ));
   cat.systems.push_back(FurnaceGUISysDef(
     "Konami Hexion", {
       DIV_SYSTEM_SCC, 64, 0, 2, // 1.5MHz (3MHz input)
@@ -1326,6 +1363,13 @@ void FurnaceGUI::initSystemPresets() {
       0
     }
   ));
+  cat.systems.push_back(FurnaceGUISysDef(
+    "Sega System 24", {
+      DIV_SYSTEM_YM2151, 64, 0, 2, // 4MHz
+      DIV_SYSTEM_PCM_DAC, 64, 0, 61499|(7<<16), // software controlled, variable rate via configurable timers
+      0
+    }
+  ));
   cat.systems.push_back(FurnaceGUISysDef(
     "Sega System 18", {
       DIV_SYSTEM_YM2612, 64, 0, 2, // discrete 8MHz YM3438
@@ -1863,7 +1907,7 @@ void FurnaceGUI::initSystemPresets() {
     "Alpha denshi Alpha-68K", {
       DIV_SYSTEM_OPN, 64, 0, 3, // 3MHz
       DIV_SYSTEM_OPLL, 64, 0, 0, // 3.58MHz
-      // software controlled 8 bit DAC
+      DIV_SYSTEM_PCM_DAC, 64, 0, 7613|(7<<16), // software controlled 8 bit DAC
       0
     }
   ));
@@ -1871,7 +1915,7 @@ void FurnaceGUI::initSystemPresets() {
     "Alpha denshi Alpha-68K (extended channel 3)", {
       DIV_SYSTEM_OPN_EXT, 64, 0, 3, // 3MHz
       DIV_SYSTEM_OPLL, 64, 0, 0, // 3.58MHz
-      // software controlled 8 bit DAC
+      DIV_SYSTEM_PCM_DAC, 64, 0, 7613|(7<<16), // software controlled 8 bit DAC
       0
     }
   ));
@@ -1879,7 +1923,7 @@ void FurnaceGUI::initSystemPresets() {
     "Alpha denshi Alpha-68K (drums mode)", {
       DIV_SYSTEM_OPN, 64, 0, 3, // 3MHz
       DIV_SYSTEM_OPLL_DRUMS, 64, 0, 0, // 3.58MHz
-      // software controlled 8 bit DAC
+      DIV_SYSTEM_PCM_DAC, 64, 0, 7613|(7<<16), // software controlled 8 bit DAC
       0
     }
   ));
@@ -1887,7 +1931,7 @@ void FurnaceGUI::initSystemPresets() {
     "Alpha denshi Alpha-68K (extended channel 3; drums mode)", {
       DIV_SYSTEM_OPN_EXT, 64, 0, 3, // 3MHz
       DIV_SYSTEM_OPLL_DRUMS, 64, 0, 0, // 3.58MHz
-      // software controlled 8 bit DAC
+      DIV_SYSTEM_PCM_DAC, 64, 0, 7613|(7<<16), // software controlled 8 bit DAC
       0
     }
   ));
@@ -1929,10 +1973,27 @@ void FurnaceGUI::initSystemPresets() {
       0
     }
   ));
+  cat.systems.push_back(FurnaceGUISysDef(
+    "Namco System 86", { // without expansion board case; Hopping Mappy, etc
+      DIV_SYSTEM_YM2151, 64, 0, 0,
+      DIV_SYSTEM_NAMCO_CUS30, 64, 0, 0
+      0
+    }
+  ));
+  cat.systems.push_back(FurnaceGUISysDef(
+    "Namco Thunder Ceptor", {
+      DIV_SYSTEM_YM2151, 64, 0, 0,
+      DIV_SYSTEM_NAMCO_CUS30, 64, 0, 0,
+      DIV_SYSTEM_PCM_DAC, 64, 0, 7999|(7<<16), // M65C02 software driven, correct sample rate?
+      0
+    }
+  ));
   cat.systems.push_back(FurnaceGUISysDef(
     "Namco System 1", {
       DIV_SYSTEM_YM2151, 64, 0, 0,
       DIV_SYSTEM_NAMCO_CUS30, 64, 0, 0,
+      DIV_SYSTEM_PCM_DAC, 64, 0, 5999|(7<<16), // sample rate verified from https://github.com/mamedev/mame/blob/master/src/devices/sound/n63701x.cpp
+      DIV_SYSTEM_PCM_DAC, 64, 0, 5999|(7<<16), // ""
       0
     }
   ));
@@ -2045,6 +2106,13 @@ void FurnaceGUI::initSystemPresets() {
       0
     }
   ));
+  cat.systems.push_back(FurnaceGUISysDef(
+    "Irem M72", {
+      DIV_SYSTEM_YM2151, 64, 0, 0,
+      DIV_SYSTEM_PCM_DAC, 64, 0, 7811|(7<<16),
+      0
+    }
+  ));
   sysCategories.push_back(cat);
 
   cat=FurnaceGUISysCategory("DefleMask-compatible","these configurations are compatible with DefleMask.\nselect this if you need to save as .dmf or work with that program.");