diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/HKROM.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/HKROM.cs
index 7c12597f57..adc343eda7 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/HKROM.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/HKROM.cs
@@ -25,11 +25,16 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 					Cart.wram_size = 1; //1K of wram is in the mmc6
 					Cart.wram_battery = true; //and its battery backed.
 					break;
+				case "MAPPER004_MMC6":
+					Cart.wram_size = 1; //1K of wram is in the mmc6
+					Cart.wram_battery = true; //and its battery backed.
+					break;
 				default:
 					return false;
 			}
 
 			BaseSetup();
+			mmc3.MMC3Type = MMC3.EMMC3Type.MMC6;
 
 			return true;
 		}
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3_family.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3_family.cs
index bcd1043216..6eb2e00b31 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3_family.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3_family.cs
@@ -133,7 +133,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 		//configuration
 		public enum EMMC3Type
 		{
-			None, MMC3A, MMC3BSharp, MMC3BNonSharp, MMC3C
+			None, MMC3A, MMC3BSharp, MMC3BNonSharp, MMC3C, MMC6
 		}
 		EMMC3Type _mmc3type = EMMC3Type.None;
 		public EMMC3Type MMC3Type
@@ -142,7 +142,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			set
 			{
 				_mmc3type = value;
-				oldIrqType = (_mmc3type == EMMC3Type.MMC3A || _mmc3type == EMMC3Type.MMC3BNonSharp);
+				oldIrqType = (_mmc3type == EMMC3Type.MMC3A || _mmc3type == EMMC3Type.MMC3BNonSharp || _mmc3type == EMMC3Type.MMC6);
 			}
 		}
 		bool oldIrqType;
@@ -281,12 +281,12 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			{
 				if (separator_counter > 0)
 				{
-					separator_counter = 12;
+					separator_counter = 15;
 				}
 				else
 				{
-					separator_counter = 12;
-					irq_countdown = 12;
+					separator_counter = 15;
+					irq_countdown = 6;
 				}
 			}
 
diff --git a/BizHawk.MultiClient/output/gamedb.txt b/BizHawk.MultiClient/output/gamedb.txt
index 95dae2eb5d..87f4f1b001 100644
--- a/BizHawk.MultiClient/output/gamedb.txt
+++ b/BizHawk.MultiClient/output/gamedb.txt
@@ -123,6 +123,8 @@ sha1:B5C4E5E858113F5AA5E063BC79A12D7F6B856E6C		Contra (Konami Collection 2002)	N
 ;mmc3 homebrews that need chip specification
 sha1:35C157A921156E47FD3F6573D150F54108D0EDFC		Blargg's 5.MMC3_rev_A.nes	NES		board=MAPPER004;MMC3=MMC3A
 sha1:0E971E2CCAD1DEE51A0C305ED38FAFD2E6CA3B41		Blargg's 6.MMC3_rev_B.nes	NES		board=MAPPER004;MMC3=MMC3B
+sha1:F794FDA12D34E611D58E652319ED583AE61B81E0		Blargg's 6-MMC6.nes	NES		board=MAPPER004_MMC6
+sha1:2F29F3DC724027FAD926BC9D4470A481884E42A5		Blargg's 6-MMC6.nes (newer)	NES		board=MAPPER004_MMC6
 ;;;;;;;;;;;;;;;;;;;-----------------------------------------------------------------------
 
 #include gamedb_neshomebrew.txt