diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Namcot1xx/Mapper088.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Namcot1xx/Mapper088.cs
index d49fe493a7..b81ddcbdd3 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Namcot1xx/Mapper088.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Namcot1xx/Mapper088.cs
@@ -14,16 +14,15 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 	
 	This is the same as Mapper206, with the following exception:
 	CHR support is increased to 128KB by connecting PPU's A12 line to the CHR ROM's A16 line.
-	For example, masking the CHR ROM address output from the mapper by $FFFF, and then OR it with $10000 if the PPU address was >= $1000.
+	For example, mask the CHR ROM 1K bank output from the mapper by $3F, and then OR it with $40 if the PPU address was >= $1000.
 	Consequently, CHR is split into two halves. $0xxx can only have CHR from the first 64K, $1xxx can only have CHR from the second 64K.
-	
 	*/
 
 
 	class Mapper088 : Namcot108Board_Base
 	{
 		//configuration
-		int chr_byte_mask;
+		int chr_bank_mask_1k;
 
 		public override bool Configure(NES.EDetectionOrigin origin)
 		{
@@ -41,19 +40,21 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			BaseSetup();
 			SetMirrorType(EMirrorType.Vertical);
 
-			chr_byte_mask = (Cart.chr_size*1024) - 1;
+			chr_bank_mask_1k = Cart.chr_size - 1;
 
 			return true;
 		}
 
 		int RewireCHR(int addr)
 		{
-			int chrrom_addr = base.MapCHR(addr);
-			chrrom_addr &= 0xFFFF;
+			int bank_1k = mapper.Get_CHRBank_1K(addr);
+			bank_1k &= 0x3F;
 			if (addr >= 0x1000)
-				chrrom_addr |= 0x10000;
-			chrrom_addr &= chr_byte_mask;
-			return chrrom_addr;
+				bank_1k |= 0x40;
+			bank_1k &= chr_bank_mask_1k;
+			int ofs = addr & ((1 << 10) - 1);
+			addr = (bank_1k << 10) + ofs;
+			return addr;
 		}
 
 		public override byte ReadPPU(int addr)