diff --git a/BizHawk.Emulation/BizHawk.Emulation.csproj b/BizHawk.Emulation/BizHawk.Emulation.csproj
index e5c1576343..cda43bc45a 100644
--- a/BizHawk.Emulation/BizHawk.Emulation.csproj
+++ b/BizHawk.Emulation/BizHawk.Emulation.csproj
@@ -157,6 +157,7 @@
+
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper203.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper203.cs
new file mode 100644
index 0000000000..0481fa5855
--- /dev/null
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper203.cs
@@ -0,0 +1,95 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Consoles.Nintendo
+{
+ class Mapper203 : NES.NESBoardBase
+ {
+ /*
+ Here are Disch's original notes:
+ ========================
+ = Mapper 203 =
+ ========================
+
+ Example Games:
+ --------------------------
+ 35-in-1
+
+
+ Registers:
+ ---------------------------
+
+
+ $8000-FFFF: [PPPP PPCC]
+ P = PRG Reg
+ C = CHR Reg
+
+
+ CHR Setup:
+ ---------------------------
+
+ $0000 $0400 $0800 $0C00 $1000 $1400 $1800 $1C00
+ +---------------------------------------------------------------+
+ | $8000 |
+ +---------------------------------------------------------------+
+
+
+ PRG Setup:
+ ---------------------------
+
+ $8000 $A000 $C000 $E000
+ +---------------+---------------+
+ | $8000 | $8000 |
+ +---------------+---------------+
+ */
+
+ int prg_reg_16k, chr_reg_8k;
+ int prg_bank_mask_16k;
+ int chr_bank_mask_8k;
+
+ public override bool Configure(NES.EDetectionOrigin origin)
+ {
+ switch (Cart.board_type)
+ {
+ case "MAPPER203":
+ break;
+ default:
+ return false;
+ }
+
+ prg_bank_mask_16k = Cart.prg_size / 16 - 1;
+ chr_bank_mask_8k = Cart.chr_size / 8 - 1;
+
+ return true;
+ }
+
+ public override void SyncState(Serializer ser)
+ {
+ ser.Sync("prg_reg_16k", ref prg_reg_16k);
+ ser.Sync("chr_reg_8k", ref chr_reg_8k);
+ base.SyncState(ser);
+ }
+
+ public override void WritePRG(int addr, byte value)
+ {
+ prg_reg_16k = (value >> 2) & prg_bank_mask_16k;
+ chr_reg_8k = (value & 0x03) & chr_bank_mask_8k;
+ }
+
+ public override byte ReadPRG(int addr)
+ {
+ return ROM[(prg_reg_16k * 0x4000) + (addr & 0x3FFF)];
+ }
+
+ public override byte ReadPPU(int addr)
+ {
+ if (addr < 0x2000)
+ {
+ return VROM[(chr_reg_8k * 0x2000) + addr];
+ }
+ return base.ReadPPU(addr);
+ }
+ }
+}
diff --git a/BizHawk.MultiClient/output/gamedb.txt b/BizHawk.MultiClient/output/gamedb.txt
index e61361ea95..9f93c06914 100644
--- a/BizHawk.MultiClient/output/gamedb.txt
+++ b/BizHawk.MultiClient/output/gamedb.txt
@@ -126,6 +126,9 @@ sha1:977286FDC76C34A618E2A2D0270641BC36CFE89C Nintendo World Championships 1990
sha1:EC652EE1660E527098102E26A36A8B9B7BB3943F Castlevania (Konami Collection 2002) NES board=NES-UNROM;PRG=128;WRAM=0;VRAM=8;PAD_H=1
sha1:B5C4E5E858113F5AA5E063BC79A12D7F6B856E6C Contra (Konami Collection 2002) NES board=NES-UNROM;PRG=128;WRAM=0;VRAM=8;PAD_H=1
+;multi-cart crap
+sha1:B6D1C372A38D196112AA98905C709AD844BD6627 Super 35-in-1 (6-in-1 VT5201) NES board=MAPPER203;PRG=128;CHR=64
+
;chinese shit
sha1:BFA31777E077E64AF0E274B5A22B57C6765D36E1 Fan Kong Jing Ying (Unl) (Ch) NES board=MAPPER241;MIR=H
;;;;;;;;;;;;;;;;;;;-----------------------------------------------------------------------