diff --git a/BizHawk.Emulation.Common/Database/FirmwareDatabase.cs b/BizHawk.Emulation.Common/Database/FirmwareDatabase.cs
index 4611f68db0..06282b6579 100644
--- a/BizHawk.Emulation.Common/Database/FirmwareDatabase.cs
+++ b/BizHawk.Emulation.Common/Database/FirmwareDatabase.cs
@@ -112,6 +112,11 @@ namespace BizHawk.Emulation.Common
 			Option("GEN", "CD_BIOS_US", us_scd1_9210);
 			Option("GEN", "CD_BIOS_US", us_scd2_9303);
 
+			FirmwareAndOption("dbebd76a448447cb6e524ac3cb0fd19fc065d944", 256, "32X", "G", "32X_G_BIOS.BIN", "32x 68k BIOS");
+			FirmwareAndOption("1e5b0b2441a4979b6966d942b20cc76c413b8c5e", 2048, "32X", "M", "32X_M_BIOS.BIN", "32x SH2 MASTER BIOS");
+			FirmwareAndOption("4103668c1bbd66c5e24558e73d4f3f92061a109a", 1024, "32X", "S", "32X_S_BIOS.BIN", "32x SH2 SLAVE BIOS");
+
+
 			// SMS
 			var sms_us_13 = File("C315672807D8DDB8D91443729405C766DD95CAE7", 8192, "sms_us_1.3.sms", "SMS BIOS 1.3 (USA, Europe)");
 			var sms_jp_21 = File("A8C1B39A2E41137835EDA6A5DE6D46DD9FADBAF2", 8192, "sms_jp_2.1.sms", "SMS BIOS 2.1 (Japan)");
diff --git a/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/PicoDrive.cs b/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/PicoDrive.cs
index 2bf854b7cb..4996ef7671 100644
--- a/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/PicoDrive.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Sega/PicoDrive/PicoDrive.cs
@@ -15,7 +15,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.PicoDrive
 		private LibPicoDrive _core;
 
 		[CoreConstructor("GEN")]
-		public PicoDrive(CoreComm comm, byte[] rom)
+		public PicoDrive(CoreComm comm, byte[] rom, bool deterministic)
 			: base(comm, new Configuration
 			{
 				MaxSamples = 2048,
@@ -26,6 +26,14 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.PicoDrive
 				SystemId = "GEN"
 			})
 		{
+			var biosg = comm.CoreFileProvider.GetFirmware("32X", "G", false);
+			var biosm = comm.CoreFileProvider.GetFirmware("32X", "M", false);
+			var bioss = comm.CoreFileProvider.GetFirmware("32X", "S", false);
+			var has32xBios = biosg != null && biosm != null && bioss != null;
+			if (deterministic && !has32xBios)
+				throw new InvalidOperationException("32X BIOS files are required for deterministic mode");
+			deterministic |= has32xBios;
+
 			_core = PreInit<LibPicoDrive>(new PeRunnerOptions
 			{
 				Filename = "picodrive.wbx",
@@ -36,12 +44,29 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.PicoDrive
 				PlainHeapSizeKB = 4096,
 			});
 
+			if (has32xBios)
+			{
+				_exe.AddReadonlyFile(biosg, "32x.g");
+				_exe.AddReadonlyFile(biosm, "32x.m");
+				_exe.AddReadonlyFile(bioss, "32x.s");
+				Console.WriteLine("Using supplied 32x BIOS files");
+			}
 			_exe.AddReadonlyFile(rom, "romfile.md");
+
 			if (!_core.Init())
 				throw new InvalidOperationException("Core rejected the rom!");
+
 			_exe.RemoveReadonlyFile("romfile.md");
+			if (has32xBios)
+			{
+				_exe.RemoveReadonlyFile("32x.g");
+				_exe.RemoveReadonlyFile("32x.m");
+				_exe.RemoveReadonlyFile("32x.s");
+			}
+
 			PostInit();
 			ControllerDefinition = PicoDriveController;
+			DeterministicEmulation = deterministic;
 		}
 
 		public static readonly ControllerDefinition PicoDriveController = new ControllerDefinition
diff --git a/waterbox/picodrive/bizhawk.c b/waterbox/picodrive/bizhawk.c
index 3ed9b6d5c0..f07bb09850 100644
--- a/waterbox/picodrive/bizhawk.c
+++ b/waterbox/picodrive/bizhawk.c
@@ -97,8 +97,26 @@ int mp3_get_bitrate(void *f, int size) { return 0; }
 void mp3_start_play(void *f, int pos) {}
 void mp3_update(int *buffer, int length, int stereo) {}
 
+static const uint8_t* TryLoadBios(const char* name)
+{
+	FILE *f = fopen(name, "rb");
+	if (!f)
+		return NULL;
+	fseek(f, 0, SEEK_END);
+	int size = ftell(f);
+	uint8_t* ret = alloc_sealed(size);
+	fseek(f, 0, SEEK_SET);
+	fread(ret, 1, size, f);
+	fclose(f);
+	return ret;
+}
+
 ECL_EXPORT int Init(void)
 {
+	p32x_bios_g = TryLoadBios("32x.g");
+	p32x_bios_m = TryLoadBios("32x.m");
+	p32x_bios_s = TryLoadBios("32x.s");
+
 	PicoOpt = POPT_EN_FM | POPT_EN_PSG | POPT_EN_Z80 | POPT_EN_STEREO | POPT_ACC_SPRITES | POPT_DIS_32C_BORDER | POPT_EN_MCD_PCM | POPT_EN_MCD_CDDA | POPT_EN_MCD_GFX | POPT_EN_32X | POPT_EN_PWM;
 
 	PicoInit();
diff --git a/waterbox/picodrive/pico/32x/memory.c b/waterbox/picodrive/pico/32x/memory.c
index d2541c4b56..34c736647e 100644
--- a/waterbox/picodrive/pico/32x/memory.c
+++ b/waterbox/picodrive/pico/32x/memory.c
@@ -43,7 +43,7 @@
 
 static const char str_mars[] = "MARS";
 
-void *p32x_bios_g, *p32x_bios_m, *p32x_bios_s;
+const void *p32x_bios_g, *p32x_bios_m, *p32x_bios_s;
 struct Pico32xMem *Pico32xMem;
 
 static void bank_switch(int b);
diff --git a/waterbox/picodrive/pico/pico.h b/waterbox/picodrive/pico/pico.h
index b15f67672e..818a6af33c 100644
--- a/waterbox/picodrive/pico/pico.h
+++ b/waterbox/picodrive/pico/pico.h
@@ -32,7 +32,7 @@ extern void emu_32x_startup(void);
 
 // optional 32X BIOS, should be left NULL if not used
 // must be 256, 2048, 1024 bytes
-extern void *p32x_bios_g, *p32x_bios_m, *p32x_bios_s;
+extern const void *p32x_bios_g, *p32x_bios_m, *p32x_bios_s;
 
 // Pico.c
 #define POPT_EN_FM          (1<< 0) // 00 000x