diff --git a/arm7/source/main.c b/arm7/source/main.c
index 16a3d09..31515f7 100644
--- a/arm7/source/main.c
+++ b/arm7/source/main.c
@@ -32,6 +32,8 @@
 
 #include "gba.h"
 
+#define SD_IRQ_STATUS (*(vu32*)0x400481C)
+
 void my_installSystemFIFO(void);
 void my_sdmmc_get_cid(int devicenumber, u32 *cid);
 
@@ -177,9 +179,11 @@ int main() {
 			my_sdmmc_get_cid(true, (u32*)0x2FFD7BC);	// Get eMMC CID
 			*(u32*)(0x2FFFD0C) = 0;
 		}
-		*(u8*)(0x2FFFD08) = ((*(vu32*)(0x400481C) & BIT(3)) || !(*(vu32*)(0x400481C) & BIT(5)));	// Set if there's no SD inserted
 		resyncClock();
 
+		// Send SD status
+		fifoSendValue32(FIFO_USER_04, SD_IRQ_STATUS);
+
 		// Dump EEPROM save
 		if(fifoCheckAddress(FIFO_USER_01)) {
 			switch(fifoGetValue32(FIFO_USER_01)) {
diff --git a/arm7/source/my_sdmmc.c b/arm7/source/my_sdmmc.c
index 8388a9f..a9f1e19 100644
--- a/arm7/source/my_sdmmc.c
+++ b/arm7/source/my_sdmmc.c
@@ -250,26 +250,31 @@ int my_sdmmc_cardinserted() {
 
 
 static bool my_sdmmc_controller_initialised = false;
+static bool my_nand_controller_initialised = false;
 
 //---------------------------------------------------------------------------------
 void my_sdmmc_controller_init( bool force_init ) {
 //---------------------------------------------------------------------------------
 
-    if (!force_init && my_sdmmc_controller_initialised) return;
+    if (!force_init && my_sdmmc_controller_initialised && my_nand_controller_initialised) return;
 
-    deviceSD.isSDHC = 0;
-    deviceSD.SDOPT = 0;
-    deviceSD.res = 0;
-    deviceSD.initarg = 0;
-    deviceSD.clk = 0x80;
-    deviceSD.devicenumber = 0;
+    if(true||!my_sdmmc_controller_initialised) {
+        deviceSD.isSDHC = 0;
+        deviceSD.SDOPT = 0;
+        deviceSD.res = 0;
+        deviceSD.initarg = 0;
+        deviceSD.clk = 0x80;
+        deviceSD.devicenumber = 0;
+    }
 
-    deviceNAND.isSDHC = 0;
-    deviceNAND.SDOPT = 0;
-    deviceNAND.res = 0;
-    deviceNAND.initarg = 1;
-    deviceNAND.clk = 0x80;
-    deviceNAND.devicenumber = 1;
+    if(!my_nand_controller_initialised) {
+        deviceNAND.isSDHC = 0;
+        deviceNAND.SDOPT = 0;
+        deviceNAND.res = 0;
+        deviceNAND.initarg = 1;
+        deviceNAND.clk = 0x80;
+        deviceNAND.devicenumber = 1;
+    }
 
     *(vu16*)(SDMMC_BASE + REG_SDDATACTL32) &= 0xF7FFu;
     *(vu16*)(SDMMC_BASE + REG_SDDATACTL32) &= 0xEFFFu;
@@ -308,6 +313,7 @@ void my_sdmmc_controller_init( bool force_init ) {
     *(vu16*)(SDMMC_BASE + REG_SDSTOP) = 0;
 
     my_sdmmc_controller_initialised = true;
+    my_nand_controller_initialised = true;
 
     my_setTarget(&deviceSD);
 }
@@ -594,7 +600,7 @@ int my_sdmmc_nand_startup() {
 //---------------------------------------------------------------------------------
 int my_sdmmc_sd_startup() {
 //---------------------------------------------------------------------------------
-    my_sdmmc_controller_init(true);
+    my_sdmmc_controller_init(false);
     return my_sdmmc_sdcard_init();
 }
 
@@ -627,6 +633,7 @@ void my_sdmmcValueHandler(u32 value, void* user_data) {
         break;
 
     case SDMMC_SD_STOP:
+        my_sdmmc_controller_initialised = false;
         break;
 
     case SDMMC_NAND_SIZE:
diff --git a/arm9/source/driveMenu.cpp b/arm9/source/driveMenu.cpp
index 4eab364..398c846 100644
--- a/arm9/source/driveMenu.cpp
+++ b/arm9/source/driveMenu.cpp
@@ -35,6 +35,7 @@
 #include "fileOperations.h"
 #include "font.h"
 #include "language.h"
+#include "my_sd.h"
 #include "read_card.h"
 #include "startMenu.h"
 
@@ -84,24 +85,33 @@ void dm_drawTopScreen(void) {
 		switch(dmOperations[i]) {
 			case DriveMenuOperation::sdCard:
 				font->printf(0, i + 1, true, Alignment::left, pal, STR_SDCARD_LABEL.c_str(), sdLabel[0] == 0 ? STR_UNTITLED.c_str() : sdLabel);
+				if(!driveWritable(Drive::sdCard))
+					font->print(-1, i + 1, true, "[R]", Alignment::right, pal);
 				break;
 			case DriveMenuOperation::flashcard:
 				font->printf(0, i + 1, true, Alignment::left, pal, STR_FLASHCARD_LABEL.c_str(), fatLabel[0] == 0 ? STR_UNTITLED.c_str() : fatLabel);
+				if(!driveWritable(Drive::flashcard))
+					font->print(-1, i + 1, true, "[R]", Alignment::right, pal);
 				break;
 			case DriveMenuOperation::ramDrive:
 				font->print(0, i + 1, true, STR_RAMDRIVE_LABEL, Alignment::left, pal);
 				break;
 			case DriveMenuOperation::sysNand:
 				font->print(0, i + 1, true, STR_SYSNAND_LABEL, Alignment::left, pal);
+				if(!driveWritable(Drive::nand))
+					font->print(-1, i + 1, true, "[R]", Alignment::right, pal);
 				break;
 			case DriveMenuOperation::nitroFs:
 				font->print(0, i + 1, true, STR_NITROFS_LABEL, Alignment::left, pal);
+
 				if (!((sdMounted && nitroCurrentDrive == Drive::sdCard)
 				|| (flashcardMounted && nitroCurrentDrive == Drive::flashcard)
 				|| (ramdriveMounted && nitroCurrentDrive == Drive::ramDrive)
 				|| (nandMounted && nitroCurrentDrive == Drive::nand)
 				|| (imgMounted && nitroCurrentDrive == Drive::fatImg)))
 					font->print(-1, i + 1, true, "[x]", Alignment::right, pal);
+				else
+					font->print(-1, i + 1, true, "[R]", Alignment::right, pal);
 				break;
 			case DriveMenuOperation::fatImage:
 				if ((sdMounted && imgCurrentDrive == Drive::sdCard)
@@ -109,6 +119,7 @@ void dm_drawTopScreen(void) {
 				|| (ramdriveMounted && imgCurrentDrive == Drive::ramDrive)
 				|| (nandMounted && imgCurrentDrive == Drive::nand)) {
 					font->printf(0, i + 1, true, Alignment::left, pal, STR_FAT_LABEL_NAMED.c_str(), imgLabel[0] == 0 ? STR_UNTITLED.c_str() : imgLabel);
+					font->print(-1, i + 1, true, "[R]", Alignment::right, pal);
 				} else {
 					font->print(0, i + 1, true, STR_FAT_LABEL, Alignment::left, pal);
 					font->print(-1, i + 1, true, "[x]", Alignment::right, pal);
@@ -186,7 +197,7 @@ void dm_drawBottomScreen(void) {
 			break;
 		case DriveMenuOperation::sysNand:
 			font->print(0, 0, false, STR_SYSNAND_LABEL);
-			font->printf(0, 1, false, Alignment::left, Palette::white, STR_SYSNAND_FAT.c_str(), getDriveBytes(fatSize).c_str());
+			font->printf(0, 1, false, Alignment::left, Palette::white, STR_SYSNAND_FAT.c_str(), getDriveBytes(nandSize).c_str());
 			font->printf(0, 2, false, Alignment::left, Palette::white, STR_N_FREE.c_str(), getDriveBytes(getBytesFree("nand:/")).c_str());
 			break;
 		case DriveMenuOperation::fatImage:
@@ -281,6 +292,12 @@ void driveMenu (void) {
 				if (REG_SCFG_MC != stored_SCFG_MC) {
 					break;
 				}
+				if (sdMounted && sdRemoved) {
+					currentDrive = Drive::sdCard;
+					chdir("sd:/");
+					sdUnmount();
+					break;
+				}
 			}
 		} while (!(pressed & (KEY_UP | KEY_DOWN | KEY_LEFT | KEY_RIGHT | KEY_A | KEY_B | KEY_X | KEY_L | KEY_START
 #ifdef SCREENSWAP
@@ -379,7 +396,7 @@ void driveMenu (void) {
 					currentDrive = Drive::sdCard;
 					chdir("sd:/");
 					sdUnmount();
-				} else {
+				} else if(!sdRemoved) {
 					sdMounted = sdMount();
 				}
 			} else {
diff --git a/arm9/source/driveOperations.cpp b/arm9/source/driveOperations.cpp
index 8721667..cc860e3 100644
--- a/arm9/source/driveOperations.cpp
+++ b/arm9/source/driveOperations.cpp
@@ -12,6 +12,7 @@
 #include "dldi-include.h"
 #include "lzss.h"
 #include "ramd.h"
+#include "my_sd.h"
 #include "nandio.h"
 #include "imgio.h"
 #include "tonccpy.h"
@@ -154,9 +155,7 @@ TWL_CODE void nandUnmount(void) {
 }
 
 bool sdMount(void) {
-	extern const DISC_INTERFACE __my_io_dsisd;
-
-	fatMountSimple("sd", &__my_io_dsisd);
+	fatMountSimple("sd", __my_io_dsisd());
 	if (sdFound()) {
 		sdMountedDone = true;
 		fatGetVolumeLabel("sd", sdLabel);
@@ -178,6 +177,7 @@ u64 getBytesFree(const char* drivePath) {
 
 void sdUnmount(void) {
 	fatUnmount("sd");
+	my_sdio_Shutdown();
 	sdLabel[0] = '\0';
 	sdSize = 0;
 	sdMounted = false;
@@ -418,3 +418,22 @@ void imgUnmount(void) {
 	imgSize = 0;
 	imgMounted = false;
 }
+
+bool driveWritable(Drive drive) {
+	switch(drive) {
+		case Drive::sdCard:
+			return __my_io_dsisd()->features & FEATURE_MEDIUM_CANWRITE;
+		case Drive::flashcard:
+			return dldiGetInternal()->features & FEATURE_MEDIUM_CANWRITE;
+		case Drive::ramDrive:
+			return io_ram_drive.features & FEATURE_MEDIUM_CANWRITE;
+		case Drive::nand:
+			return io_dsi_nand.features & FEATURE_MEDIUM_CANWRITE;
+		case Drive::nitroFS:
+			return false;
+		case Drive::fatImg:
+			return io_img.features & FEATURE_MEDIUM_CANWRITE;
+	}
+
+	return false;
+}
diff --git a/arm9/source/driveOperations.h b/arm9/source/driveOperations.h
index e50bd27..4763e32 100644
--- a/arm9/source/driveOperations.h
+++ b/arm9/source/driveOperations.h
@@ -13,8 +13,6 @@ enum class Drive : u8 {
 	fatImg
 };
 
-#define DRIVE_WRITABLE(drive) (drive < Drive::nand)
-
 extern u8 stored_SCFG_MC;
 
 extern bool nandMounted;
@@ -58,5 +56,6 @@ extern void nitroUnmount(void);
 extern bool imgMount(const char* imgName);
 extern void imgUnmount(void);
 extern u64 getBytesFree(const char* drivePath);
+extern bool driveWritable(Drive drive);
 
 #endif //FLASHCARD_H
diff --git a/arm9/source/file_browse.cpp b/arm9/source/file_browse.cpp
index 082a06f..aea95ed 100644
--- a/arm9/source/file_browse.cpp
+++ b/arm9/source/file_browse.cpp
@@ -40,6 +40,7 @@
 #include "dumpOperations.h"
 #include "font.h"
 #include "hexEditor.h"
+#include "my_sd.h"
 #include "keyboard.h"
 #include "ndsInfo.h"
 #include "startMenu.h"
@@ -280,6 +281,9 @@ FileOperation fileBrowse_A(DirEntry* entry, char path[PATH_MAX]) {
 			pressed = keysDownRepeat();
 			held = keysHeld();
 			swiWaitForVBlank();
+
+			if(currentDrive == Drive::sdCard && sdRemoved)
+				return FileOperation::none;
 		} while (!(pressed & (KEY_UP| KEY_DOWN | KEY_A | KEY_B | KEY_L))
 #ifdef SCREENSWAP
 				&& !(pressed & KEY_TOUCH)
@@ -647,6 +651,11 @@ std::string browseForFile (void) {
 			if (REG_SCFG_MC != stored_SCFG_MC) {
 				break;
 			}
+
+			if(currentDrive == Drive::sdCard && sdRemoved) {
+				screenMode = 0;
+				return "null";
+			}
 		} while (!(pressed & ~(KEY_R | KEY_TOUCH | KEY_LID)));
 
 		if (isDSiMode() && !pressed && currentDrive == Drive::flashcard && REG_SCFG_MC == 0x11 && flashcardMounted) {
diff --git a/arm9/source/hexEditor.cpp b/arm9/source/hexEditor.cpp
index f88c3ca..45791a9 100644
--- a/arm9/source/hexEditor.cpp
+++ b/arm9/source/hexEditor.cpp
@@ -5,6 +5,7 @@
 #include "font.h"
 #include "keyboard.h"
 #include "language.h"
+#include "my_sd.h"
 #include "screenshot.h"
 #include "tonccpy.h"
 
@@ -216,7 +217,7 @@ u32 search(u32 offset, FILE *file) {
 }
 
 void hexEditor(const char *path, Drive drive) {
-	FILE *file = fopen(path, DRIVE_WRITABLE(drive) ? "rb+" : "rb");
+	FILE *file = fopen(path, driveWritable(drive) ? "rb+" : "rb");
 
 	if(!file)
 		return;
@@ -287,6 +288,9 @@ void hexEditor(const char *path, Drive drive) {
 			// Print time
 			font->print(-1, 0, true, RetTime(), Alignment::right, Palette::blackGreen);
 			font->update(true);
+
+			if(currentDrive == Drive::sdCard && sdRemoved)
+				return;
 		} while(!held);
 
 		if(mode == 0) {
@@ -339,7 +343,7 @@ void hexEditor(const char *path, Drive drive) {
 				if((int)cursorPosition < bytesPerLine * maxLines - 1)
 					cursorPosition = std::min(cursorPosition + 1, fileSize - offset - 1);
 			} else if(pressed & KEY_A) {
-				if(DRIVE_WRITABLE(drive)) {
+				if(driveWritable(drive)) {
 					mode = 2;
 				}
 			} else if(pressed & KEY_B) {
diff --git a/arm9/source/main.cpp b/arm9/source/main.cpp
index 3e38049..15194bf 100644
--- a/arm9/source/main.cpp
+++ b/arm9/source/main.cpp
@@ -37,6 +37,7 @@
 #include "fileOperations.h"
 #include "font.h"
 #include "language.h"
+#include "my_sd.h"
 #include "nitrofs.h"
 #include "tonccpy.h"
 #include "version.h"
@@ -110,8 +111,8 @@ int main(int argc, char **argv) {
 	tonccpy(BG_PALETTE, gm9i_logoPal, gm9i_logoPalLen);
 
 	font->print(1, 1, false, titleName);
-	font->print(1, 2, false, "---------------------------------------");
-	font->print(1, 3, false, "https:/github.com/DS-Homebrew/GodMode9i");
+	font->print(1, 2, false, "----------------------------------------");
+	font->print(1, 3, false, "https://github.com/DS-Homebrew/GodMode9i");
 
 	fifoWaitValue32(FIFO_USER_06);
 	if (fifoGetValue32(FIFO_USER_03) == 0) arm7SCFGLocked = true;
@@ -138,15 +139,16 @@ int main(int argc, char **argv) {
 
 	font->clear(false);
 	font->print(1, 1, false, titleName);
-	font->print(1, 2, false, "---------------------------------------");
-	font->print(1, 3, false, "https:/github.com/DS-Homebrew/GodMode9i");
+	font->print(1, 2, false, "----------------------------------------");
+	font->print(1, 3, false, "https://github.com/DS-Homebrew/GodMode9i");
 	font->print(-2, -2, false, "Mounting drive(s)...", Alignment::right);
 	font->update(false);
 
 	sysSetCartOwner (BUS_OWNER_ARM9);	// Allow arm9 to access GBA ROM
 
 	if (isDSiMode() || !isRegularDS) {
-		if (*(u8*)(0x2FFFD08) == 0) {
+		fifoSetValue32Handler(FIFO_USER_04, sdStatusHandler, nullptr);
+		if (!sdRemoved) {
 			sdMounted = sdMount();
 		}
 	}
diff --git a/arm9/source/my_sd.c b/arm9/source/my_sd.c
index 0be3397..1e07877 100644
--- a/arm9/source/my_sd.c
+++ b/arm9/source/my_sd.c
@@ -1,9 +1,18 @@
-#include <nds/disc_io.h>
+#include "my_sd.h"
+
 #include <nds/fifocommon.h>
 #include <nds/fifomessages.h>
 #include <nds/system.h>
 #include <nds/arm9/cache.h>
 
+volatile bool sdRemoved = false;
+volatile bool sdWriteLocked = false;
+
+void sdStatusHandler(u32 sdIrqStatus, void *userdata) {
+	sdRemoved = (sdIrqStatus & BIT(5)) == 0;
+	sdWriteLocked = (sdIrqStatus & BIT(7)) == 0;
+}
+
 //---------------------------------------------------------------------------------
 bool my_sdio_Startup() {
 //---------------------------------------------------------------------------------
@@ -58,6 +67,9 @@ bool my_sdio_ReadSectors(sec_t sector, sec_t numSectors,void* buffer) {
 //---------------------------------------------------------------------------------
 bool my_sdio_WriteSectors(sec_t sector, sec_t numSectors,const void* buffer) {
 //---------------------------------------------------------------------------------
+	if(sdWriteLocked)
+		return false;
+
 	FifoMessage msg;
 
 	DC_FlushRange(buffer,numSectors * 512);
@@ -86,10 +98,16 @@ bool my_sdio_ClearStatus() {
 //---------------------------------------------------------------------------------
 bool my_sdio_Shutdown() {
 //---------------------------------------------------------------------------------
-	return true;
+	fifoSendValue32(FIFO_SDMMC,SDMMC_SD_STOP);
+
+	fifoWaitValue32(FIFO_SDMMC);
+
+	int result = fifoGetValue32(FIFO_SDMMC);
+
+	return result == 1;
 }
 
-const DISC_INTERFACE __my_io_dsisd = {
+const DISC_INTERFACE __my_io_dsisd_rw = {
 	DEVICE_TYPE_DSI_SD,
 	FEATURE_MEDIUM_CANREAD | FEATURE_MEDIUM_CANWRITE,
 	(FN_MEDIUM_STARTUP)&my_sdio_Startup,
@@ -99,3 +117,18 @@ const DISC_INTERFACE __my_io_dsisd = {
 	(FN_MEDIUM_CLEARSTATUS)&my_sdio_ClearStatus,
 	(FN_MEDIUM_SHUTDOWN)&my_sdio_Shutdown
 };
+
+const DISC_INTERFACE __my_io_dsisd_r = {
+	DEVICE_TYPE_DSI_SD,
+	FEATURE_MEDIUM_CANREAD,
+	(FN_MEDIUM_STARTUP)&my_sdio_Startup,
+	(FN_MEDIUM_ISINSERTED)&my_sdio_IsInserted,
+	(FN_MEDIUM_READSECTORS)&my_sdio_ReadSectors,
+	(FN_MEDIUM_WRITESECTORS)&my_sdio_WriteSectors,
+	(FN_MEDIUM_CLEARSTATUS)&my_sdio_ClearStatus,
+	(FN_MEDIUM_SHUTDOWN)&my_sdio_Shutdown
+};
+
+const DISC_INTERFACE *__my_io_dsisd() {
+	return sdWriteLocked ? &__my_io_dsisd_r : &__my_io_dsisd_rw;
+}
diff --git a/arm9/source/my_sd.h b/arm9/source/my_sd.h
new file mode 100644
index 0000000..3eb6bfc
--- /dev/null
+++ b/arm9/source/my_sd.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#include <nds/disc_io.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern volatile bool sdRemoved;
+extern volatile bool sdWriteLocked;
+
+void sdStatusHandler(u32 sdIrqStatus, void *userdata);
+
+bool my_sdio_Shutdown();
+
+const DISC_INTERFACE *__my_io_dsisd();
+
+#ifdef __cplusplus
+}
+#endif