diff --git a/include/dolphin/CARDPriv.h b/include/dolphin/CARDPriv.h
index 678df8ee..a7702cb0 100644
--- a/include/dolphin/CARDPriv.h
+++ b/include/dolphin/CARDPriv.h
@@ -5,12 +5,12 @@
 extern "C" {
 #endif
 
-#define CARD_FAT_AVAIL          0x0000u
-#define CARD_FAT_CHECKSUM       0x0000u
-#define CARD_FAT_CHECKSUMINV    0x0001u
-#define CARD_FAT_CHECKCODE      0x0002u
-#define CARD_FAT_FREEBLOCKS     0x0003u
-#define CARD_FAT_LASTSLOT       0x0004u
+#define CARD_FAT_AVAIL 0x0000u
+#define CARD_FAT_CHECKSUM 0x0000u
+#define CARD_FAT_CHECKSUMINV 0x0001u
+#define CARD_FAT_CHECKCODE 0x0002u
+#define CARD_FAT_FREEBLOCKS 0x0003u
+#define CARD_FAT_LASTSLOT 0x0004u
 
 #define CARD_PAGE_SIZE 128u
 #define CARD_SEG_SIZE 512u
@@ -20,28 +20,35 @@ extern "C" {
 
 #define CARD_MAX_MOUNT_STEP (CARD_NUM_SYSTEM_BLOCK + 2)
 
-typedef struct CARDDir
-{
-    u8      gameName[4];
-    u8      company[2];
-    u8      _padding0;
-    u8      bannerFormat;
-    u8      fileName[CARD_FILENAME_MAX];
-    u32     time;           // seconds since 01/01/2000 midnight
+typedef struct CARDDir {
+  u8 gameName[4];
+  u8 company[2];
+  u8 _padding0;
+  u8 bannerFormat;
+  u8 fileName[CARD_FILENAME_MAX];
+  u32 time; // seconds since 01/01/2000 midnight
 
-    u32     iconAddr;       // 0xffffffff if not used
-    u16     iconFormat;
-    u16     iconSpeed;
+  u32 iconAddr; // 0xffffffff if not used
+  u16 iconFormat;
+  u16 iconSpeed;
 
-    u8      permission;
-    u8      copyTimes;
-    u16     startBlock;
-    u16     length;
-    u8      _padding1[2];
+  u8 permission;
+  u8 copyTimes;
+  u16 startBlock;
+  u16 length;
+  u8 _padding1[2];
 
-    u32     commentAddr;    // 0xffffffff if not used
+  u32 commentAddr; // 0xffffffff if not used
 } CARDDir;
 
+typedef struct CARDDirCheck {
+  u8 padding0[64 - 2 * 4];
+  u16 padding1;
+  s16 checkCode;
+  u16 checkSum;
+  u16 checkSumInv;
+} CARDDirCheck;
+
 typedef struct CARDControl {
   BOOL attached;
   s32 result;
@@ -57,7 +64,7 @@ typedef struct CARDControl {
   u32 scramble;
   DSPTaskInfo task;
   void* workArea;
-  CARDDir* dir;
+  CARDDir* currentDir;
   u16* currentFat;
   OSThreadQueue threadQueue;
   u8 cmd[9];
@@ -95,15 +102,17 @@ typedef struct CARDID {
   u16 checkSumInv;
 } CARDID;
 
-#define CARDIsValidBlockNo(card, iBlock)    (CARD_NUM_SYSTEM_BLOCK <= (iBlock) && (iBlock) < (card)->cBlock)
+#define CARDIsValidBlockNo(card, iBlock) (CARD_NUM_SYSTEM_BLOCK <= (iBlock) && (iBlock) < (card)->cBlock)
+#define  __CARDGetDirCheck(dir)  ((CARDDirCheck*) &(dir)[CARD_MAX_FILE])
 
-CARDDir* __CARDGetDirBlock( CARDControl* card );
-u16* __CARDGetFatBlock   ( CARDControl* card );
+CARDDir* __CARDGetDirBlock(CARDControl* card);
+u16* __CARDGetFatBlock(CARDControl* card);
 s32 __CARDUpdateFatBlock(s32 chan, u16* fat, CARDCallback callback);
-
+void __CARDCheckSum(void* ptr, int length, u16* checkSum, u16* checkSumInv);
+u16 __CARDGetFontEncode();
 
 extern CARDControl __CARDBlock[2];
-extern DVDDiskID   __CARDDiskNone;
+extern DVDDiskID __CARDDiskNone;
 
 #ifdef __cplusplus
 }
diff --git a/include/dolphin/OSRtcPriv.h b/include/dolphin/OSRtcPriv.h
new file mode 100644
index 00000000..71a80a6f
--- /dev/null
+++ b/include/dolphin/OSRtcPriv.h
@@ -0,0 +1,31 @@
+#ifndef __OSRTCPRIV_H__
+#define __OSRTCPRIV_H__
+
+#include <types.h>
+
+typedef struct OSSram {
+  u16 checkSum;
+  u16 checkSumInv;
+  u32 ead0;
+  u32 ead1;
+  u32 counterBias;
+  s8 displayOffsetH;
+  u8 ntd;
+  u8 language;
+
+  u8 flags;
+} OSSram;
+
+typedef struct OSSramEx {
+  u8 flashID[2][12];
+  u32 wirelessKeyboardID;
+  u16 wirelessPadID[4];
+  u8 dvdErrorCode;
+  u8 _padding0;
+  u8 flashIDCheckSum[2];
+  u16 gbs;
+  u8 _padding1[2];
+} OSSramEx;
+
+OSSramEx* __OSLockSramEx();
+#endif
diff --git a/obj_files.mk b/obj_files.mk
index 1e2f8e75..1ab89283 100644
--- a/obj_files.mk
+++ b/obj_files.mk
@@ -819,7 +819,7 @@ CARD_FILES :=\
 	$(BUILD_DIR)/src/Dolphin/card/CARDUnlock.ep.o\
 	$(BUILD_DIR)/src/Dolphin/card/CARDRdwr.ep.o\
 	$(BUILD_DIR)/src/Dolphin/card/CARDBlock.ep.o\
-	$(BUILD_DIR)/asm/Dolphin/card/CARDDir.o\
+	$(BUILD_DIR)/src/Dolphin/card/CARDDir.ep.o\
 	$(BUILD_DIR)/asm/Dolphin/card/CARDCheck.o\
 	$(BUILD_DIR)/asm/Dolphin/card/CARDMount.o\
 	$(BUILD_DIR)/asm/Dolphin/card/CARDFormat.o\
diff --git a/src/Dolphin/card/CARDBios.c b/src/Dolphin/card/CARDBios.c
index 897cdc56..671a2392 100644
--- a/src/Dolphin/card/CARDBios.c
+++ b/src/Dolphin/card/CARDBios.c
@@ -447,7 +447,7 @@ void CARDInit(void) {
   OSRegisterResetFunction(&ResetFunctionInfo);
 }
 
-u16 __CARDGetFontEncode(s32 chan) { return __CARDEncode; }
+u16 __CARDGetFontEncode() { return __CARDEncode; }
 
 void __CARDSetDiskID(const DVDDiskID* id) {
   __CARDBlock[0].diskID = id ? id : &__CARDDiskNone;
diff --git a/src/Dolphin/card/CARDCheck.c b/src/Dolphin/card/CARDCheck.c
new file mode 100644
index 00000000..ceeb050b
--- /dev/null
+++ b/src/Dolphin/card/CARDCheck.c
@@ -0,0 +1,318 @@
+#include <dolphin/card.h>
+#include <dolphin/dsp.h>
+#include <dolphin/dvd.h>
+#include <dolphin/os.h>
+
+#include <dolphin/CARDPriv.h>
+#include <dolphin/OSRtcPriv.h>
+
+#define __CARDGetDirCheck(dir) ((CARDDirCheck*)&(dir)[CARD_MAX_FILE])
+
+void __CARDCheckSum(void* ptr, int length, u16* checksum, u16* checksumInv) {
+  u16* p;
+  int i;
+
+  length /= sizeof(u16);
+  *checksum = *checksumInv = 0;
+  for (i = 0, p = ptr; i < length; i++, p++) {
+    *checksum += *p;
+    *checksumInv += ~*p;
+  }
+  if (*checksum == 0xffff) {
+    *checksum = 0;
+  }
+  if (*checksumInv == 0xffff) {
+    *checksumInv = 0;
+  }
+}
+
+static s32 VerifyID(CARDControl* card) {
+  CARDID* id;
+  u16 checksum;
+  u16 checksumInv;
+  OSSramEx* sramEx;
+  OSTime rand;
+  int i;
+
+  id = card->workArea;
+
+  if (id->deviceID != 0 || id->size != card->size) {
+    return CARD_RESULT_BROKEN;
+  }
+
+  __CARDCheckSum(id, sizeof(CARDID) - sizeof(u32), &checksum, &checksumInv);
+  if (id->checkSum != checksum || id->checkSumInv != checksumInv) {
+    return CARD_RESULT_BROKEN;
+  }
+
+  rand = *(OSTime*)&id->serial[12];
+  sramEx = __OSLockSramEx();
+
+  for (i = 0; i < 12; i++) {
+    rand = (rand * 1103515245 + 12345) >> 16;
+    if (id->serial[i] != (u8)(sramEx->flashID[card - __CARDBlock][i] + rand)) {
+      __OSUnlockSramEx(FALSE);
+      return CARD_RESULT_BROKEN;
+    }
+    rand = ((rand * 1103515245 + 12345) >> 16) & 0x7FFF;
+  }
+
+  __OSUnlockSramEx(FALSE);
+  if (id->encode != __CARDGetFontEncode()) {
+    return CARD_RESULT_ENCODING;
+  }
+
+  return CARD_RESULT_READY;
+}
+
+static s32 VerifyDir(CARDControl* card, int* outCurrent) {
+  CARDDir* dir[2];
+  CARDDirCheck* check[2];
+  u16 checkSum;
+  u16 checkSumInv;
+  int i;
+  int errors;
+  int current;
+
+  current = errors = 0;
+  for (i = 0; i < 2; i++) {
+    dir[i] = (CARDDir*)((u8*)card->workArea + (1 + i) * CARD_SYSTEM_BLOCK_SIZE);
+    check[i] = __CARDGetDirCheck(dir[i]);
+    __CARDCheckSum(dir[i], CARD_SYSTEM_BLOCK_SIZE - sizeof(u32), &checkSum, &checkSumInv);
+    if (check[i]->checkSum != checkSum || check[i]->checkSumInv != checkSumInv) {
+      ++errors;
+      current = i;
+      card->currentDir = 0;
+    }
+  }
+
+  if (0 == errors) {
+    if (card->currentDir == 0) {
+      if ((check[0]->checkCode - check[1]->checkCode) < 0) {
+        current = 0;
+      } else {
+        current = 1;
+      }
+      card->currentDir = dir[current];
+      memcpy(dir[current], dir[current ^ 1], CARD_SYSTEM_BLOCK_SIZE);
+    } else {
+      current = (card->currentDir == dir[0]) ? 0 : 1;
+    }
+  }
+  if (outCurrent) {
+    *outCurrent = current;
+  }
+  return errors;
+}
+
+static s32 VerifyFAT(CARDControl* card, int* outCurrent) {
+  u16* fat[2];
+  u16* fatp;
+  u16 nBlock;
+  u16 cFree;
+  int i;
+  u16 checkSum;
+  u16 checkSumInv;
+  int errors;
+  int current;
+
+  current = errors = 0;
+  for (i = 0; i < 2; i++) {
+    fatp = fat[i] = (u16*)((u8*)card->workArea + (3 + i) * CARD_SYSTEM_BLOCK_SIZE);
+
+    __CARDCheckSum(&fatp[CARD_FAT_CHECKCODE], CARD_SYSTEM_BLOCK_SIZE - sizeof(u32), &checkSum, &checkSumInv);
+    if (fatp[CARD_FAT_CHECKSUM] != checkSum || fatp[CARD_FAT_CHECKSUMINV] != checkSumInv) {
+      ++errors;
+      current = i;
+      card->currentFat = 0;
+      continue;
+    }
+
+    cFree = 0;
+    for (nBlock = CARD_NUM_SYSTEM_BLOCK; nBlock < card->cBlock; nBlock++) {
+      if (fatp[nBlock] == CARD_FAT_AVAIL) {
+        cFree++;
+      }
+    }
+    if (cFree != fatp[CARD_FAT_FREEBLOCKS]) {
+      ++errors;
+      current = i;
+      card->currentFat = 0;
+      continue;
+    }
+  }
+
+  if (0 == errors) {
+    if (card->currentFat == 0) {
+      if (((s16)fat[0][CARD_FAT_CHECKCODE] - (s16)fat[1][CARD_FAT_CHECKCODE]) < 0) {
+        current = 0;
+      } else {
+        current = 1;
+      }
+      card->currentFat = fat[current];
+      memcpy(fat[current], fat[current ^ 1], CARD_SYSTEM_BLOCK_SIZE);
+    } else {
+      current = (card->currentFat == fat[0]) ? 0 : 1;
+    }
+  }
+  if (outCurrent) {
+    *outCurrent = current;
+  }
+  return errors;
+}
+
+s32 __CARDVerify(CARDControl* card) {
+  s32 result;
+  int errors;
+
+  result = VerifyID(card);
+  if (result < 0) {
+    return result;
+  }
+
+  errors = VerifyDir(card, NULL);
+  errors += VerifyFAT(card, NULL);
+  switch (errors) {
+  case 0:
+    return CARD_RESULT_READY;
+  case 1:
+    return CARD_RESULT_BROKEN;
+  default:
+    return CARD_RESULT_BROKEN;
+  }
+}
+
+s32 CARDCheckExAsync(s32 chan, s32* xferBytes, CARDCallback callback) {
+  CARDControl* card;
+  CARDDir* dir[2];
+  u16* fat[2];
+  u16* map;
+  s32 result;
+  int errors;
+  int currentFat;
+  int currentDir;
+  s32 fileNo;
+  u16 iBlock;
+  u16 cBlock;
+  u16 cFree;
+  BOOL updateFat = FALSE;
+  BOOL updateDir = FALSE;
+  BOOL updateOrphan = FALSE;
+
+  if (xferBytes) {
+    *xferBytes = 0;
+  }
+
+  result = __CARDGetControlBlock(chan, &card);
+  if (result < 0) {
+    return result;
+  }
+
+  result = VerifyID(card);
+  if (result < 0) {
+    return __CARDPutControlBlock(card, result);
+  }
+
+  errors = VerifyDir(card, &currentDir);
+  errors += VerifyFAT(card, &currentFat);
+  if (1 < errors) {
+    return __CARDPutControlBlock(card, CARD_RESULT_BROKEN);
+  }
+
+  dir[0] = (CARDDir*)((u8*)card->workArea + (1 + 0) * CARD_SYSTEM_BLOCK_SIZE);
+  dir[1] = (CARDDir*)((u8*)card->workArea + (1 + 1) * CARD_SYSTEM_BLOCK_SIZE);
+  fat[0] = (u16*)((u8*)card->workArea + (3 + 0) * CARD_SYSTEM_BLOCK_SIZE);
+  fat[1] = (u16*)((u8*)card->workArea + (3 + 1) * CARD_SYSTEM_BLOCK_SIZE);
+
+  switch (errors) {
+  case 0:
+    break;
+  case 1:
+    if (!card->currentDir) {
+      card->currentDir = dir[currentDir];
+      memcpy(dir[currentDir], dir[currentDir ^ 1], CARD_SYSTEM_BLOCK_SIZE);
+      updateDir = TRUE;
+    } else {
+      card->currentFat = fat[currentFat];
+      memcpy(fat[currentFat], fat[currentFat ^ 1], CARD_SYSTEM_BLOCK_SIZE);
+      updateFat = TRUE;
+    }
+    break;
+  }
+
+  map = fat[currentFat ^ 1];
+  memset(map, 0, CARD_SYSTEM_BLOCK_SIZE);
+
+  for (fileNo = 0; fileNo < CARD_MAX_FILE; fileNo++) {
+    CARDDir* ent;
+
+    ent = &card->currentDir[fileNo];
+    if (ent->gameName[0] == 0xff) {
+      continue;
+    }
+
+    for (iBlock = ent->startBlock, cBlock = 0; iBlock != 0xFFFF && cBlock < ent->length;
+         iBlock = card->currentFat[iBlock], ++cBlock) {
+      if (!CARDIsValidBlockNo(card, iBlock) || 1 < ++map[iBlock]) {
+        return __CARDPutControlBlock(card, CARD_RESULT_BROKEN);
+      }
+    }
+    if (cBlock != ent->length || iBlock != 0xFFFF) {
+      return __CARDPutControlBlock(card, CARD_RESULT_BROKEN);
+    }
+  }
+
+  cFree = 0;
+  for (iBlock = CARD_NUM_SYSTEM_BLOCK; iBlock < card->cBlock; iBlock++) {
+    u16 nextBlock;
+
+    nextBlock = card->currentFat[iBlock];
+    if (map[iBlock] == 0) {
+      if (nextBlock != CARD_FAT_AVAIL) {
+        card->currentFat[iBlock] = CARD_FAT_AVAIL;
+        updateOrphan = TRUE;
+      }
+      cFree++;
+    } else if (!CARDIsValidBlockNo(card, nextBlock) && nextBlock != 0xFFFF) {
+      return __CARDPutControlBlock(card, CARD_RESULT_BROKEN);
+    }
+  }
+  if (cFree != card->currentFat[CARD_FAT_FREEBLOCKS]) {
+    card->currentFat[CARD_FAT_FREEBLOCKS] = cFree;
+    updateOrphan = TRUE;
+  }
+  if (updateOrphan) {
+    __CARDCheckSum(&card->currentFat[CARD_FAT_CHECKCODE], CARD_SYSTEM_BLOCK_SIZE - sizeof(u32), &card->currentFat[CARD_FAT_CHECKSUM],
+                   &card->currentFat[CARD_FAT_CHECKSUMINV]);
+  }
+
+  memcpy(fat[currentFat ^ 1], fat[currentFat], CARD_SYSTEM_BLOCK_SIZE);
+
+  if (updateDir) {
+    if (xferBytes) {
+      *xferBytes = CARD_SYSTEM_BLOCK_SIZE;
+    }
+    return __CARDUpdateDir(chan, callback);
+  }
+
+  if (updateFat | updateOrphan) {
+    if (xferBytes) {
+      *xferBytes = CARD_SYSTEM_BLOCK_SIZE;
+    }
+    return __CARDUpdateFatBlock(chan, card->currentFat, callback);
+  }
+
+  __CARDPutControlBlock(card, CARD_RESULT_READY);
+  if (callback) {
+    BOOL enabled = OSDisableInterrupts();
+    callback(chan, CARD_RESULT_READY);
+    OSRestoreInterrupts(enabled);
+  }
+  return CARD_RESULT_READY;
+}
+
+s32 CARDCheckAsync(s32 chan, CARDCallback callback) {
+  s32 xferBytes;
+
+  return CARDCheckExAsync(chan, &xferBytes, callback);
+}
diff --git a/src/Dolphin/card/CARDDir.c b/src/Dolphin/card/CARDDir.c
new file mode 100644
index 00000000..1daecf8e
--- /dev/null
+++ b/src/Dolphin/card/CARDDir.c
@@ -0,0 +1,92 @@
+#include <dolphin/card.h>
+#include <dolphin/dsp.h>
+#include <dolphin/dvd.h>
+#include <dolphin/os.h>
+
+#include <dolphin/CARDPriv.h>
+
+CARDDir* __CARDGetDirBlock(CARDControl* card) { return card->currentDir; }
+
+static void WriteCallback(s32 chan, s32 result) {
+  CARDControl* card;
+  CARDCallback callback;
+
+  card = &__CARDBlock[chan];
+  if (0 <= result) {
+    CARDDir* dir0 = (CARDDir*)((u8*)card->workArea + 0x2000);
+    CARDDir* dir1 = (CARDDir*)((u8*)card->workArea + 0x4000);
+
+    if (card->currentDir == dir0) {
+      card->currentDir = dir1;
+      memcpy(dir1, dir0, 0x2000);
+    } else {
+      card->currentDir = dir0;
+      memcpy(dir0, dir1, 0x2000);
+    }
+  }
+
+error:
+  if (card->apiCallback == 0) {
+    __CARDPutControlBlock(card, result);
+  }
+  callback = card->eraseCallback;
+  if (callback) {
+    card->eraseCallback = 0;
+    callback(chan, result);
+  }
+}
+
+static void EraseCallback(s32 chan, s32 result) {
+  CARDControl* card;
+  CARDCallback callback;
+  CARDDir* dir;
+  u32 tmp[2];
+  u32 addr;
+
+  card = &__CARDBlock[chan];
+  if (result < 0) {
+    goto error;
+  }
+
+  dir = __CARDGetDirBlock(card);
+  addr = ((u32)dir - (u32)card->workArea) / 0x2000 * card->sectorSize;
+  result = __CARDWrite(chan, addr, 0x2000, dir, WriteCallback);
+  if (result < 0) {
+    goto error;
+  }
+
+  return;
+
+error:
+  if (card->apiCallback == 0) {
+    __CARDPutControlBlock(card, result);
+  }
+  callback = card->eraseCallback;
+  if (callback) {
+    card->eraseCallback = 0;
+    callback(chan, result);
+  }
+}
+
+s32 __CARDUpdateDir(s32 chan, CARDCallback callback) {
+  CARDControl* card;
+  CARDDirCheck* check;
+  u32 tmp[2];
+  u32 addr;
+  CARDDir* dir;
+
+  card = &__CARDBlock[chan];
+  if (!card->attached) {
+    return CARD_RESULT_NOCARD;
+  }
+
+  dir = __CARDGetDirBlock(card);
+  check = __CARDGetDirCheck(dir);
+  ++check->checkCode;
+  __CARDCheckSum(dir, 0x2000 - sizeof(u32), &check->checkSum, &check->checkSumInv);
+  DCStoreRange(dir, 0x2000);
+
+  card->eraseCallback = callback;
+  addr = ((u32)dir - (u32)card->workArea) / 0x2000 * card->sectorSize;
+  return __CARDEraseSector(chan, addr, EraseCallback);
+}