diff --git a/snes/fatfstest/config.h b/snes/fatfstest/config.h
index 127dbe7..93cacbd 100644
--- a/snes/fatfstest/config.h
+++ b/snes/fatfstest/config.h
@@ -20,4 +20,4 @@
 #define SHARED_ADDR     0x3d0000
 
 
-#define MMIO_DEBUG
+#undef MMIO_DEBUG
diff --git a/snes/fatfstest/debug.c b/snes/fatfstest/debug.c
index 5295008..a53ff70 100644
--- a/snes/fatfstest/debug.c
+++ b/snes/fatfstest/debug.c
@@ -93,7 +93,7 @@ void _print_screen(word y, char *buffer){
         *(byte*)0x2118 = *buffer-32;
         x++;
         buffer++;
-        //waitForVBlank();
+        waitForVBlank();
     }
 }
 void _print_console(const char *buffer){
diff --git a/snes/fatfstest/diskio.c b/snes/fatfstest/diskio.c
index 23bd456..10a76cb 100644
--- a/snes/fatfstest/diskio.c
+++ b/snes/fatfstest/diskio.c
@@ -40,22 +40,22 @@ DSTATUS disk_initialize (BYTE drv) {
     
     byte retval;
     #ifdef MMIO_DEBUG
-    printfc("SNES::disk_initialize called drv=%i stat=%i\n",drv,Stat);
+    printfc("SNES::disk_initialize: called drv=%i stat=%i\n",drv,Stat);
     #endif
     if (drv) return STA_NOINIT;             /* Supports only single drive */
     Stat |= STA_NOINIT;
     #ifdef MMIO_DEBUG
-    printfc("SNES::disk_initialize stat=%i\n",Stat);
+    printfc("SNES::disk_initialize: stat=%i\n",Stat);
     #endif
     *(byte*) MMIO_RETVAL = STA_VOID;
     *(byte*) MMIO_CMD = CMD_INIT;    
     #ifdef MMIO_DEBUG
-    printfc("SNES::disk_initialize poll retval\n");
+    printfc("SNES::disk_initialize: poll retval\n");
     #endif
     while((retval = *(byte*) MMIO_RETVAL) == STA_VOID);
     Stat &= ~STA_NOINIT;                    /* When device goes ready, clear STA_NOINIT */
     #ifdef MMIO_DEBUG
-    printfc("SNES::disk_initialize done Stat=%i\n",Stat);
+    printfc("SNES::disk_initialize: done Stat=%i\n",Stat);
     #endif
     return Stat;
 }
@@ -88,15 +88,15 @@ DRESULT disk_read (
     word i;
     
     //#ifdef MMIO_DEBUG
-    printfc("SNES::disk_read called sector=%li count=%i\n",sector,count);
+    printfc("SNES::disk_read: sector=%li count=%i\n",sector,count);
     //#endif
     if (drv || !count) return RES_PARERR;
     #ifdef MMIO_DEBUG
-    printfc("SNES::disk_read drv ok\n");
+    printfc("SNES::disk_read: drv ok\n");
     #endif
     if (Stat & STA_NOINIT) return RES_NOTRDY;
     #ifdef MMIO_DEBUG
-    printfc("SNES::disk_read sta ok\n");
+    printfc("SNES::disk_read: sta ok\n");
     #endif
 
     *(byte*) MMIO_RETVAL = STA_VOID;
@@ -110,13 +110,13 @@ DRESULT disk_read (
     *(byte*) MMIO_COUNT = count;    
 
     #ifdef MMIO_DEBUG
-    printfc("SNES::disk_read poll retval\n");
+    printfc("SNES::disk_read: poll retval\n");
     #endif
     while((retval = *(byte*) MMIO_RETVAL) == STA_VOID);
     
     
     #ifdef MMIO_DEBUG
-    printfc("SNES::disk_read copy buffer to %lx\n",SHARED_ADDR);
+    printfc("SNES::disk_read: copy buffer to %lx\n",SHARED_ADDR);
     #endif
     for (i=0;i<(count*512);i++){
         buff[i]  = *(byte*)(SHARED_ADDR+i);
diff --git a/tools/bsnes/chip/fatfs/config.h b/tools/bsnes/chip/fatfs/config.h
index 639399d..8b245ab 100644
--- a/tools/bsnes/chip/fatfs/config.h
+++ b/tools/bsnes/chip/fatfs/config.h
@@ -17,6 +17,6 @@
 #define SHARED_MAX_SIZE     512
 #define SHARED_ADDR     0x3d0000
 
-#undef  MMIO_DEBUG
-#undef  FATFS_DEBUG
+#define   MMIO_DEBUG
+#define   FATFS_DEBUG
 #define DISKIO_DEBUG 1
\ No newline at end of file
diff --git a/tools/bsnes/chip/fatfs/fatfs.cpp b/tools/bsnes/chip/fatfs/fatfs.cpp
index 3699011..0218353 100644
--- a/tools/bsnes/chip/fatfs/fatfs.cpp
+++ b/tools/bsnes/chip/fatfs/fatfs.cpp
@@ -102,7 +102,9 @@ void FATFS::mmio_write(unsigned addr, uint8 data) {
       fflush(stderr);
   }
   if (addr >= MMIO_SECTOR01 && addr <= MMIO_SECTOR04){
-      sector = data << ( (3 - ( addr - MMIO_SECTOR01))  << 3);
+      if (addr == MMIO_SECTOR01)
+        sector = 0;
+      sector |= data << ( (3 - ( addr - MMIO_SECTOR01))  << 3);
       #ifdef FATFS_DEBUG
       printf("BSNES::mmio_write set sector: byte=%i val=%i sector=%i \n",(3 - ( addr - MMIO_SECTOR01)),data,sector);
       #endif