diff --git a/sw/bootloader/src/fatfs/ffconf.h b/sw/bootloader/src/fatfs/ffconf.h
index 6fde966..e448f4f 100644
--- a/sw/bootloader/src/fatfs/ffconf.h
+++ b/sw/bootloader/src/fatfs/ffconf.h
@@ -34,7 +34,7 @@
 /* This option switches f_mkfs() function. (0:Disable or 1:Enable) */
 
 
-#define FF_USE_FASTSEEK	1
+#define FF_USE_FASTSEEK	0
 /* This option switches fast seek function. (0:Disable or 1:Enable) */
 
 
@@ -224,7 +224,7 @@
 / System Configurations
 /---------------------------------------------------------------------------*/
 
-#define FF_FS_TINY		0
+#define FF_FS_TINY		1
 /* This option switches tiny buffer configuration. (0:Normal or 1:Tiny)
 /  At the tiny configuration, size of file object (FIL) is shrinked FF_MAX_SS bytes.
 /  Instead of private sector buffer eliminated from the file object, common sector
diff --git a/sw/bootloader/src/sc64.c b/sw/bootloader/src/sc64.c
index c8411ee..3203c27 100644
--- a/sw/bootloader/src/sc64.c
+++ b/sw/bootloader/src/sc64.c
@@ -19,6 +19,7 @@ typedef enum {
     SC64_CMD_SD_SECTOR_SET      = 'I',
     SC64_CMD_SD_WRITE           = 'S',
     SC64_CMD_SD_READ            = 's',
+    SC64_CMD_DD_SD_DISK_INFO    = 'D',
 } cmd_id_t;
 
 typedef enum {
@@ -199,3 +200,11 @@ bool sc64_sd_read_sectors (uint32_t *address, uint32_t sector, uint32_t count) {
     }
     return sc64_execute_cmd(SC64_CMD_SD_READ, read_args, NULL);
 }
+
+bool sc64_dd_set_sd_disk_info (uint32_t *address, uint32_t count) {
+    uint32_t args[2] = { (uint32_t) (address), count };
+    if (sc64_execute_cmd(SC64_CMD_DD_SD_DISK_INFO, args, NULL)) {
+        return true;
+    }
+    return false;
+}
diff --git a/sw/bootloader/src/sc64.h b/sw/bootloader/src/sc64.h
index 9554cf8..92c16e7 100644
--- a/sw/bootloader/src/sc64.h
+++ b/sw/bootloader/src/sc64.h
@@ -29,6 +29,8 @@ typedef enum {
     CFG_ID_DD_DISK_STATE,
     CFG_ID_BUTTON_STATE,
     CFG_ID_BUTTON_MODE,
+    CFG_ID_ROM_EXTENDED_ENABLE,
+    CFG_ID_DD_SD_MODE,
 } cfg_id_t;
 
 typedef enum {
@@ -109,6 +111,7 @@ bool sc64_sd_card_get_status (void);
 bool sc64_sd_card_get_info (uint32_t *address);
 bool sc64_sd_write_sectors (uint32_t *address, uint32_t sector, uint32_t count);
 bool sc64_sd_read_sectors (uint32_t *address, uint32_t sector, uint32_t count);
+bool sc64_dd_set_sd_disk_info (uint32_t *address, uint32_t count);
 
 
 #endif
diff --git a/sw/bootloader/src/test.c b/sw/bootloader/src/test.c
index 76fc098..277e025 100644
--- a/sw/bootloader/src/test.c
+++ b/sw/bootloader/src/test.c
@@ -13,6 +13,8 @@ bool test_check (void) {
 }
 
 void test_execute (void) {
+    uint8_t card_info[32] __attribute__((aligned(8)));
+
     display_init(NULL);
 
     display_printf("SC64 Test suite\n\n");
@@ -27,18 +29,25 @@ void test_execute (void) {
         while (1);
     }
 
-    uint8_t card_info[32] __attribute__((aligned(8)));
-
     pi_dma_read((io32_t *) (SC64_BUFFERS->BUFFER), card_info, sizeof(card_info));
 
-    display_printf("CSD: 0x");
+    display_printf("SD Card registers:\n    CSD: 0x");
     for (int i = 0; i < 16; i++) {
         display_printf("%02X", card_info[i]);
     }
-    display_printf("\nCID: 0x");
+    display_printf("\n    CID: 0x");
     for (int i = 16; i < 32; i++) {
         display_printf("%02X", card_info[i]);
     }
+    display_printf("\n           ");
+    for (int i = 16; i < 32; i++) {
+        display_printf("%c ", card_info[i] >= ' ' ? card_info[i] : 0xFF);
+    }
+
+    if (sc64_sd_card_deinit()) {
+        display_printf("SD card deinit error!\n");
+        while (1);
+    }
 
     while (1);
 }
diff --git a/sw/controller/src/button.c b/sw/controller/src/button.c
index e2fbaf1..e8b67c1 100644
--- a/sw/controller/src/button.c
+++ b/sw/controller/src/button.c
@@ -1,5 +1,6 @@
 #include <stdint.h>
 #include "button.h"
+#include "dd.h"
 #include "fpga.h"
 #include "usb.h"
 
@@ -66,7 +67,7 @@ void button_process (void) {
                 break;
 
             case BUTTON_MODE_DD_DISK_SWAP:
-                // TODO: implement 64DD disk swapping
+                dd_handle_button();
                 p.trigger = false;
                 break;
 
diff --git a/sw/controller/src/cfg.c b/sw/controller/src/cfg.c
index 5c7adb9..f4a580c 100644
--- a/sw/controller/src/cfg.c
+++ b/sw/controller/src/cfg.c
@@ -25,6 +25,7 @@ typedef enum {
     CFG_ID_BUTTON_STATE,
     CFG_ID_BUTTON_MODE,
     CFG_ID_ROM_EXTENDED_ENABLE,
+    CFG_ID_DD_SD_MODE,
 } cfg_id_t;
 
 typedef enum {
@@ -106,6 +107,12 @@ static bool cfg_translate_address (uint32_t *address, uint32_t length, bool with
             return false;
         }
     }
+    if (*address >= 0x1FFE2000 && *address < 0x1FFE2800) {
+        if ((*address + length) <= 0x1FFE2800) {
+            *address = *address - 0x1FFE2000 + 0x05002000;
+            return false;
+        }
+    }
     return true;
 }
 
@@ -220,6 +227,9 @@ bool cfg_query (uint32_t *args) {
         case CFG_ID_ROM_EXTENDED_ENABLE:
             args[1] = (scr & CFG_SCR_ROM_EXTENDED_ENABLED);
             break;
+        case CFG_ID_DD_SD_MODE:
+            args[1] = dd_get_sd_mode();
+            break;
         default:
             return true;
     }
@@ -285,6 +295,9 @@ bool cfg_update (uint32_t *args) {
         case CFG_ID_ROM_EXTENDED_ENABLE:
             cfg_change_scr_bits(CFG_SCR_ROM_EXTENDED_ENABLED, args[1]);
             break;
+        case CFG_ID_DD_SD_MODE:
+            dd_set_sd_mode(args[1]);
+            break;
         default:
             return true;
     }
@@ -457,6 +470,14 @@ void cfg_process (void) {
                     return;
                 }
                 break;
+            
+            case 'D':
+                if (cfg_translate_address(&args[0], args[1], false)) {
+                    cfg_set_error(CFG_ERROR_BAD_ADDRESS);
+                    return;
+                }
+                dd_set_sd_disk_info(args[0], args[1]);
+                break;
 
             default:
                 cfg_set_error(CFG_ERROR_UNKNOWN_CMD);
diff --git a/sw/controller/src/dd.c b/sw/controller/src/dd.c
index 614c736..0d0d3e0 100644
--- a/sw/controller/src/dd.c
+++ b/sw/controller/src/dd.c
@@ -3,13 +3,17 @@
 #include "fpga.h"
 #include "hw.h"
 #include "rtc.h"
+#include "sd.h"
 #include "usb.h"
 
 
 #define DD_SECTOR_MAX_SIZE          (232)
 #define DD_BLOCK_DATA_SECTORS_NUM   (85)
-#define DD_BLOCK_BUFFER_ADDRESS     (0x03BC0000UL - (DD_SECTOR_MAX_SIZE * DD_BLOCK_DATA_SECTORS_NUM))
+#define DD_BLOCK_BUFFER_SIZE        (ALIGN(DD_SECTOR_MAX_SIZE * DD_BLOCK_DATA_SECTORS_NUM, SD_SECTOR_SIZE) + SD_SECTOR_SIZE)
+#define DD_BLOCK_BUFFER_ADDRESS     (0x03BC0000UL - DD_BLOCK_BUFFER_SIZE)
 #define DD_SECTOR_BUFFER_ADDRESS    (0x05002800UL)
+#define DD_SD_SECTOR_TABLE_SIZE     (DD_BLOCK_BUFFER_SIZE / SD_SECTOR_SIZE)
+#define DD_SD_MAX_DISKS             (4)
 
 #define DD_DRIVE_ID_RETAIL          (0x0003)
 #define DD_DRIVE_ID_DEVELOPMENT     (0x0004)
@@ -47,8 +51,7 @@ enum state {
     STATE_NEXT_BLOCK,
 };
 
-
-typedef union sector_info {
+typedef union {
     uint32_t full;
     struct {
         uint8_t sector_num;
@@ -58,6 +61,11 @@ typedef union sector_info {
     };
 } sector_info_t;
 
+typedef struct {
+    uint32_t thb_table_address;
+    uint32_t sector_table_address;
+} sd_disk_info_t;
+
 struct process {
     enum state state;
     rtc_time_t time;
@@ -73,7 +81,12 @@ struct process {
     sector_info_t sector_info;
     bool block_ready;
     bool block_valid;
+    uint32_t block_offset;
     dd_drive_type_t drive_type;
+    bool sd_mode;
+    uint8_t sd_current_disk;
+    sd_disk_info_t sd_disk_info[DD_SD_MAX_DISKS];
+    uint32_t sd_sector_table[DD_SD_SECTOR_TABLE_SIZE];
 };
 
 
@@ -87,28 +100,88 @@ static uint16_t dd_track_head_block (void) {
     return (track | head | block);
 }
 
+static uint32_t dd_fill_sd_sector_table (uint32_t index) {
+    uint32_t tmp;
+    sd_disk_info_t info = p.sd_disk_info[p.sd_current_disk];
+    uint32_t thb_entry_address = (info.thb_table_address + (index * sizeof(uint32_t)));
+    fpga_mem_read(thb_entry_address, sizeof(uint32_t), (uint8_t *) (&tmp));
+    uint32_t start_offset = SWAP32(tmp);
+    if (start_offset == 0xFFFFFFFF) {
+        return 0;
+    }
+    p.block_offset = (start_offset % SD_SECTOR_SIZE);
+    uint32_t block_length = ((p.sector_info.sector_size + 1) * DD_BLOCK_DATA_SECTORS_NUM);
+    uint32_t end_offset = ((start_offset + block_length) - 1); // CHECK THIS
+    uint32_t starting_sector = (start_offset / SD_SECTOR_SIZE);
+    uint32_t sectors = (1 + ((end_offset / SD_SECTOR_SIZE) - starting_sector));
+    for (int i = 0; i < sectors; i++) {
+        uint32_t sector_entry_address = info.sector_table_address + ((starting_sector + i) * sizeof(uint32_t));
+        fpga_mem_read(sector_entry_address, sizeof(uint32_t), (uint8_t *) (&tmp));
+        p.sd_sector_table[i] = SWAP32(tmp);
+    }
+    return sectors;
+}
+
 static bool dd_block_read_request (void) {
-    usb_tx_info_t packet_info;
-    usb_create_packet(&packet_info, PACKET_CMD_DD_REQUEST);
-    packet_info.data_length = 12;
-    packet_info.data[0] = 1;
-    packet_info.data[1] = DD_BLOCK_BUFFER_ADDRESS;
-    packet_info.data[2] = dd_track_head_block();
-    p.block_ready = false;
-    return usb_enqueue_packet(&packet_info);
+    uint16_t index = dd_track_head_block();
+    uint32_t buffer_address = DD_BLOCK_BUFFER_ADDRESS;
+
+    if (p.sd_mode) {
+        dd_set_block_ready(false);
+        uint32_t sectors = dd_fill_sd_sector_table(index);
+        if (sectors > 0) {
+            for (int i = 0; i < sectors; i++) {
+                if (sd_read_sectors(buffer_address, p.sd_sector_table[i], 1)) {
+                    return true;
+                }
+                buffer_address += SD_SECTOR_SIZE;
+            }
+            dd_set_block_ready(true);
+        }
+        return true;
+    } else {
+        usb_tx_info_t packet_info;
+        usb_create_packet(&packet_info, PACKET_CMD_DD_REQUEST);
+        packet_info.data_length = 12;
+        packet_info.data[0] = 1;
+        packet_info.data[1] = buffer_address;
+        packet_info.data[2] = index;
+        p.block_ready = false;
+        p.block_offset = 0;
+        return usb_enqueue_packet(&packet_info);
+    }
 }
 
 static bool dd_block_write_request (void) {
-    usb_tx_info_t packet_info;
-    usb_create_packet(&packet_info, PACKET_CMD_DD_REQUEST);
-    packet_info.data_length = 12;
-    packet_info.data[0] = 2;
-    packet_info.data[1] = DD_BLOCK_BUFFER_ADDRESS;
-    packet_info.data[2] = dd_track_head_block();
-    packet_info.dma_length = (p.sector_info.sector_size + 1) * DD_BLOCK_DATA_SECTORS_NUM;
-    packet_info.dma_address = DD_BLOCK_BUFFER_ADDRESS;
-    p.block_ready = false;
-    return usb_enqueue_packet(&packet_info);
+    uint32_t index = dd_track_head_block();
+    uint32_t buffer_address = DD_BLOCK_BUFFER_ADDRESS;
+
+    if (p.sd_mode) {
+        dd_set_block_ready(false);
+        uint32_t sectors = dd_fill_sd_sector_table(index);
+        if (sectors > 0) {
+            for (int i = 0; i < sectors; i++) {
+                if (sd_write_sectors(buffer_address, p.sd_sector_table[i], 1)) {
+                    return true;
+                }
+                buffer_address += SD_SECTOR_SIZE;
+            }
+            dd_set_block_ready(true);
+        }
+        return true;
+    } else {
+        usb_tx_info_t packet_info;
+        usb_create_packet(&packet_info, PACKET_CMD_DD_REQUEST);
+        packet_info.data_length = 12;
+        packet_info.data[0] = 2;
+        packet_info.data[1] = buffer_address;
+        packet_info.data[2] = index;
+        packet_info.dma_length = (p.sector_info.sector_size + 1) * DD_BLOCK_DATA_SECTORS_NUM;
+        packet_info.dma_address = buffer_address;
+        p.block_ready = false;
+        p.block_offset = 0;
+        return usb_enqueue_packet(&packet_info);
+    }
 }
 
 static void dd_set_cmd_response_ready (void) {
@@ -168,6 +241,29 @@ void dd_set_disk_state (dd_disk_state_t state) {
     fpga_reg_set(REG_DD_SCR, scr);
 }
 
+bool dd_get_sd_mode (void) {
+    return p.sd_mode;
+}
+
+void dd_set_sd_mode (bool value) {
+    p.sd_mode = value;
+}
+
+void dd_set_sd_disk_info (uint32_t address, uint32_t length) {
+    uint32_t tmp[2];
+    p.sd_current_disk = 0;
+    for (int i = 0; i < 4; i++) {
+        fpga_mem_read(address, sizeof(tmp), (uint8_t *) (tmp));
+        p.sd_disk_info[i].thb_table_address = SWAP32(tmp[0]);
+        p.sd_disk_info[i].sector_table_address = SWAP32(tmp[1]);
+        address += sizeof(tmp);
+    }
+}
+
+void dd_handle_button (void) {
+    // TODO: disk swap
+}
+
 void dd_init (void) {
     fpga_reg_set(REG_DD_SCR, 0);
     fpga_reg_set(REG_DD_HEAD_TRACK, 0);
@@ -178,6 +274,8 @@ void dd_init (void) {
     p.disk_spinning = false;
     p.bm_running = false;
     p.drive_type = DD_DRIVE_TYPE_RETAIL;
+    p.sd_mode = false;
+    p.sd_current_disk = 0;
 }
 
 void dd_process (void) {
@@ -365,7 +463,7 @@ void dd_process (void) {
 
             case STATE_SECTOR_READ:
                 fpga_mem_copy(
-                    DD_BLOCK_BUFFER_ADDRESS + (p.current_sector * (p.sector_info.sector_size + 1)),
+                    DD_BLOCK_BUFFER_ADDRESS + p.block_offset + (p.current_sector * (p.sector_info.sector_size + 1)),
                     DD_SECTOR_BUFFER_ADDRESS,
                     p.sector_info.sector_size + 1
                 );
@@ -377,7 +475,7 @@ void dd_process (void) {
             case STATE_SECTOR_WRITE:
                 fpga_mem_copy(
                     DD_SECTOR_BUFFER_ADDRESS,
-                    DD_BLOCK_BUFFER_ADDRESS + (p.current_sector * (p.sector_info.sector_size + 1)),
+                    DD_BLOCK_BUFFER_ADDRESS + p.block_offset + (p.current_sector * (p.sector_info.sector_size + 1)),
                     p.sector_info.sector_size + 1
                 );
                 p.current_sector += 1;
diff --git a/sw/controller/src/dd.h b/sw/controller/src/dd.h
index ab0f624..0f8d833 100644
--- a/sw/controller/src/dd.h
+++ b/sw/controller/src/dd.h
@@ -17,11 +17,15 @@ typedef enum {
 } dd_disk_state_t;
 
 
+void dd_set_block_ready (bool valid);
 dd_drive_type_t dd_get_drive_type (void);
 void dd_set_drive_type (dd_drive_type_t type);
 dd_disk_state_t dd_get_disk_state (void);
 void dd_set_disk_state (dd_disk_state_t state);
-void dd_set_block_ready (bool valid);
+bool dd_get_sd_mode (void);
+void dd_set_sd_mode (bool value);
+void dd_set_sd_disk_info (uint32_t address, uint32_t length);
+void dd_handle_button (void);
 void dd_init (void);
 void dd_process (void);
 
diff --git a/sw/controller/src/fpga.h b/sw/controller/src/fpga.h
index b7dfe65..c656f6a 100644
--- a/sw/controller/src/fpga.h
+++ b/sw/controller/src/fpga.h
@@ -55,6 +55,7 @@ typedef enum {
 } fpga_reg_t;
 
 
+#define	ALIGN(value, align)             (((value) + ((typeof(value))(align) - 1)) & ~((typeof(value))(align) - 1))
 #define SWAP16(x)                       ((((x) & 0xFF) << 8) | (((x) & 0xFF00) >> 8))
 #define SWAP32(x)                       (((x) & 0xFF) << 24 | ((x) & 0xFF00) << 8 | ((x) & 0xFF0000) >> 8 | ((x) & 0xFF000000) >> 24)
 
diff --git a/sw/controller/src/sd.c b/sw/controller/src/sd.c
index 318b70a..6a82406 100644
--- a/sw/controller/src/sd.c
+++ b/sw/controller/src/sd.c
@@ -6,7 +6,7 @@
 #include "sd.h"
 
 
-#define SD_BUFFER_ADDRESS               (0x05000000UL)
+#define SD_INIT_BUFFER_ADDRESS          (0x05002800UL)
 
 #define CMD6_ARG_CHECK_HS               (0x00FFFFF1UL)
 #define CMD6_ARG_SWITCH_HS              (0x80FFFFF1UL)
@@ -28,7 +28,10 @@
 #define R7_SUPPLY_VOLTAGE_27_36_V       (1 << 8)
 #define R7_CHECK_PATTERN                (0xAA << 0)
 
-#define SD_BLOCK_SIZE                   (512)
+#define SWITCH_FUNCTION_CURRENT_LIMIT   (SD_INIT_BUFFER_ADDRESS + 0)
+#define SWITCH_FUNCTION_GROUP_1         (SD_INIT_BUFFER_ADDRESS + 12)
+#define SWITCH_FUNCTION_GROUP_1_HS      (1 << 1)
+
 #define DAT_BLOCK_MAX_COUNT             (256)
 
 
@@ -166,7 +169,7 @@ static bool sd_acmd (uint8_t acmd, uint32_t arg, rsp_type_t rsp_type, void *rsp)
 }
 
 static void sd_dat_prepare (uint32_t address, uint32_t count, dat_mode_t mode) {
-    uint32_t length = (count * SD_BLOCK_SIZE);
+    uint32_t length = (count * SD_SECTOR_SIZE);
     uint32_t sd_dat = (((count - 1) << SD_DAT_BLOCKS_BIT) | SD_DAT_FIFO_FLUSH);
     uint32_t sd_dma_scr = DMA_SCR_START;
 
@@ -209,7 +212,7 @@ static bool sd_dat_wait (uint16_t timeout) {
 bool sd_card_init (void) {
     uint32_t arg;
     uint32_t rsp;
-    uint16_t sd_function;
+    uint16_t tmp;
 
     if (p.card_initialized) {
         return false;
@@ -289,7 +292,7 @@ bool sd_card_init (void) {
         return true;
     }
 
-    sd_dat_prepare(SD_BUFFER_ADDRESS, 1, DAT_READ);
+    sd_dat_prepare(SD_INIT_BUFFER_ADDRESS, 1, DAT_READ);
     if (sd_cmd(6, CMD6_ARG_CHECK_HS, RSP_R1, NULL)) {
         sd_dat_abort();
         sd_card_deinit();
@@ -300,9 +303,14 @@ bool sd_card_init (void) {
         sd_card_deinit();
         return true;
     }
-    fpga_mem_read(SD_BUFFER_ADDRESS + 12, 2, (uint8_t *) (&sd_function));
-    if (SWAP16(sd_function) & (1 << 1)) {
-        sd_dat_prepare(SD_BUFFER_ADDRESS, 1, DAT_READ);
+    fpga_mem_read(SWITCH_FUNCTION_CURRENT_LIMIT, 2, (uint8_t *) (&tmp));
+    if (SWAP16(tmp) == 0) {
+        sd_card_deinit();
+        return true;
+    }
+    fpga_mem_read(SWITCH_FUNCTION_GROUP_1, 2, (uint8_t *) (&tmp));
+    if (SWAP16(tmp) & SWITCH_FUNCTION_GROUP_1_HS) {
+        sd_dat_prepare(SD_INIT_BUFFER_ADDRESS, 1, DAT_READ);
         if (sd_cmd(6, CMD6_ARG_SWITCH_HS, RSP_R1, NULL)) {
             sd_dat_abort();
             sd_card_deinit();
@@ -313,8 +321,8 @@ bool sd_card_init (void) {
             sd_card_deinit();
             return true;
         }
-        fpga_mem_read(SD_BUFFER_ADDRESS + 12, 2, (uint8_t *) (&sd_function));
-        if (SWAP16(sd_function) & (1 << 1)) {
+        fpga_mem_read(SWITCH_FUNCTION_GROUP_1, 2, (uint8_t *) (&tmp));
+        if (SWAP16(tmp) & SWITCH_FUNCTION_GROUP_1_HS) {
             sd_set_clock(CLOCK_50MHZ);
         }
     }
@@ -352,7 +360,7 @@ bool sd_write_sectors (uint32_t address, uint32_t sector, uint32_t count) {
     }
 
     if (!p.card_type_block) {
-        sector *= SD_BLOCK_SIZE;
+        sector *= SD_SECTOR_SIZE;
     }
 
     while (count > 0) {
@@ -365,14 +373,14 @@ bool sd_write_sectors (uint32_t address, uint32_t sector, uint32_t count) {
             return true;
         }
         sd_dat_prepare(address, blocks, DAT_WRITE);
-        bool error = sd_dat_wait(1000);
-        sd_cmd(12, 0, RSP_R1b, NULL);
-        if (error) {
+        if (sd_dat_wait(1000)) {
             sd_dat_abort();
+            sd_cmd(12, 0, RSP_R1b, NULL);
             return true;
         }
-        address += (blocks * SD_BLOCK_SIZE);
-        sector += (blocks * (p.card_type_block ? 1 : SD_BLOCK_SIZE));
+        sd_cmd(12, 0, RSP_R1b, NULL);
+        address += (blocks * SD_SECTOR_SIZE);
+        sector += (blocks * (p.card_type_block ? 1 : SD_SECTOR_SIZE));
         count -= blocks;
     }
 
@@ -385,7 +393,7 @@ bool sd_read_sectors (uint32_t address, uint32_t sector, uint32_t count) {
     }
 
     if (!p.card_type_block) {
-        sector *= SD_BLOCK_SIZE;
+        sector *= SD_SECTOR_SIZE;
     }
 
     while (count > 0) {
@@ -406,8 +414,8 @@ bool sd_read_sectors (uint32_t address, uint32_t sector, uint32_t count) {
             }
             return true;
         }
-        address += (blocks * SD_BLOCK_SIZE);
-        sector += (blocks * (p.card_type_block ? 1 : SD_BLOCK_SIZE));
+        address += (blocks * SD_SECTOR_SIZE);
+        sector += (blocks * (p.card_type_block ? 1 : SD_SECTOR_SIZE));
         count -= blocks;
     }
 
diff --git a/sw/controller/src/sd.h b/sw/controller/src/sd.h
index 5648d8d..54d8dd3 100644
--- a/sw/controller/src/sd.h
+++ b/sw/controller/src/sd.h
@@ -5,6 +5,9 @@
 #include <stdbool.h>
 
 
+#define SD_SECTOR_SIZE      (512)
+
+
 bool sd_card_init (void);
 void sd_card_deinit (void);
 bool sd_card_get_status (void);
diff --git a/sw/pc/dd64.py b/sw/pc/dd64.py
index 2af1d6c..bd1e75b 100755
--- a/sw/pc/dd64.py
+++ b/sw/pc/dd64.py
@@ -185,6 +185,9 @@ class DD64Image:
             self.__file.close()
         self.__drive_type = None
 
+    def get_block_info_table(self) -> list[tuple[int, int]]:
+        return self.__block_info_table
+
     def get_drive_type(self) -> str:
         return self.__drive_type
 
@@ -222,6 +225,12 @@ if __name__ == '__main__':
                 print(dd.read_block(track, head, block)[:4])
             except BadBlockError:
                 print(f'Bad ID block [track: {track}, head: {head}, block: {block}]')
+        if (len(sys.argv) >= 3):
+            with open(sys.argv[2], 'wb+') as f:
+                block_info_table = dd.get_block_info_table()
+                for block in block_info_table:
+                    offset = 0xFFFFFFFF if block == None else block[0]
+                    f.write(offset.to_bytes(4, byteorder='big'))
         dd.unload()
     else:
         print(f'[{sys.argv[0]}]: Expected disk image path as first argument')
diff --git a/sw/pc/sc64.py b/sw/pc/sc64.py
index 3c77c63..58c21a6 100755
--- a/sw/pc/sc64.py
+++ b/sw/pc/sc64.py
@@ -238,6 +238,7 @@ class SC64:
         BUTTON_STATE = 12
         BUTTON_MODE = 13
         ROM_EXTENDED_ENABLE = 14
+        DD_SD_MODE = 15
 
     class __UpdateError(IntEnum):
         OK = 0
@@ -364,6 +365,7 @@ class SC64:
         self.__set_config(self.__CfgId.DD_DISK_STATE, self.__DDDiskState.EJECTED)
         self.__set_config(self.__CfgId.BUTTON_MODE, self.__ButtonMode.NONE)
         self.__set_config(self.__CfgId.ROM_EXTENDED_ENABLE, False)
+        self.__set_config(self.__CfgId.DD_SD_MODE, False)
         self.set_cic_parameters()
 
     def get_state(self):
@@ -383,6 +385,7 @@ class SC64:
             'button_state': bool(self.__get_config(self.__CfgId.BUTTON_STATE)),
             'button_mode': self.__ButtonMode(self.__get_config(self.__CfgId.BUTTON_MODE)),
             'rom_extended_enable': bool(self.__get_config(self.__CfgId.ROM_EXTENDED_ENABLE)),
+            'dd_sd_mode': bool(self.__get_config(self.__CfgId.DD_SD_MODE)),
         }
 
     def download_memory(self) -> bytes:
@@ -564,6 +567,7 @@ class SC64:
                     break
             if (dd):
                 self.__set_config(self.__CfgId.DD_MODE, self.__DDMode.FULL)
+                self.__set_config(self.__CfgId.DD_SD_MODE, False)
                 self.__set_config(self.__CfgId.DD_DRIVE_TYPE, {
                     'retail': self.__DDDriveType.RETAIL,
                     'development': self.__DDDriveType.DEVELOPMENT