diff --git a/README.md b/README.md
index 9a834fb..6daa88e 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@
  - 8 kB on-chip buffer for general use
  - 25 MB/s peak transfer rate USB interface for data upload/download and debug functionality
  - 25 MB/s peak transfer rate SD card interface
- - EEPROM, SRAM and FlashRAM save types ~~with automatic writeback to SD card~~ (_not implemented yet_)
+ - EEPROM, SRAM and FlashRAM save types with automatic writeback to SD card
  - Battery backed real time clock (RTC)
  - Status LED and button for general use
  - 64DD add-on emulation
diff --git a/sw/bootloader/src/sc64.c b/sw/bootloader/src/sc64.c
index b452878..aaf7683 100644
--- a/sw/bootloader/src/sc64.c
+++ b/sw/bootloader/src/sc64.c
@@ -19,7 +19,8 @@ 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',
+    SC64_CMD_DD_SD_INFO         = 'D',
+    SC64_CMD_WRITEBACK_SD_INFO  = 'W',
     SC64_CMD_FLASH_ERASE_BLOCK  = 'P',
     SC64_CMD_FLASH_WAIT_BUSY    = 'p',
 } cmd_id_t;
@@ -203,9 +204,17 @@ 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 length) {
+bool sc64_dd_set_sd_info (uint32_t *address, uint32_t length) {
     uint32_t args[2] = { (uint32_t) (address), length };
-    if (sc64_execute_cmd(SC64_CMD_DD_SD_DISK_INFO, args, NULL)) {
+    if (sc64_execute_cmd(SC64_CMD_DD_SD_INFO, args, NULL)) {
+        return true;
+    }
+    return false;
+}
+
+bool sc64_writeback_set_sd_info (uint32_t *address, bool enabled) {
+    uint32_t args[2] = { (uint32_t) (address), (uint32_t) (enabled) };
+    if (sc64_execute_cmd(SC64_CMD_WRITEBACK_SD_INFO, args, NULL)) {
         return true;
     }
     return false;
diff --git a/sw/bootloader/src/sc64.h b/sw/bootloader/src/sc64.h
index 70e5e9e..4feb948 100644
--- a/sw/bootloader/src/sc64.h
+++ b/sw/bootloader/src/sc64.h
@@ -117,6 +117,7 @@ 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 length);
+bool sc64_writeback_set_sd_info (uint32_t *address, bool enabled);
 
 
 #endif
diff --git a/sw/controller/app.mk b/sw/controller/app.mk
index c43df45..bf5870b 100644
--- a/sw/controller/app.mk
+++ b/sw/controller/app.mk
@@ -20,8 +20,10 @@ SRC_FILES = \
 	rtc.c \
 	sd.c \
 	task.c \
+	timer.c \
 	update.c \
-	usb.c
+	usb.c \
+	writeback.c
 PAD_TO = 0x08008000
 
 include common.mk
diff --git a/sw/controller/src/cfg.c b/sw/controller/src/cfg.c
index 8481e84..1044bfc 100644
--- a/sw/controller/src/cfg.c
+++ b/sw/controller/src/cfg.c
@@ -7,6 +7,7 @@
 #include "rtc.h"
 #include "sd.h"
 #include "usb.h"
+#include "writeback.h"
 
 
 typedef enum {
@@ -552,7 +553,15 @@ void cfg_process (void) {
                     cfg_set_error(CFG_ERROR_BAD_ADDRESS);
                     return;
                 }
-                dd_set_sd_disk_info(args[0], args[1]);
+                dd_set_sd_info(args[0], args[1]);
+                break;
+
+            case 'W':
+                if (cfg_translate_address(&args[0], 1024, (SDRAM | BRAM))) {
+                    cfg_set_error(CFG_ERROR_BAD_ADDRESS);
+                    return;
+                }
+                writeback_set_sd_info(args[0], args[1]);
                 break;
 
             case 'p':
diff --git a/sw/controller/src/dd.c b/sw/controller/src/dd.c
index 43f2ef0..b3dee08 100644
--- a/sw/controller/src/dd.c
+++ b/sw/controller/src/dd.c
@@ -268,7 +268,7 @@ void dd_set_sd_mode (bool value) {
     p.sd_mode = value;
 }
 
-void dd_set_sd_disk_info (uint32_t address, uint32_t length) {
+void dd_set_sd_info (uint32_t address, uint32_t length) {
     sd_disk_info_t info;
     length /= sizeof(info);
     p.sd_current_disk = 0;
@@ -313,7 +313,7 @@ void dd_init (void) {
     p.drive_type = DD_DRIVE_TYPE_RETAIL;
     p.sd_mode = false;
     p.sd_current_disk = 0;
-    dd_set_sd_disk_info(0, 0);
+    dd_set_sd_info(0, 0);
 }
 
 void dd_process (void) {
diff --git a/sw/controller/src/dd.h b/sw/controller/src/dd.h
index 3bddaff..df5114d 100644
--- a/sw/controller/src/dd.h
+++ b/sw/controller/src/dd.h
@@ -25,7 +25,7 @@ dd_disk_state_t dd_get_disk_state (void);
 bool dd_set_disk_state (dd_disk_state_t state);
 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_set_sd_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/gvr.c b/sw/controller/src/gvr.c
index bdc836a..0dc6cf7 100644
--- a/sw/controller/src/gvr.c
+++ b/sw/controller/src/gvr.c
@@ -7,6 +7,7 @@
 #include "rtc.h"
 #include "sd.h"
 #include "usb.h"
+#include "writeback.h"
 
 
 void gvr_task (void) {
@@ -19,6 +20,7 @@ void gvr_task (void) {
     isv_init();
     sd_init();
     usb_init();
+    writeback_init();
 
     while (1) {
         button_process();
@@ -29,5 +31,6 @@ void gvr_task (void) {
         rtc_process();
         sd_process();
         usb_process();
+        writeback_process();
     }
 }
diff --git a/sw/controller/src/led.c b/sw/controller/src/led.c
index 73178d3..ba5cd69 100644
--- a/sw/controller/src/led.c
+++ b/sw/controller/src/led.c
@@ -2,6 +2,7 @@
 #include "hw.h"
 #include "led.h"
 #include "task.h"
+#include "timer.h"
 
 
 #define LED_MS_PER_TICK         (10)
@@ -113,6 +114,8 @@ void led_blink_act (void) {
 }
 
 void led_task (void) {
+    timer_init();
+
     while (1) {
         hw_tim_setup(TIM_ID_LED, LED_MS_PER_TICK, led_task_resume);
 
@@ -124,6 +127,8 @@ void led_task (void) {
             led_process_act();
         }
 
+        timer_update();
+
         task_yield();
     }
 }
diff --git a/sw/controller/src/timer.c b/sw/controller/src/timer.c
new file mode 100644
index 0000000..03d44a5
--- /dev/null
+++ b/sw/controller/src/timer.c
@@ -0,0 +1,30 @@
+#include "hw.h"
+#include "timer.h"
+
+
+static volatile uint32_t timer[__TIMER_ID_COUNT];
+
+
+uint32_t timer_get (timer_id_t id) {
+    return (uint32_t) (timer[id]);
+}
+
+void timer_set (timer_id_t id, uint32_t ticks) {
+    hw_tim_disable_irq(TIM_ID_LED);
+    timer[id] = ticks;
+    hw_tim_enable_irq(TIM_ID_LED);
+}
+
+void timer_init (void) {
+    for (timer_id_t id = 0; id < __TIMER_ID_COUNT; id++) {
+        timer[id] = 0;
+    }
+}
+
+void timer_update (void) {
+    for (timer_id_t id = 0; id < __TIMER_ID_COUNT; id++) {
+        if (timer[id] > 0) {
+            timer[id] -= 1;
+        }
+    }
+}
diff --git a/sw/controller/src/timer.h b/sw/controller/src/timer.h
new file mode 100644
index 0000000..e9f480d
--- /dev/null
+++ b/sw/controller/src/timer.h
@@ -0,0 +1,20 @@
+#ifndef TIMER_H__
+#define TIMER_H__
+
+
+#include <stdint.h>
+
+
+typedef enum {
+    TIMER_ID_WRITEBACK,
+    __TIMER_ID_COUNT
+} timer_id_t;
+
+
+uint32_t timer_get (timer_id_t id);
+void timer_set (timer_id_t id, uint32_t ticks);
+void timer_init (void);
+void timer_update (void);
+
+
+#endif
diff --git a/sw/controller/src/writeback.c b/sw/controller/src/writeback.c
new file mode 100644
index 0000000..c21cf84
--- /dev/null
+++ b/sw/controller/src/writeback.c
@@ -0,0 +1,82 @@
+#include "fpga.h"
+#include "sd.h"
+#include "timer.h"
+#include "writeback.h"
+#include "led.h"
+
+
+#define SAVE_MAX_SECTOR_COUNT   (256)
+#define SRAM_FLASHRAM_ADDRESS   (0x03FE0000)
+#define EEPROM_ADDRESS          (0x05002000)
+#define WRITEBACK_DELAY_TICKS   (100)
+
+
+struct process {
+    bool enabled;
+    bool pending;
+    uint16_t last_save_count;
+    uint32_t sectors[SAVE_MAX_SECTOR_COUNT];
+};
+
+
+static struct process p;
+
+
+static void writeback_save_to_sd (void) {
+    uint32_t save_address = SRAM_FLASHRAM_ADDRESS;
+    if (fpga_reg_get(REG_CFG_SCR) & CFG_SCR_EEPROM_ENABLED) {
+        save_address = EEPROM_ADDRESS;
+    }
+    for (int i = 0; i < SAVE_MAX_SECTOR_COUNT; i++) {
+        uint32_t sector = p.sectors[i];
+        if (sector == 0) {
+            break;
+        }
+        if (sd_write_sectors(save_address, sector, 1)) {
+            break;
+        }
+        save_address += SD_SECTOR_SIZE;
+    }
+}
+
+
+void writeback_set_sd_info (uint32_t address, bool enabled) {
+    p.enabled = enabled;
+    p.pending = false;
+    p.last_save_count = fpga_reg_get(REG_SAVE_COUNT);
+    if (p.enabled) {
+        fpga_mem_read(address, sizeof(p.sectors), (uint8_t *) (p.sectors));
+        for (int i = 0; i < SAVE_MAX_SECTOR_COUNT; i++) {
+            p.sectors[i] = SWAP32(p.sectors[i]);
+        }
+    } else {
+        for (int i = 0; i < SAVE_MAX_SECTOR_COUNT; i++) {
+            p.sectors[i] = 0;
+        }
+    }
+}
+
+void writeback_init (void) {
+    p.enabled = false;
+    p.pending = false;
+    for (int i = 0; i < SAVE_MAX_SECTOR_COUNT; i++) {
+        p.sectors[i] = 0;
+    }
+}
+
+void writeback_process (void) {
+    if (p.enabled) {
+        uint16_t save_count = fpga_reg_get(REG_SAVE_COUNT);
+        if (save_count != p.last_save_count) {
+            p.pending = true;
+            timer_set(TIMER_ID_WRITEBACK, WRITEBACK_DELAY_TICKS);
+            p.last_save_count = save_count;
+        }
+    }
+    if (p.pending) {
+        if (timer_get(TIMER_ID_WRITEBACK) == 0) {
+            p.pending = false;
+            writeback_save_to_sd();
+        }
+    }
+}
diff --git a/sw/controller/src/writeback.h b/sw/controller/src/writeback.h
new file mode 100644
index 0000000..3895121
--- /dev/null
+++ b/sw/controller/src/writeback.h
@@ -0,0 +1,14 @@
+#ifndef WRITEBACK_H__
+#define WRITEBACK_H__
+
+
+#include <stdbool.h>
+#include <stdint.h>
+
+
+void writeback_set_sd_info (uint32_t address, bool enabled);
+void writeback_init (void);
+void writeback_process (void);
+
+
+#endif