diff --git a/Makefile b/Makefile
index 9c597a3..39a09f3 100644
--- a/Makefile
+++ b/Makefile
@@ -228,6 +228,9 @@ include $(RULESPATH)/rules.mk
 flash: build/ch.bin
 	dfu-util -d 0483:df11 -a 0 -s 0x08000000:leave -D build/ch.bin
 
+dfu:
+	printf "reset dfu\r" >/dev/cu.usbmodem401
+
 TAGS: Makefile
 	@etags *.[ch] NANOVNA_STM32_F072/*.[ch] $(shell find ChibiOS/os/hal/ports/STM32/STM32F0xx ChibiOS/os -name \*.\[ch\] -print) 
 	@ls -l TAGS
diff --git a/NANOVNA_STM32_F072/board.c b/NANOVNA_STM32_F072/board.c
index bcf8f8a..f7d2f0e 100644
--- a/NANOVNA_STM32_F072/board.c
+++ b/NANOVNA_STM32_F072/board.c
@@ -70,6 +70,21 @@ const PALConfig pal_default_config = {
  * any other initialization.
  */
 void __early_init(void) {
+  if ( *((unsigned long *)BOOT_FROM_SYTEM_MEMORY_MAGIC_ADDRESS) == BOOT_FROM_SYTEM_MEMORY_MAGIC ) {
+    // require irq
+    __enable_irq();
+    // reset magic bytes
+    *((unsigned long *)BOOT_FROM_SYTEM_MEMORY_MAGIC_ADDRESS) = 0;
+    // remap memory. unneeded for F072?
+    // RCC->APB2ENR |= RCC_APB2ENR_SYSCFGEN;
+    // SYSCFG->CFGR1 = 0x01;
+    // set msp for system memory
+    __set_MSP(SYSTEM_BOOT_MSP); 
+    // jump to system memory
+    ( (void (*)(void)) (*((uint32_t *)(STM32F072xB_SYSTEM_MEMORY+4))) )();
+    while (1);
+  }
+
   //si5351_setup();
   stm32_clock_init();
 }
diff --git a/NANOVNA_STM32_F072/board.h b/NANOVNA_STM32_F072/board.h
index 5c9e0e4..7ab4c29 100644
--- a/NANOVNA_STM32_F072/board.h
+++ b/NANOVNA_STM32_F072/board.h
@@ -40,6 +40,11 @@
  */
 #define STM32F072xB
 
+#define STM32F072xB_SYSTEM_MEMORY 0x1FFFC800
+#define BOOT_FROM_SYTEM_MEMORY_MAGIC_ADDRESS 0x20003FF0
+#define BOOT_FROM_SYTEM_MEMORY_MAGIC 0xDEADBEEF
+#define SYSTEM_BOOT_MSP 0x20002250
+
 /*
  * IO pins assignments
  */
diff --git a/ili9341.c b/ili9341.c
index 6fbb2c4..e42d6de 100644
--- a/ili9341.c
+++ b/ili9341.c
@@ -360,6 +360,34 @@ ili9341_drawstring_5x7(const char *str, int x, int y, uint16_t fg, uint16_t bg)
   }
 }
 
+void
+ili9341_drawchar_size(uint8_t ch, int x, int y, uint16_t fg, uint16_t bg, uint8_t size)
+{
+  uint16_t *buf = spi_buffer;
+  uint16_t bits;
+  int c, r;
+  for(c = 0; c < 7*size; c++) {
+    bits = x5x7_bits[(ch * 7) + (c / size)];
+    for (r = 0; r < 5*size; r++) {
+      *buf++ = (0x8000 & bits) ? fg : bg;
+      if (r % size == (size-1)) {
+          bits <<= 1;
+      }
+    }
+  }
+  ili9341_bulk(x, y, 5*size, 7*size);
+}
+
+void
+ili9341_drawstring_size(const char *str, int x, int y, uint16_t fg, uint16_t bg, uint8_t size)
+{
+  while (*str) {
+    ili9341_drawchar_size(*str, x, y, fg, bg, size);
+    x += 5 * size;
+    str++;
+  }
+}
+
 #define SWAP(x,y) do { int z=x; x = y; y = z; } while(0)
 
 void
diff --git a/main.c b/main.c
index 6312d04..06ef386 100644
--- a/main.c
+++ b/main.c
@@ -130,6 +130,14 @@ static void cmd_reset(BaseSequentialStream *chp, int argc, char *argv[])
     (void)argc;
     (void)argv;
 
+    if (argc == 1) {
+        if (strcmp(argv[0], "dfu") == 0) {
+            chprintf(chp, "Performing reset to DFU mode\r\n");
+            enter_dfu();
+            return;
+        }
+    }
+
     chprintf(chp, "Performing reset\r\n");
 
     rccEnableWWDG(FALSE);
@@ -400,8 +408,6 @@ static void cmd_capture(BaseSequentialStream *chp, int argc, char *argv[])
     (void)argc;
     (void)argv;
 
-    chMtxLock(&mutex);
-
     // pause sweep
     stop_the_world = TRUE;
 
@@ -429,7 +435,6 @@ static void cmd_capture(BaseSequentialStream *chp, int argc, char *argv[])
     //*/
 
     stop_the_world = FALSE;
-    chMtxUnlock(&mutex);
 }
 
 #if 0
diff --git a/nanovna.h b/nanovna.h
index ba5a947..4ddebe4 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -254,6 +254,8 @@ void ili9341_bulk(int x, int y, int w, int h);
 void ili9341_fill(int x, int y, int w, int h, int color);
 void ili9341_drawchar_5x7(uint8_t ch, int x, int y, uint16_t fg, uint16_t bg);
 void ili9341_drawstring_5x7(const char *str, int x, int y, uint16_t fg, uint16_t bg);
+void ili9341_drawchar_size(uint8_t ch, int x, int y, uint16_t fg, uint16_t bg, uint8_t size);
+void ili9341_drawstring_size(const char *str, int x, int y, uint16_t fg, uint16_t bg, uint8_t size);
 void ili9341_drawfont(uint8_t ch, const font_t *font, int x, int y, uint16_t fg, uint16_t bg);
 void ili9341_read_memory(int x, int y, int w, int h, int len, uint16_t* out);
 void ili9341_read_memory_continue(int len, uint16_t* out);
@@ -337,6 +339,7 @@ void handle_touch_interrupt(void);
 
 void touch_cal_exec(void);
 void touch_draw_test(void);
+void enter_dfu(void);
 
 /*
  * adc.c
diff --git a/ui.c b/ui.c
index 9e7f090..0012db5 100644
--- a/ui.c
+++ b/ui.c
@@ -383,6 +383,53 @@ touch_position(int *x, int *y)
 }
 
 
+void
+show_version(void)
+{
+  int status;
+  int x = 5, y = 5;
+  int i;
+  
+  adc_stop(ADC1);
+  ili9341_fill(0, 0, 320, 240, 0);
+
+  ili9341_drawstring_size(BOARD_NAME, x, y, 0xffff, 0x0000, 4);
+  y += 25;
+
+  ili9341_drawstring_5x7("2016-2019 Copyright @edy555", x, y += 10, 0xffff, 0x0000);
+  ili9341_drawstring_5x7("Licensed under GPL. See: https://github.com/ttrftech/NanoVNA", x, y += 10, 0xffff, 0x0000);
+  ili9341_drawstring_5x7("Version: " VERSION, x, y += 10, 0xffff, 0x0000);
+  ili9341_drawstring_5x7("Build Time: " __DATE__ " - " __TIME__, x, y += 10, 0xffff, 0x0000);
+  y += 5;
+  ili9341_drawstring_5x7("Kernel: " CH_KERNEL_VERSION, x, y += 10, 0xffff, 0x0000);
+  ili9341_drawstring_5x7("Compiler: " PORT_COMPILER_NAME, x, y += 10, 0xffff, 0x0000);
+  ili9341_drawstring_5x7("Architecture: " PORT_ARCHITECTURE_NAME " Core Variant: " PORT_CORE_VARIANT_NAME, x, y += 10, 0xffff, 0x0000);
+  ili9341_drawstring_5x7("Port Info: " PORT_INFO, x, y += 10, 0xffff, 0x0000);
+  ili9341_drawstring_5x7("Platform: " PLATFORM_NAME, x, y += 10, 0xffff, 0x0000);
+
+  do {
+    status = touch_check();
+  } while(status != EVT_TOUCH_PRESSED);
+
+  touch_start_watchdog();
+}
+
+void
+enter_dfu(void)
+{
+  adc_stop(ADC1);
+
+  int x = 5, y = 5;
+
+  // leave a last message 
+  ili9341_fill(0, 0, 320, 240, 0);
+  ili9341_drawstring_5x7("DFU: Device Firmware Update Mode", x, y += 10, 0xffff, 0x0000);
+  ili9341_drawstring_5x7("To exit DFU mode, please reset device yourself.", x, y += 10, 0xffff, 0x0000);
+
+  // see __early_init in ./NANOVNA_STM32_F072/board.c
+  *((unsigned long *)BOOT_FROM_SYTEM_MEMORY_MAGIC_ADDRESS) = BOOT_FROM_SYTEM_MEMORY_MAGIC;
+  NVIC_SystemReset();
+}
 
 
 // type of menu item 
@@ -490,6 +537,20 @@ menu_config_cb(int item)
       menu_move_back();
       ui_mode_normal();
       break;
+  case 3:
+      show_version();
+      redraw_frame();
+      request_to_redraw_grid();
+      draw_menu();
+  }
+}
+
+static void
+menu_dfu_cb(int item)
+{
+  switch (item) {
+  case 0:
+      enter_dfu();
   }
 }
 
@@ -863,10 +924,18 @@ const menuitem_t menu_recall[] = {
   { MT_NONE, NULL, NULL } // sentinel
 };
 
+const menuitem_t menu_dfu[] = {
+  { MT_CALLBACK, "\2RESET AND\0ENTER DFU", menu_dfu_cb },
+  { MT_CANCEL, S_LARROW"CANCEL", NULL },
+  { MT_NONE, NULL, NULL } // sentinel
+};
+
 const menuitem_t menu_config[] = {
   { MT_CALLBACK, "TOUCH CAL", menu_config_cb },
   { MT_CALLBACK, "TOUCH TEST", menu_config_cb },
   { MT_CALLBACK, "SAVE", menu_config_cb },
+  { MT_CALLBACK, "VERSION", menu_config_cb },
+  { MT_SUBMENU, S_RARROW"DFU", menu_dfu },
   { MT_CANCEL, S_LARROW" BACK", NULL },
   { MT_NONE, NULL, NULL } // sentinel
 };
@@ -1119,6 +1188,9 @@ draw_numeric_input(const char *buf)
       x += xsim[i];
     }
   }
+  if (i < 10) {
+      ili9341_fill(x, 208+4, 20*(10-i), 24, 0xffff);
+  }
 }
 
 static int