diff --git a/Makefile b/Makefile
index 371a9fc..a5ea305 100644
--- a/Makefile
+++ b/Makefile
@@ -100,7 +100,8 @@ include $(CHIBIOS)/os/hal/lib/streams/streams.mk
 include $(CHIBIOS)/os/various/shell/shell.mk
 
 # Define linker script file here
-LDSCRIPT= $(STARTUPLD)/STM32F072xB.ld
+#LDSCRIPT= $(STARTUPLD)/STM32F072xB.ld
+LDSCRIPT= STM32F072xB.ld
 
 CMSIS = CMSIS
 DSPLIBINC = ${CMSIS}/Include
@@ -119,7 +120,7 @@ CSRC = $(STARTUPSRC) \
        $(SHELLSRC) \
        $(DSPLIBSRC) \
        usbcfg.c \
-       main.c si5351.c si5351_low.c tlv320aic3204.c dsp.c ili9431.c numfont20x24.c Font5x7.c
+       main.c si5351.c si5351_low.c tlv320aic3204.c dsp.c ili9431.c numfont20x24.c Font5x7.c flash.c
 
 #       $(TESTSRC) \
 
diff --git a/ili9431.c b/ili9431.c
index 625b2e6..56ecc24 100644
--- a/ili9431.c
+++ b/ili9431.c
@@ -420,7 +420,7 @@ ili9341_test(int mode)
 
 
 
-int prev_x;
+//int prev_x;
 
 int32_t fstart = 0;
 int32_t fstop = 300000000;
diff --git a/main.c b/main.c
index af16942..5fcb865 100644
--- a/main.c
+++ b/main.c
@@ -216,10 +216,6 @@ int16_t dump_selection = 0;
 
 int16_t dsp_disabled = FALSE;
 float measured[2][101][2];
-uint32_t frequencies[101];
-
-uint16_t cal_status;
-float cal_data[5][101][2];
 
 
 
@@ -311,11 +307,30 @@ static void cmd_gamma(BaseSequentialStream *chp, int argc, char *argv[])
   chprintf(chp, "%d %d\r\n", gamma[0], gamma[1]);
 }
 
-
+#if 0
 int32_t freq_start = 1000000;
 int32_t freq_stop = 300000000;
 int16_t sweep_points = 101;
 
+uint32_t frequencies[101];
+uint16_t cal_status;
+float cal_data[5][101][2];
+#endif
+
+config_t current_config = {
+  /* magic */   CONFIG_MAGIC,
+  /* freq_start */   1000000,
+  /* freq_stop */  300000000,
+  /* sweep_points */     101,
+  /* cal_status */         0,
+  /* frequencies */       {},
+  /* cal_data */          {},
+  /* checksum */           0
+};
+config_t *active = &current_config;
+
+
+
 static void cmd_scan(BaseSequentialStream *chp, int argc, char *argv[])
 {
   float gamma[2];
@@ -653,6 +668,22 @@ static void cmd_cal(BaseSequentialStream *chp, int argc, char *argv[])
   }
 }
 
+static void cmd_save(BaseSequentialStream *chp, int argc, char *argv[])
+{
+  (void)chp;
+  (void)argc;
+  (void)argv;
+  caldata_save();
+}
+
+static void cmd_recall(BaseSequentialStream *chp, int argc, char *argv[])
+{
+  (void)chp;
+  (void)argc;
+  (void)argv;
+  caldata_recall();
+}
+
 static void cmd_test(BaseSequentialStream *chp, int argc, char *argv[])
 {
   int i;
@@ -777,6 +808,8 @@ static const ShellCommand commands[] =
     { "pause", cmd_pause },
     { "resume", cmd_resume },
     { "cal", cmd_cal },
+    { "save", cmd_save },
+    { "recall", cmd_recall },
     { NULL, NULL }
 };
 
@@ -829,6 +862,9 @@ int main(void)
    * SPI LCD Initialize
    */
   ili9341_init();
+
+  caldata_recall();
+
   set_sweep(freq_start, freq_stop);
   redraw();
 
diff --git a/nanovna.h b/nanovna.h
index 852fe25..feb4f22 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -87,3 +87,29 @@ void draw_cell_all(void);
 extern const uint16_t x5x7_bits [];
 extern const uint32_t numfont20x24[][24];
 
+int caldata_save(void);
+int caldata_recall(void);
+
+typedef struct {
+  int32_t magic;
+  int32_t _freq_start;
+  int32_t _freq_stop;
+  int16_t _sweep_points;
+  uint16_t _cal_status;
+
+  uint32_t _frequencies[101];
+  float _cal_data[5][101][2];
+  int32_t checksum;
+} config_t;
+
+#define CONFIG_MAGIC 0x436f4e45 /* 'CoNF' */
+
+extern config_t *active;
+extern config_t current_config;
+
+#define freq_start active->_freq_start
+#define freq_stop active->_freq_stop
+#define sweep_points active->_sweep_points
+#define cal_status active->_cal_status
+#define frequencies active->_frequencies
+#define cal_data active->_cal_data