diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3d9277e..7fa43d7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -113,7 +113,7 @@ set(SOURCE_FILES
         user/cgi_sockets.h
         user/ansi_parser_callbacks.c
         user/ansi_parser_callbacks.h
-        user/user_main.h user/wifi_manager.c user/wifi_manager.h)
+        user/user_main.h user/wifimgr.c user/wifimgr.h user/persist.c user/persist.h)
 
 include_directories(include)
 include_directories(user)
diff --git a/user/persist.c b/user/persist.c
new file mode 100644
index 0000000..381b266
--- /dev/null
+++ b/user/persist.c
@@ -0,0 +1,192 @@
+//
+// Created by MightyPork on 2017/07/09.
+//
+
+#include "persist.h"
+#include <esp8266.h>
+#include "wifimgr.h"
+#include "screen.h"
+
+FullPersistBlock persist;
+
+#define PERSIST_SECTOR_ID 0x3D
+
+//region Persist and restore individual modules
+
+/**
+ * Load persistent settings to live config structs
+ */
+static void ICACHE_FLASH_ATTR
+load_settings_to_live(void)
+{
+	dbg("[Persist] Loading current settings to modules...");
+	memcpy(&wificonf, &persist.current.wificonf, sizeof(WiFiConfigBlock));
+	memcpy(&termconf, &persist.current.termconf, sizeof(TerminalConfigBlock));
+	// ...
+}
+
+static void ICACHE_FLASH_ATTR
+store_settings_from_live(void)
+{
+	dbg("[Persist] Collecting live settings to persist block...");
+	memcpy(&persist.current.wificonf, &wificonf, sizeof(wificonf));
+	memcpy(&persist.current.termconf, &termconf, sizeof(termconf));
+	// ...
+}
+
+static void ICACHE_FLASH_ATTR
+apply_live_settings(void)
+{
+	dbg("[Persist] Applying live settings...");
+	terminal_apply_settings();
+	wifimgr_apply_settings();
+	// ...
+}
+
+static void ICACHE_FLASH_ATTR
+restore_live_settings_to_hard_defaults(void)
+{
+	wifimgr_restore_defaults();
+	terminal_restore_defaults();
+	// ...
+}
+
+//endregion
+
+/**
+ * Compute CRC32. Adapted from https://github.com/esp8266/Arduino
+ * @param data
+ * @param length
+ * @return crc32
+ */
+static uint32_t ICACHE_FLASH_ATTR
+calculateCRC32(const uint8_t *data, size_t length)
+{
+	uint32_t crc = 0xffffffff;
+	while (length--) {
+		uint8_t c = *data++;
+		for (uint32_t i = 0x80; i > 0; i >>= 1) {
+			bool bit = (bool) (crc & 0x80000000UL);
+			if (c & i) {
+				bit = !bit;
+			}
+			crc <<= 1;
+			if (bit) {
+				crc ^= 0x04c11db7UL;
+			}
+		}
+	}
+	return crc;
+}
+
+/**
+ * Compute a persist bundle checksum
+ *
+ * @param bundle
+ * @return
+ */
+static uint32_t ICACHE_FLASH_ATTR
+compute_checksum(PersistBundle *bundle)
+{
+	return calculateCRC32((uint8_t *) bundle, sizeof(PersistBundle) - 4);
+}
+
+/**
+ * Load, verify and apply persistent config
+ */
+void ICACHE_FLASH_ATTR
+persist_load(void)
+{
+	info("[Persist] Loading stored settings from FLASH...");
+
+	bool hard_reset = false;
+
+	// Try to load
+	hard_reset |= !system_param_load(PERSIST_SECTOR_ID, 0, &persist, sizeof(persist));
+
+	// Verify checksums
+	if (hard_reset ||
+		(compute_checksum(&persist.defaults) != persist.defaults.checksum) ||
+		(compute_checksum(&persist.current) != persist.current.checksum)) {
+		error("[Persist] Config block failed to load, restoring to hard defaults.");
+		hard_reset = true;
+	}
+
+	if (hard_reset) {
+		persist_restore_hard_default();
+		// this also stores them to flash and applies to modues
+	} else {
+		load_settings_to_live();
+		apply_live_settings();
+	}
+
+	info("[Persist] All settings loaded and applied.");
+}
+
+void ICACHE_FLASH_ATTR
+persist_store(void)
+{
+	info("[Persist] Storing all settings to FLASH...");
+	store_settings_from_live();
+
+	// Update checksums before write
+	persist.current.checksum = compute_checksum(&persist.current);
+	persist.defaults.checksum = compute_checksum(&persist.defaults);
+
+	if (!system_param_save_with_protect(PERSIST_SECTOR_ID, &persist, sizeof(persist))) {
+		error("[Persist] Store to flash failed!");
+	}
+	info("[Persist] All settings persisted.");
+}
+
+/**
+ * Restore to built-in defaults
+ */
+void ICACHE_FLASH_ATTR
+persist_restore_hard_default(void)
+{
+	info("[Persist] Restoring all settings to hard defaults...");
+
+	// Set live config to default values
+	restore_live_settings_to_hard_defaults();
+
+	// Store live -> current
+	store_settings_from_live();
+
+	// Store current -> default
+	memcpy(&persist.defaults, &persist.current, sizeof(persist.current));
+	persist_store();
+
+	info("[Persist] All settings restored to hard defaults.");
+
+	apply_live_settings(); // apply
+}
+
+/**
+ * Restore default settings & apply
+ */
+void ICACHE_FLASH_ATTR
+persist_restore_default(void)
+{
+	info("[Persist] Restoring live settings to stored defaults...");
+	memcpy(&persist.current, &persist.defaults, sizeof(persist.defaults));
+	load_settings_to_live();
+	apply_live_settings();
+	info("[Persist] Settings restored to stored defaults.");
+}
+
+/**
+ * Store current settings as defaults & write to flash
+ */
+void ICACHE_FLASH_ATTR
+persist_set_as_default(void)
+{
+	info("[Persist] Storing live settings as defaults..");
+
+	store_settings_from_live();
+	memcpy(&persist.defaults, &persist.current, sizeof(persist.current));
+
+	persist_store();
+
+	info("[Persist] Default settings updated.");
+}
diff --git a/user/persist.h b/user/persist.h
new file mode 100644
index 0000000..197eaa6
--- /dev/null
+++ b/user/persist.h
@@ -0,0 +1,39 @@
+//
+// Created by MightyPork on 2017/07/09.
+//
+// There are 4 sets of settings.
+// - hard defaults - hardcoded in firmware, used for init defaults after flash or if stored data are corrupt
+// - defaults - persisted by privileged user
+// - current - persistent current config state, can be restored to defaults any time
+// - live - non-persistent settings valid only for the current runtime
+
+#ifndef ESP_VT100_FIRMWARE_PERSIST_H
+#define ESP_VT100_FIRMWARE_PERSIST_H
+
+#include "wifimgr.h"
+#include "screen.h"
+
+typedef struct {
+	WiFiConfigBlock wificonf;
+	TerminalConfigBlock termconf;
+	// ...
+	// other settings here
+	// ...
+	uint32_t checksum; // computed before write and tested on load. If it doesn't match, values are reset to hard defaults.
+} PersistBundle;
+
+typedef struct {
+	PersistBundle defaults; // defaults are stored here
+	PersistBundle current;  // settings persisted by user
+} FullPersistBlock;
+
+// Persist holds the data currently loaded from the flash
+extern FullPersistBlock persist;
+
+void persist_load(void);
+void persist_restore_hard_default(void);
+void persist_restore_default(void);
+void persist_set_as_default(void);
+void persist_store(void);
+
+#endif //ESP_VT100_FIRMWARE_PERSIST_H
diff --git a/user/screen.c b/user/screen.c
index 54fd004..90f3fbc 100644
--- a/user/screen.c
+++ b/user/screen.c
@@ -4,6 +4,36 @@
 
 //region Data structures
 
+TerminalConfigBlock termconf;
+
+/**
+ * Restore hard defaults
+ */
+void terminal_restore_defaults(void)
+{
+	termconf.default_bg = 0;
+	termconf.default_fg = 7;
+	termconf.width = 26;
+	termconf.height = 10;
+	sprintf(termconf.title, "ESP8266 Wireless Terminal");
+	sprintf(termconf.btn1, "1");
+	sprintf(termconf.btn2, "2");
+	sprintf(termconf.btn3, "3");
+	sprintf(termconf.btn4, "4");
+	sprintf(termconf.btn5, "5");
+}
+
+/**
+ * Apply settings after eg. restore from defaults
+ */
+void terminal_apply_settings(void)
+{
+	screen_init();
+}
+
+#define W termconf.width
+#define H termconf.height
+
 /**
  * Highest permissible value of the color attribute
  */
@@ -50,16 +80,6 @@ static struct {
 	Color bg;
 } cursor_sav;
 
-/**
- * Active screen width
- */
-static int W = SCREEN_DEF_W;
-
-/**
- * Active screen height
- */
-static int H = SCREEN_DEF_H;
-
 // XXX volatile is probably not needed
 static volatile int notifyLock = 0;
 
@@ -99,8 +119,8 @@ cursor_reset(void)
 {
 	cursor.x = 0;
 	cursor.y = 0;
-	cursor.fg = SCREEN_DEF_FG;
-	cursor.bg = SCREEN_DEF_BG;
+	cursor.fg = termconf.default_fg;
+	cursor.bg = termconf.default_bg;
 	cursor.visible = 1;
 	cursor.inverse = 0;
 	cursor.autowrap = 1;
@@ -363,8 +383,8 @@ screen_cursor_save(bool withAttrs)
 		cursor_sav.bg = cursor.bg;
 		cursor_sav.inverse = cursor.inverse;
 	} else {
-		cursor_sav.fg = SCREEN_DEF_FG;
-		cursor_sav.bg = SCREEN_DEF_BG;
+		cursor_sav.fg = termconf.default_fg;
+		cursor_sav.bg = termconf.default_bg;
 		cursor_sav.inverse = 0;
 	}
 }
diff --git a/user/screen.h b/user/screen.h
index 701e759..36ab637 100644
--- a/user/screen.h
+++ b/user/screen.h
@@ -34,6 +34,25 @@
  *
  */
 
+typedef struct {
+	u32 width;
+	u32 height;
+	u8 default_bg;
+	u8 default_fg;
+	char title[64];
+	char btn1[10];
+	char btn2[10];
+	char btn3[10];
+	char btn4[10];
+	char btn5[10];
+} TerminalConfigBlock;
+
+// Live config
+extern TerminalConfigBlock termconf;
+
+void terminal_restore_defaults(void);
+void terminal_apply_settings(void);
+
 /**
  * Maximum screen size (determines size of the static data array)
  *
@@ -42,20 +61,13 @@
  */
 #define MAX_SCREEN_SIZE (80*25)
 
-#define SCREEN_DEF_W 26  //!< Default screen width
-#define SCREEN_DEF_H 10  //!< Default screen height
-
-#define SCREEN_DEF_BG 0  //!< Default screen background
-#define SCREEN_DEF_FG 7  //!< Default screen foreground
-
 typedef enum {
 	CLEAR_TO_CURSOR=0, CLEAR_FROM_CURSOR=1, CLEAR_ALL=2
 } ClearMode;
 
 typedef uint8_t Color;
 
-httpd_cgi_state ICACHE_FLASH_ATTR
-screenSerializeToBuffer(char *buffer, size_t buf_len, void **data);
+httpd_cgi_state screenSerializeToBuffer(char *buffer, size_t buf_len, void **data);
 
 /** Init the screen */
 void screen_init(void);
diff --git a/user/user_main.c b/user/user_main.c
index 0990b41..67c7762 100644
--- a/user/user_main.c
+++ b/user/user_main.c
@@ -26,7 +26,8 @@
 #include "user_main.h"
 #include "uart_driver.h"
 #include "ansi_parser_callbacks.h"
-#include "wifi_manager.h"
+#include "wifimgr.h"
+#include "persist.h"
 
 #ifdef ESPFS_POS
 CgiUploadFlashDef uploadParams={
@@ -48,9 +49,6 @@ CgiUploadFlashDef uploadParams={
 #define INCLUDE_FLASH_FNS
 #endif
 
-static ETSTimer prHeapTimer;
-static ETSTimer userStartTimer;
-
 /** Periodically show heap usage */
 static void ICACHE_FLASH_ATTR prHeapTimerCb(void *arg)
 {
@@ -79,42 +77,15 @@ static void ICACHE_FLASH_ATTR prHeapTimerCb(void *arg)
 	cnt++;
 }
 
-static void user_start(void *unused)
-{
-	// TODO load persistent data, init wificonf
-
-	// Change AP name if AI-THINKER found (means un-initialized device)
-	struct softap_config apconf;
-	wifi_softap_get_config(&apconf);
-	if (strstarts((char*)apconf.ssid, "AI-THINKER")) {
-		warn("Un-initialized device, performing factory reset.");
-		apars_handle_OSC_FactoryReset();
-		return;
-	}
-
-	// Set up WiFi & connect
-	wifimgr_restore_defaults();
-	wifimgr_apply_settings();
-
-	// Captive portal
-	captdnsInit();
-
-	// Server
-	httpdInit(routes, 80);
-
-	// The terminal screen
-	screen_init();
-
-	// Print the CANCEL character to indicate the module has restarted
-	// Critically important for client application if any kind of screen persistence / content re-use is needed
-	UART_WriteChar(UART0, 24, UART_TIMEOUT_US); // 0x18 - 24 - CAN
-
-	info("Listening on UART0, 115200-8-N-1!");
-}
+// Deferred init
+static void user_start(void *unused);
 
 //Main routine. Initialize stdout, the I/O, filesystem and the webserver and we're done.
 void ICACHE_FLASH_ATTR user_init(void)
 {
+	static ETSTimer userStartTimer;
+	static ETSTimer prHeapTimer;
+
 	serialInit();
 
 	// Prevent WiFi starting and connecting by default
@@ -147,12 +118,40 @@ void ICACHE_FLASH_ATTR user_init(void)
 	os_timer_setfn(&prHeapTimer, prHeapTimerCb, NULL);
 	os_timer_arm(&prHeapTimer, 1000, 1);
 
-	// do later (some functions do not yet work if called from user_init)
+	// do later (some functions do not work if called from user_init)
 	os_timer_disarm(&userStartTimer);
 	os_timer_setfn(&userStartTimer, user_start, NULL);
 	os_timer_arm(&userStartTimer, 10, 0);
 }
 
+static void user_start(void *unused)
+{
+	// Change AP name if AI-THINKER found (means un-initialized device)
+//	struct softap_config apconf;
+//	wifi_softap_get_config(&apconf);
+//	if (strstarts((char *) apconf.ssid, "AI-THINKER")) {
+//		warn("Un-initialized device, performing factory reset.");
+//		apars_handle_OSC_FactoryReset();
+//		return;
+//	}
+
+	// Load and apply stored settings, or defaults if stored settings are invalid
+	persist_load();
+	// Captive portal (DNS redirector)
+	captdnsInit();
+	// Server
+	httpdInit(routes, 80);
+
+	// The terminal screen
+	screen_init();
+
+	// Print the CANCEL character to indicate the module has restarted
+	// Critically important for client application if any kind of screen persistence / content re-use is needed
+	UART_WriteChar(UART0, 24, UART_TIMEOUT_US); // 0x18 - 24 - CAN
+
+	info("Listening on UART0, 115200-8-N-1!");
+}
+
 // ---- unused funcs removed from sdk to save space ---
 
 // вызывается из phy_chip_v6.o
diff --git a/user/wifi_manager.c b/user/wifimgr.c
similarity index 73%
rename from user/wifi_manager.c
rename to user/wifimgr.c
index d19a6dc..04ec363 100644
--- a/user/wifi_manager.c
+++ b/user/wifimgr.c
@@ -2,37 +2,40 @@
 // Created by MightyPork on 2017/07/08.
 //
 
-#include "wifi_manager.h"
+#include "wifimgr.h"
 
-WiFiSettingsBlock wificonf;
+WiFiConfigBlock wificonf;
 
 /**
  * Restore defaults in the WiFi config block.
  * This is to be called if the WiFi config is corrupted on startup,
  * before applying the config.
  */
-void wifimgr_restore_defaults(void)
+void ICACHE_FLASH_ATTR
+wifimgr_restore_defaults(void)
 {
 	u8 mac[6];
 	wifi_get_macaddr(SOFTAP_IF, mac);
 
-	wificonf.opmode = STATIONAP_MODE;
+	wificonf.opmode = SOFTAP_MODE;
 	wificonf.tpw = 20;
 	wificonf.ap_channel = 1;
 	sprintf((char *) wificonf.ap_ssid, "TERM-%02X%02X%02X", mac[3], mac[4], mac[5]);
 	wificonf.ap_password[0] = 0; // PSK2 always if password is not null.
-	wificonf.ap_dhcp_lease_time = 120;
 	wificonf.ap_hidden = false;
 
-	IP4_ADDR(&wificonf.ap_ip.ip, 192, 168, mac[5], 1);
+	IP4_ADDR(&wificonf.ap_ip.ip, 192, 168, 4, 60);
 	IP4_ADDR(&wificonf.ap_ip.netmask, 255, 255, 255, 0);
-	IP4_ADDR(&wificonf.ap_ip.gw, 192, 168, mac[5], 1);
+	wificonf.ap_ip.gw.addr = wificonf.ap_ip.gw.addr;
+
+	IP4_ADDR(&wificonf.ap_dhcp_range.start_ip, 192, 168, 4, 100);
+	IP4_ADDR(&wificonf.ap_dhcp_range.end_ip, 192, 168, 4, 200);
+	wificonf.ap_dhcp_range.enable = 1;
+	wificonf.ap_dhcp_lease_time = 120;
 
 	// --- Client config ---
 	wificonf.sta_ssid[0] = 0;
 	wificonf.sta_password[0] = 0;
-	//sprintf((char *) wificonf.sta_ssid, "Chlivek");
-	//sprintf((char *) wificonf.sta_password, "prase chrochta");
 	strcpy((char *) wificonf.sta_hostname, (char *) wificonf.ap_ssid); // use the same value for sta_hostname as AP name
 	wificonf.sta_dhcp_enable = true;
 
@@ -41,24 +44,8 @@ void wifimgr_restore_defaults(void)
 	IP4_ADDR(&wificonf.sta_ip.gw, 192, 168, 0, 1);
 }
 
-/**
- * Event handler
- */
-void wifimgr_event_cb(System_Event_t *event)
-{
-	switch (event->event) {
-//		case EVENT_STAMODE_CONNECTED:
-//		EVENT_STAMODE_DISCONNECTED,
-//		EVENT_STAMODE_AUTHMODE_CHANGE,
-//		EVENT_STAMODE_GOT_IP,
-//		EVENT_STAMODE_DHCP_TIMEOUT,
-//		EVENT_SOFTAPMODE_STACONNECTED,
-//		EVENT_SOFTAPMODE_STADISCONNECTED,
-//		EVENT_SOFTAPMODE_PROBEREQRECVED,
-	}
-}
-
-static void configure_station(void)
+static void ICACHE_FLASH_ATTR
+configure_station(void)
 {
 	info("[WiFi] Configuring Station mode...");
 	struct station_config conf;
@@ -97,7 +84,8 @@ static void configure_station(void)
 	wifi_station_connect();
 }
 
-static void configure_ap(void)
+static void ICACHE_FLASH_ATTR
+configure_ap(void)
 {
 	bool suc;
 
@@ -108,7 +96,7 @@ static void configure_ap(void)
 	strcpy((char *) conf.ssid, (char *) wificonf.ap_ssid);
 	strcpy((char *) conf.password, (char *) wificonf.ap_password);
 	conf.authmode = (wificonf.ap_password[0] == 0 ? AUTH_OPEN : AUTH_WPA2_PSK);
-	conf.ssid_len = strlen((char *) conf.ssid);
+	conf.ssid_len = (uint8_t) strlen((char *) conf.ssid);
 	conf.ssid_hidden = wificonf.ap_hidden;
 	conf.max_connection = 4; // default 4 (max possible)
 	conf.beacon_interval = 100; // default 100 ms
@@ -137,19 +125,11 @@ static void configure_ap(void)
 	}
 
 	info("[WiFi] Configuring SoftAP DHCP server...");
-	struct dhcps_lease dhcp_lease;
-	struct ip_addr ip;
-	ip.addr = wificonf.ap_ip.ip.addr;
-	ip.addr = (ip.addr & 0x00FFFFFFUL) | ((((ip.addr >> 24) & 0xFF) + 99UL) << 24);
-	dhcp_lease.start_ip.addr = ip.addr;
-	ip.addr = (ip.addr & 0x00FFFFFFUL) | ((((ip.addr >> 24) & 0xFF) + 100UL) << 24);
-	dhcp_lease.end_ip.addr = ip.addr;
-
-	dbg("[WiFi] DHCP.start = "IPSTR, GOOD_IP2STR(dhcp_lease.start_ip.addr));
-	dbg("[WiFi] DHCP.end   = "IPSTR, GOOD_IP2STR(dhcp_lease.end_ip.addr));
+	dbg("[WiFi] DHCP.start = "IPSTR, GOOD_IP2STR(wificonf.ap_dhcp_range.start_ip.addr));
+	dbg("[WiFi] DHCP.end   = "IPSTR, GOOD_IP2STR(wificonf.ap_dhcp_range.end_ip.addr));
 	dbg("[WiFi] DHCP.lease = %d minutes", wificonf.ap_dhcp_lease_time);
 
-	if (!wifi_softap_set_dhcps_lease(&dhcp_lease)) {
+	if (!wifi_softap_set_dhcps_lease(&wificonf.ap_dhcp_range)) {
 		error("[WiFi] DHCP address range set fail!");
 		return;
 	}
@@ -172,13 +152,12 @@ static void configure_ap(void)
 /**
  * Register the WiFi event listener, cycle WiFi, apply settings
  */
-void wifimgr_apply_settings(void)
+void ICACHE_FLASH_ATTR
+wifimgr_apply_settings(void)
 {
-	info("[WiFi] Initializing WiFi manager...");
-//	wifi_set_event_handler_cb(wifimgr_event_cb);
+	info("[WiFi] Initializing...");
 
 	// Force wifi cycle
-	dbg("[WiFi] WiFi reset to apply new settings");
 	wifi_set_opmode(NULL_MODE);
 	wifi_set_opmode(wificonf.opmode);
 
@@ -191,4 +170,6 @@ void wifimgr_apply_settings(void)
 	if (wificonf.opmode == STATIONAP_MODE || wificonf.opmode == SOFTAP_MODE) {
 		configure_ap();
 	}
+
+	info("[WiFi] WiFi settings applied.");
 }
diff --git a/user/wifi_manager.h b/user/wifimgr.h
similarity index 70%
rename from user/wifi_manager.h
rename to user/wifimgr.h
index daf09e3..2bb7f11 100644
--- a/user/wifi_manager.h
+++ b/user/wifimgr.h
@@ -17,28 +17,29 @@
  * This block can be used eg. for WiFi config backup.
  */
 typedef struct {
-	WIFI_MODE opmode : 32;
-	u8 sta_hostname[32];
-	u32 tpw;
+	WIFI_MODE opmode : 8;
+	u8 tpw;
 
 	// --- AP config ---
-	u32 ap_channel; // 32 for alignment, needs 8
+	u8 ap_channel;
 	u8 ap_ssid[32];
 	u8 ap_password[32];
-	u32 ap_hidden;
-	u32 ap_dhcp_lease_time; // in minutes
+	bool ap_hidden;
+	u16 ap_dhcp_lease_time; // in minutes
+	struct dhcps_lease ap_dhcp_range;
 
 	struct ip_info ap_ip;
 
 	// --- Client config ---
 	u8 sta_ssid[32];
 	u8 sta_password[64];
-	u32 sta_dhcp_enable;
+	u8 sta_hostname[32]; // hostname set via the API. This does not seem to have much effect.
+	bool sta_dhcp_enable;
 
 	struct ip_info sta_ip;
-} WiFiSettingsBlock;
+} WiFiConfigBlock;
 
-extern WiFiSettingsBlock wificonf;
+extern WiFiConfigBlock wificonf;
 
 void wifimgr_restore_defaults(void);