diff --git a/Core/Inc/hal_interface.h b/Core/Inc/hal_interface.h
index bcddd2f..54e5d02 100644
--- a/Core/Inc/hal_interface.h
+++ b/Core/Inc/hal_interface.h
@@ -27,9 +27,7 @@
 #include "stm32f1xx_ll_utils.h"
 #include "stm32f1xx_ll_pwr.h"
 #include "stm32f1xx_ll_dma.h"
-#include "stm32f1xx_ll_rtc.h"
 #include "stm32f1xx_ll_gpio.h"
-#include "stm32f1xx_ll_tim.h"
 
 
 #ifndef HAL_INTERFACE_H_
diff --git a/Core/Inc/regs.h b/Core/Inc/regs.h
index b400fd3..efa6b0f 100644
--- a/Core/Inc/regs.h
+++ b/Core/Inc/regs.h
@@ -23,27 +23,38 @@ enum reg_id {
 	REG_ID_RST_PICO = 0x0E, // Pico reset
 	REG_ID_SHTDW = 0x0F, // self-shutdown
 	REG_ID_INT_CFG = 0x10, // IRQ config
+	REG_ID_RTC_CFG = 0x11, // RTC general config
+	REG_ID_RTC_DATE = 0x12, // RTC date
+	REG_ID_RTC_TIME = 0x13, // RTC time
+	REG_ID_RTC_ALARM_DATE = 0x14, // RTC alarm date
+	REG_ID_RTC_ALARM_TIME = 0x15, // RTC alarm time
 #else
-	REG_ID_CFG = 0x02,			//!< config
-	REG_ID_INT_CFG = 0x03,		//!< IRQ config
-	REG_ID_INT = 0x04,			//!< interrupt status
-	REG_ID_BKL = 0x05,			//!< backlight steps (0-9)
-	REG_ID_BK2 = 0x06,			//!< keyboard backlight (0-9)
-	REG_ID_DEB = 0x07,			//!< debounce cfg (time in ms)
-	REG_ID_FRQ = 0x08,			//!< poll freq cfg (time in ms)
+	REG_ID_CFG = 0x02,				//!< config
+	REG_ID_INT_CFG = 0x03,			//!< IRQ config
+	REG_ID_INT = 0x04,				//!< interrupt status
+	REG_ID_BKL = 0x05,				//!< backlight steps (0-9)
+	REG_ID_BK2 = 0x06,				//!< keyboard backlight (0-9)
+	REG_ID_DEB = 0x07,				//!< debounce cfg (time in ms)
+	REG_ID_FRQ = 0x08,				//!< poll freq cfg (time in ms)
 
-	REG_ID_KEY = 0x10,			//!< key status
-	REG_ID_FIF = 0x11,			//!< fifo
-	REG_ID_C64_MTX = 0x12,		//!< read c64 matrix
-	REG_ID_C64_JS = 0x13,		//!< joystick io bits
+	REG_ID_RTC_CFG = 0x0A,			//!< RTC general config
+	REG_ID_RTC_DATE = 0x0B,			//!< RTC date
+	REG_ID_RTC_TIME = 0x0C,			//!< RTC time
+	REG_ID_RTC_ALARM_DATE = 0x0D,	//!< RTC alarm date
+	REG_ID_RTC_ALARM_TIME = 0x0E,	//!< RTC alarm time
 
-	REG_ID_RST = 0x20,			//!< STM32 full reset
-	REG_ID_RST_PICO = 0x21,		//!< Pico reset
-	REG_ID_SHTDW = 0x22,		//!< self-shutdown
+	REG_ID_KEY = 0x10,				//!< key status
+	REG_ID_FIF = 0x11,				//!< fifo
+	REG_ID_C64_MTX = 0x12,			//!< read c64 matrix
+	REG_ID_C64_JS = 0x13,			//!< joystick io bits
 
-	REG_ID_BAT = 0x30,			//!< battery
+	REG_ID_RST = 0x20,				//!< STM32 full reset
+	REG_ID_RST_PICO = 0x21,			//!< Pico reset
+	REG_ID_SHTDW = 0x22,			//!< self-shutdown
+
+	REG_ID_BAT = 0x30,				//!< battery
 #endif
-	REG_ID_LAST,
+	REG_ID_LAST
 };
 
 #define CFG_OVERFLOW_ON		(1 << 0) //When a FIFO overflow happens, should the new entry still be pushed, overwriting the oldest one. If 0 then new entry is lost.
diff --git a/Core/Inc/stm32f1xx_hal_conf.h b/Core/Inc/stm32f1xx_hal_conf.h
index fe77540..f7b0a5d 100644
--- a/Core/Inc/stm32f1xx_hal_conf.h
+++ b/Core/Inc/stm32f1xx_hal_conf.h
@@ -57,7 +57,7 @@
 /*#define HAL_HCD_MODULE_ENABLED   */
 /*#define HAL_PWR_MODULE_ENABLED   */
 /*#define HAL_RCC_MODULE_ENABLED   */
-/*#define HAL_RTC_MODULE_ENABLED   */
+#define HAL_RTC_MODULE_ENABLED
 /*#define HAL_SD_MODULE_ENABLED   */
 /*#define HAL_MMC_MODULE_ENABLED   */
 /*#define HAL_SDRAM_MODULE_ENABLED   */
diff --git a/Core/Inc/stm32f1xx_it.h b/Core/Inc/stm32f1xx_it.h
index 254de69..5c58f9f 100644
--- a/Core/Inc/stm32f1xx_it.h
+++ b/Core/Inc/stm32f1xx_it.h
@@ -65,6 +65,7 @@ void USART1_IRQHandler(void);
 #ifdef UART_PICO_INTERFACE
 void USART3_IRQHandler(void);
 #endif
+void RTC_Alarm_IRQHandler(void);
 /* USER CODE BEGIN EFP */
 
 /* USER CODE END EFP */
diff --git a/Core/Src/hal_interface.c b/Core/Src/hal_interface.c
index 0801d6f..2e4d66a 100644
--- a/Core/Src/hal_interface.c
+++ b/Core/Src/hal_interface.c
@@ -23,6 +23,8 @@
 I2C_HandleTypeDef hi2c1;
 I2C_HandleTypeDef hi2c2;
 
+RTC_HandleTypeDef hrtc;
+
 TIM_HandleTypeDef htim1;
 TIM_HandleTypeDef htim2;
 TIM_HandleTypeDef htim3;
@@ -140,28 +142,33 @@ static void MX_IWDG_Init(void) {
   * @retval None
   */
 static void MX_RTC_Init(void) {
-	LL_RTC_InitTypeDef RTC_InitStruct = {0};
-	LL_RTC_TimeTypeDef RTC_TimeStruct = {0};
-
-	LL_PWR_EnableBkUpAccess();
-	/* Enable BKP CLK enable for backup registers */
-	LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_BKP);
-	/* Peripheral clock enable */
-	LL_RCC_EnableRTC();
+	RTC_TimeTypeDef sTime = {0};
+	RTC_DateTypeDef DateToUpdate = {0};
 
+	/** Initialize RTC Only
+	*/
+	hrtc.Instance = RTC;
+	hrtc.Init.AsynchPrediv = RTC_AUTO_1_SECOND;
+	hrtc.Init.OutPut = RTC_OUTPUTSOURCE_ALARM;
+	if (HAL_RTC_Init(&hrtc) != HAL_OK)
+		Error_Handler();
 
 	/** Initialize RTC and set the Time and Date
 	*/
-	RTC_InitStruct.AsynchPrescaler = 0xFFFFFFFFU;
-	LL_RTC_Init(RTC, &RTC_InitStruct);
-	LL_RTC_SetAsynchPrescaler(RTC, 0xFFFFFFFFU);
+	sTime.Hours = 0x0;
+	sTime.Minutes = 0x0;
+	sTime.Seconds = 0x0;
 
-	/** Initialize RTC and set the Time and Date
-	*/
-	RTC_TimeStruct.Hours = 0;
-	RTC_TimeStruct.Minutes = 0;
-	RTC_TimeStruct.Seconds = 0;
-	LL_RTC_TIME_Init(RTC, LL_RTC_FORMAT_BCD, &RTC_TimeStruct);
+	if (HAL_RTC_SetTime(&hrtc, &sTime, RTC_FORMAT_BCD) != HAL_OK)
+		Error_Handler();
+
+	DateToUpdate.WeekDay = RTC_WEEKDAY_MONDAY;
+	DateToUpdate.Month = RTC_MONTH_JANUARY;
+	DateToUpdate.Date = 0x1;
+	DateToUpdate.Year = 0x0;
+
+	if (HAL_RTC_SetDate(&hrtc, &DateToUpdate, RTC_FORMAT_BCD) != HAL_OK)
+		Error_Handler();
 }
 
 /**
@@ -529,6 +536,41 @@ void HAL_I2C_MspDeInit(I2C_HandleTypeDef* hi2c) {
 	}
 }
 
+/**
+  * @brief RTC MSP Initialization
+  * This function configures the hardware resources used in this example
+  * @param hrtc: RTC handle pointer
+  * @retval None
+  */
+void HAL_RTC_MspInit(RTC_HandleTypeDef* hrtc) {
+	if (hrtc->Instance == RTC) {
+		HAL_PWR_EnableBkUpAccess();
+		/* Enable BKP CLK enable for backup registers */
+		__HAL_RCC_BKP_CLK_ENABLE();
+		/* Peripheral clock enable */
+		__HAL_RCC_RTC_ENABLE();
+		/* RTC interrupt Init */
+		HAL_NVIC_SetPriority(RTC_Alarm_IRQn, 0, 0);
+		HAL_NVIC_EnableIRQ(RTC_Alarm_IRQn);
+	}
+}
+
+/**
+  * @brief RTC MSP De-Initialization
+  * This function freeze the hardware resources used in this example
+  * @param hrtc: RTC handle pointer
+  * @retval None
+  */
+void HAL_RTC_MspDeInit(RTC_HandleTypeDef* hrtc) {
+	if (hrtc->Instance == RTC) {
+		/* Peripheral clock disable */
+		__HAL_RCC_RTC_DISABLE();
+
+		/* RTC interrupt DeInit */
+		HAL_NVIC_DisableIRQ(RTC_Alarm_IRQn);
+	}
+}
+
 /**
   * @brief TIM_Base MSP Initialization
   * This function configures the hardware resources used in this example
diff --git a/Core/Src/main.c b/Core/Src/main.c
index 7b06ed5..74945a5 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -54,6 +54,8 @@ enum i2cs_state {
 extern I2C_HandleTypeDef hi2c1;
 extern I2C_HandleTypeDef hi2c2;
 
+extern RTC_HandleTypeDef hrtc;
+
 extern TIM_HandleTypeDef htim1;
 extern TIM_HandleTypeDef htim2;
 extern TIM_HandleTypeDef htim3;
@@ -93,6 +95,10 @@ static void sync_bat(void);
 static void printPMU(void);
 #endif
 static void check_pmu_int(void);
+static void i2cs_fill_buffer_RTC_date(uint8_t* date_buff);
+static void i2cs_fill_buffer_RTC_time(uint8_t* time_buff);
+static void i2cs_RTC_date_from_buffer(uint8_t* date_buff);
+static void i2cs_RTC_time_from_buffer(uint8_t* time_buff);
 
 extern void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) {
 	if (htim == &htim2) {
@@ -166,6 +172,16 @@ extern void HAL_I2C_AddrCallback(I2C_HandleTypeDef *hi2c, uint8_t TransferDirect
 					i2cs_w_buff[1] = reg_get_value(REG_ID_TYP);
 				} else if (reg == REG_ID_BAT) {
 					i2cs_w_buff[1] = reg_get_value(REG_ID_BAT);
+				} else if (reg == REG_ID_RTC_DATE) {
+					if (is_write)
+						i2cs_RTC_date_from_buffer(&i2cs_r_buff[1]);
+					i2cs_fill_buffer_RTC_date(&i2cs_w_buff[1]);
+					i2cs_w_len = 5;
+				} else if (reg == REG_ID_RTC_TIME) {
+					if (is_write)
+						i2cs_RTC_time_from_buffer(&i2cs_r_buff[1]);
+					i2cs_fill_buffer_RTC_time(&i2cs_w_buff[1]);
+					i2cs_w_len = 4;
 				} else if (reg == REG_ID_KEY) {
 					i2cs_w_buff[0] = fifo_count();
 					i2cs_w_buff[0] |= keyboard_get_numlock() ? KEY_NUMLOCK : 0x00;
@@ -229,6 +245,10 @@ extern void HAL_I2C_SlaveRxCpltCallback(I2C_HandleTypeDef *hi2c) {
 			} else if (reg == REG_ID_DEB) {
 				if (is_write)
 					bytes_needed = 2;
+			} else if (reg == REG_ID_RTC_TIME ||
+				reg == REG_ID_RTC_DATE) {
+				if (is_write)
+					bytes_needed = 4;
 			}
 
 			if (bytes_needed > 0)
@@ -808,3 +828,45 @@ __STATIC_INLINE void check_pmu_int(void) {
 		AXP2101_clearIrqStatus();
 	}
 }
+
+__STATIC_INLINE void i2cs_fill_buffer_RTC_date(uint8_t* date_buff) {
+	RTC_DateTypeDef data_s = {0};
+
+	HAL_RTC_GetDate(&hrtc, &data_s, RTC_FORMAT_BCD);
+
+	date_buff[0] = data_s.Year;
+	date_buff[1] = data_s.Month;
+	date_buff[2] = data_s.Date;
+	date_buff[3] = data_s.WeekDay;
+}
+
+__STATIC_INLINE void i2cs_fill_buffer_RTC_time(uint8_t* time_buff) {
+	RTC_TimeTypeDef time_s = {0};
+
+	HAL_RTC_GetTime(&hrtc, &time_s, RTC_FORMAT_BCD);
+
+	time_buff[0] = time_s.Hours;
+	time_buff[1] = time_s.Minutes;
+	time_buff[2] = time_s.Seconds;
+}
+
+__STATIC_INLINE void i2cs_RTC_date_from_buffer(uint8_t* date_buff) {
+	RTC_DateTypeDef data_s = {0};
+
+	data_s.Year = date_buff[0] <= 99? date_buff[0] : 99;
+	data_s.Month = (date_buff[1] > 0 && date_buff[1] <= 12)? date_buff[1] : 12;
+	data_s.Date = (date_buff[2] > 0 && date_buff[2] <= 99)? date_buff[2] : 99;
+	//data_s.WeekDay - this element is automatically recomputed
+
+	HAL_RTC_SetDate(&hrtc, &data_s, RTC_FORMAT_BIN);
+}
+
+__STATIC_INLINE void i2cs_RTC_time_from_buffer(uint8_t* time_buff) {
+	RTC_TimeTypeDef time_s = {0};
+
+	time_s.Hours = time_buff[0] <= 23 ? time_buff[0] : 23;
+	time_s.Minutes = time_buff[1] <= 59 ? time_buff[1] : 59;
+	time_s.Seconds = time_buff[2] <= 59 ? time_buff[2] : 59;
+
+	HAL_RTC_SetTime(&hrtc, &time_s, RTC_FORMAT_BIN);
+}
diff --git a/Core/Src/stm32f1xx_it.c b/Core/Src/stm32f1xx_it.c
index 276b493..8902de9 100644
--- a/Core/Src/stm32f1xx_it.c
+++ b/Core/Src/stm32f1xx_it.c
@@ -16,6 +16,7 @@
 
 
 extern I2C_HandleTypeDef hi2c1;
+extern RTC_HandleTypeDef hrtc;
 extern TIM_HandleTypeDef htim2;
 #ifdef DEBUG
 extern UART_HandleTypeDef huart1;
@@ -146,3 +147,10 @@ void USART3_IRQHandler(void) {
 	HAL_UART_IRQHandler(&huart3);
 }
 #endif
+
+/**
+  * @brief This function handles RTC alarm interrupt through EXTI line 17.
+  */
+void RTC_Alarm_IRQHandler(void) {
+	HAL_RTC_AlarmIRQHandler(&hrtc);
+}
diff --git a/CubeMX/picocalc_BIOS_jcs.ioc b/CubeMX/picocalc_BIOS_jcs.ioc
index c7099cd..d646c9b 100644
--- a/CubeMX/picocalc_BIOS_jcs.ioc
+++ b/CubeMX/picocalc_BIOS_jcs.ioc
@@ -76,17 +76,16 @@ Mcu.Pin47=VP_IWDG_VS_IWDG
 Mcu.Pin48=VP_RTC_VS_RTC_Activate
 Mcu.Pin49=VP_RTC_VS_RTC_Calendar
 Mcu.Pin5=PC0
-Mcu.Pin50=VP_RTC_No_RTC_Output
-Mcu.Pin51=VP_SYS_VS_ND
-Mcu.Pin52=VP_SYS_VS_Systick
-Mcu.Pin53=VP_TIM1_VS_ClockSourceINT
-Mcu.Pin54=VP_TIM2_VS_ClockSourceINT
-Mcu.Pin55=VP_TIM3_VS_ClockSourceINT
+Mcu.Pin50=VP_SYS_VS_ND
+Mcu.Pin51=VP_SYS_VS_Systick
+Mcu.Pin52=VP_TIM1_VS_ClockSourceINT
+Mcu.Pin53=VP_TIM2_VS_ClockSourceINT
+Mcu.Pin54=VP_TIM3_VS_ClockSourceINT
 Mcu.Pin6=PC1
 Mcu.Pin7=PC2
 Mcu.Pin8=PC3
 Mcu.Pin9=PA0-WKUP
-Mcu.PinsNb=56
+Mcu.PinsNb=55
 Mcu.ThirdPartyNb=0
 Mcu.UserConstants=
 Mcu.UserName=STM32F103R8Tx
@@ -103,6 +102,7 @@ NVIC.MemoryManagement_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false
 NVIC.NonMaskableInt_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false
 NVIC.PendSV_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false
 NVIC.PriorityGroup=NVIC_PRIORITYGROUP_4
+NVIC.RTC_Alarm_IRQn=true\:0\:0\:false\:false\:true\:true\:true\:true
 NVIC.SVCall_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false
 NVIC.SysTick_IRQn=true\:1\:0\:true\:false\:true\:false\:true\:false
 NVIC.TIM2_IRQn=true\:1\:0\:true\:false\:true\:true\:true\:true
@@ -413,12 +413,12 @@ ProjectManager.ProjectName=picocalc_BIOS_jcs
 ProjectManager.ProjectStructure=
 ProjectManager.RegisterCallBack=
 ProjectManager.StackSize=0x400
-ProjectManager.TargetToolchain=STM32CubeIDE
+ProjectManager.TargetToolchain=Makefile
 ProjectManager.ToolChainLocation=
 ProjectManager.UAScriptAfterPath=
 ProjectManager.UAScriptBeforePath=
-ProjectManager.UnderRoot=true
-ProjectManager.functionlistsort=1-SystemClock_Config-RCC-false-LL-false,2-MX_GPIO_Init-GPIO-false-LL-true,3-MX_I2C1_Init-I2C1-false-HAL-true,4-MX_I2C2_Init-I2C2-false-HAL-true,5-MX_RTC_Init-RTC-false-LL-true,6-MX_USART1_UART_Init-USART1-false-HAL-true,7-MX_USART3_UART_Init-USART3-false-HAL-true,8-MX_IWDG_Init-IWDG-false-LL-true,9-MX_TIM1_Init-TIM1-false-HAL-true,10-MX_TIM3_Init-TIM3-false-HAL-true,11-MX_TIM2_Init-TIM2-false-HAL-true
+ProjectManager.UnderRoot=false
+ProjectManager.functionlistsort=1-SystemClock_Config-RCC-false-LL-false,2-MX_GPIO_Init-GPIO-false-LL-true,3-MX_I2C1_Init-I2C1-false-HAL-true,4-MX_I2C2_Init-I2C2-false-HAL-true,5-MX_RTC_Init-RTC-false-HAL-true,6-MX_USART1_UART_Init-USART1-false-HAL-true,7-MX_USART3_UART_Init-USART3-false-HAL-true,8-MX_IWDG_Init-IWDG-false-LL-true,9-MX_TIM1_Init-TIM1-false-HAL-true,10-MX_TIM3_Init-TIM3-false-HAL-true,11-MX_TIM2_Init-TIM2-false-HAL-true
 RCC.ADCFreqValue=2000000
 RCC.AHBCLKDivider=RCC_SYSCLK_DIV2
 RCC.AHBFreq_Value=4000000
@@ -474,8 +474,6 @@ USART3.IPParameters=VirtualMode
 USART3.VirtualMode=VM_ASYNC
 VP_IWDG_VS_IWDG.Mode=IWDG_Activate
 VP_IWDG_VS_IWDG.Signal=IWDG_VS_IWDG
-VP_RTC_No_RTC_Output.Mode=RTC_OUT_NO
-VP_RTC_No_RTC_Output.Signal=RTC_No_RTC_Output
 VP_RTC_VS_RTC_Activate.Mode=RTC_Enabled
 VP_RTC_VS_RTC_Activate.Signal=RTC_VS_RTC_Activate
 VP_RTC_VS_RTC_Calendar.Mode=RTC_Calendar