diff --git a/Include/MyIncludes/TDI_Calculator.mqh b/Include/MyIncludes/TDI_Calculator.mqh
index 0b9907e..e72a563 100644
--- a/Include/MyIncludes/TDI_Calculator.mqh
+++ b/Include/MyIncludes/TDI_Calculator.mqh
@@ -1,6 +1,6 @@
 //+------------------------------------------------------------------+
 //|                                               TDI_Calculator.mqh |
-//|        Calculation engine for Standard and Heikin Ashi TDI.      |
+//|      VERSION 2.01: Fixed override signature mismatch.            |
 //|                                        Copyright 2025, xxxxxxxx  |
 //+------------------------------------------------------------------+
 #property copyright "Copyright 2025, xxxxxxxx"
@@ -8,31 +8,32 @@
 #include <MyIncludes\HeikinAshi_Tools.mqh>
 
 //+==================================================================+
-//|                                                                  |
 //|             CLASS 1: CTDICalculator (Base Class)                 |
-//|                                                                  |
 //+==================================================================+
 class CTDICalculator
   {
 protected:
    int               m_rsi_period, m_price_period, m_signal_period, m_base_period;
    double            m_std_dev;
-   double            m_price[];
 
-   virtual bool      PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]);
+   //--- Persistent Buffers
+   double            m_price[];
+   double            m_rsi_buffer[];
+
+   virtual bool      PreparePriceSeries(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]);
 
 public:
                      CTDICalculator(void) {};
    virtual          ~CTDICalculator(void) {};
 
    bool              Init(int rsi_p, int price_p, int signal_p, int base_p, double dev);
-   void              Calculate(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[],
+   void              Calculate(int rates_total, int prev_calculated, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[],
                                double &price_line_out[], double &signal_line_out[], double &base_line_out[],
                                double &upper_band_out[], double &lower_band_out[]);
   };
 
 //+------------------------------------------------------------------+
-//| CTDICalculator: Initialization                                   |
+//| Init                                                             |
 //+------------------------------------------------------------------+
 bool CTDICalculator::Init(int rsi_p, int price_p, int signal_p, int base_p, double dev)
   {
@@ -45,47 +46,64 @@ bool CTDICalculator::Init(int rsi_p, int price_p, int signal_p, int base_p, doub
   }
 
 //+------------------------------------------------------------------+
-//| CTDICalculator: Main Calculation Method (Definition-True)        |
+//| Main Calculation (Optimized)                                     |
 //+------------------------------------------------------------------+
-void CTDICalculator::Calculate(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[],
+void CTDICalculator::Calculate(int rates_total, int prev_calculated, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[],
                                double &price_line_out[], double &signal_line_out[], double &base_line_out[],
                                double &upper_band_out[], double &lower_band_out[])
   {
    if(rates_total <= m_rsi_period + m_base_period)
       return;
-   if(!PreparePriceSeries(rates_total, price_type, open, high, low, close))
+
+   int start_index;
+   if(prev_calculated == 0)
+      start_index = 0;
+   else
+      start_index = prev_calculated - 1;
+
+   if(ArraySize(m_price) != rates_total)
+     {
+      ArrayResize(m_price, rates_total);
+      ArrayResize(m_rsi_buffer, rates_total);
+     }
+
+   if(!PreparePriceSeries(rates_total, start_index, price_type, open, high, low, close))
       return;
 
-   double rsi_buffer[];
-   ArrayResize(rsi_buffer, rates_total);
-
-//--- STEP 1: Calculate RSI (Wilder's smoothing)
+// RSI Loop
    double sum_pos = 0, sum_neg = 0;
    for(int i = 1; i < rates_total; i++)
      {
       double diff = m_price[i] - m_price[i-1];
       sum_pos = (sum_pos * (m_rsi_period - 1) + (diff > 0 ? diff : 0)) / m_rsi_period;
       sum_neg = (sum_neg * (m_rsi_period - 1) + (diff < 0 ? -diff : 0)) / m_rsi_period;
+
       if(i >= m_rsi_period)
         {
          if(sum_neg > 0)
-            rsi_buffer[i] = 100.0 - (100.0 / (1.0 + (sum_pos / sum_neg)));
+            m_rsi_buffer[i] = 100.0 - (100.0 / (1.0 + (sum_pos / sum_neg)));
          else
-            rsi_buffer[i] = 100.0;
+            m_rsi_buffer[i] = 100.0;
         }
+      else
+         m_rsi_buffer[i] = 0;
      }
 
-//--- STEP 2: Calculate Price Line (SMA on RSI)
-   for(int i = m_rsi_period + m_price_period - 2; i < rates_total; i++)
+// Price Line
+   int pl_start = m_rsi_period + m_price_period - 2;
+   int loop_start_pl = MathMax(pl_start, start_index);
+   for(int i = loop_start_pl; i < rates_total; i++)
      {
       double sum=0;
       for(int j=0; j<m_price_period; j++)
-         sum+=rsi_buffer[i-j];
+         sum+=m_rsi_buffer[i-j];
       price_line_out[i]=sum/m_price_period;
      }
 
-//--- STEP 3: Calculate Signal Line (SMA on Price Line)
-   for(int i = m_rsi_period + m_price_period + m_signal_period - 3; i < rates_total; i++)
+// Signal Line
+   int sl_start = pl_start + m_signal_period - 1;
+   int loop_start_sl = MathMax(sl_start, start_index);
+   for(int i = loop_start_sl; i < rates_total; i++)
      {
       double sum=0;
       for(int j=0; j<m_signal_period; j++)
@@ -93,8 +111,10 @@ void CTDICalculator::Calculate(int rates_total, ENUM_APPLIED_PRICE price_type, c
       signal_line_out[i]=sum/m_signal_period;
      }
 
-//--- STEP 4: Calculate Base Line (SMA on Price Line)
-   for(int i = m_rsi_period + m_price_period + m_base_period - 3; i < rates_total; i++)
+// Base Line
+   int bl_start = pl_start + m_base_period - 1;
+   int loop_start_bl = MathMax(bl_start, start_index);
+   for(int i = loop_start_bl; i < rates_total; i++)
      {
       double sum=0;
       for(int j=0; j<m_base_period; j++)
@@ -102,21 +122,22 @@ void CTDICalculator::Calculate(int rates_total, ENUM_APPLIED_PRICE price_type, c
       base_line_out[i]=sum/m_base_period;
      }
 
-//--- STEP 5: Calculate Volatility Bands (Bollinger Bands on Base Line, using RSI data for StdDev)
-   int bands_start = m_rsi_period + m_base_period - 2; // BBands on RSI, centered on Base Line
-   for(int i = bands_start; i < rates_total; i++)
+// Bands
+   int bands_start = m_rsi_period + m_base_period - 2;
+   int loop_start_bands = MathMax(bands_start, start_index);
+   for(int i = loop_start_bands; i < rates_total; i++)
      {
-      double std_dev = 0, sum_sq = 0;
-      // The standard deviation for TDI bands is calculated on the RSI, not the base line itself.
-      double base_line_ma_on_rsi = 0;
+      double rsi_ma = 0;
       double sum_rsi = 0;
       for(int j=0; j<m_base_period; j++)
-         sum_rsi += rsi_buffer[i-j];
-      base_line_ma_on_rsi = sum_rsi / m_base_period;
+         sum_rsi += m_rsi_buffer[i-j];
+      rsi_ma = sum_rsi / m_base_period;
 
+      double sum_sq = 0;
       for(int j = 0; j < m_base_period; j++)
-         sum_sq += MathPow(rsi_buffer[i-j] - base_line_ma_on_rsi, 2);
-      std_dev = MathSqrt(sum_sq / m_base_period);
+         sum_sq += MathPow(m_rsi_buffer[i-j] - rsi_ma, 2);
+
+      double std_dev = MathSqrt(sum_sq / m_base_period);
 
       upper_band_out[i] = base_line_out[i] + m_std_dev * std_dev;
       lower_band_out[i] = base_line_out[i] - m_std_dev * std_dev;
@@ -124,99 +145,103 @@ void CTDICalculator::Calculate(int rates_total, ENUM_APPLIED_PRICE price_type, c
   }
 
 //+------------------------------------------------------------------+
-//| CTDICalculator: Prepares the standard source price series.       |
+//| Prepare Price (Standard)                                         |
 //+------------------------------------------------------------------+
-bool CTDICalculator::PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
+bool CTDICalculator::PreparePriceSeries(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
   {
-   ArrayResize(m_price, rates_total);
-   switch(price_type)
+   for(int i = start_index; i < rates_total; i++)
      {
-      case PRICE_CLOSE:
-         ArrayCopy(m_price, close, 0, 0, rates_total);
-         break;
-      case PRICE_OPEN:
-         ArrayCopy(m_price, open, 0, 0, rates_total);
-         break;
-      case PRICE_HIGH:
-         ArrayCopy(m_price, high, 0, 0, rates_total);
-         break;
-      case PRICE_LOW:
-         ArrayCopy(m_price, low, 0, 0, rates_total);
-         break;
-      case PRICE_MEDIAN:
-         for(int i=0; i<rates_total; i++)
+      switch(price_type)
+        {
+         case PRICE_CLOSE:
+            m_price[i] = close[i];
+            break;
+         case PRICE_OPEN:
+            m_price[i] = open[i];
+            break;
+         case PRICE_HIGH:
+            m_price[i] = high[i];
+            break;
+         case PRICE_LOW:
+            m_price[i] = low[i];
+            break;
+         case PRICE_MEDIAN:
             m_price[i] = (high[i]+low[i])/2.0;
-         break;
-      case PRICE_TYPICAL:
-         for(int i=0; i<rates_total; i++)
+            break;
+         case PRICE_TYPICAL:
             m_price[i] = (high[i]+low[i]+close[i])/3.0;
-         break;
-      case PRICE_WEIGHTED:
-         for(int i=0; i<rates_total; i++)
-            m_price[i] = (high[i]+low[i]+close[i]+close[i])/4.0;
-         break;
-      default:
-         return false;
+            break;
+         case PRICE_WEIGHTED:
+            m_price[i] = (high[i]+low[i]+2*close[i])/4.0;
+            break;
+         default:
+            m_price[i] = close[i];
+            break;
+        }
      }
    return true;
   }
 
 //+==================================================================+
-//|                                                                  |
 //|             CLASS 2: CTDICalculator_HA (Heikin Ashi)             |
-//|                                                                  |
 //+==================================================================+
 class CTDICalculator_HA : public CTDICalculator
   {
 private:
    CHeikinAshi_Calculator m_ha_calculator;
+   double            m_ha_open[], m_ha_high[], m_ha_low[], m_ha_close[];
+
 protected:
-   virtual bool      PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]) override;
+   // FIX: Added 'price_type' to match base class signature
+   virtual bool      PreparePriceSeries(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]) override;
   };
 
 //+------------------------------------------------------------------+
-//| CTDICalculator_HA: Prepares the Heikin Ashi source price.        |
+//| Prepare Price (Heikin Ashi)                                      |
 //+------------------------------------------------------------------+
-bool CTDICalculator_HA::PreparePriceSeries(int rates_total, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
+bool CTDICalculator_HA::PreparePriceSeries(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
   {
-   double ha_open[], ha_high[], ha_low[], ha_close[];
-   ArrayResize(ha_open, rates_total);
-   ArrayResize(ha_high, rates_total);
-   ArrayResize(ha_low, rates_total);
-   ArrayResize(ha_close, rates_total);
-   m_ha_calculator.Calculate(rates_total, open, high, low, close, ha_open, ha_high, ha_low, ha_close);
-
-   ArrayResize(m_price, rates_total);
-   switch(price_type)
+   if(ArraySize(m_ha_open) != rates_total)
      {
-      case PRICE_CLOSE:
-         ArrayCopy(m_price, ha_close, 0, 0, rates_total);
-         break;
-      case PRICE_OPEN:
-         ArrayCopy(m_price, ha_open, 0, 0, rates_total);
-         break;
-      case PRICE_HIGH:
-         ArrayCopy(m_price, ha_high, 0, 0, rates_total);
-         break;
-      case PRICE_LOW:
-         ArrayCopy(m_price, ha_low, 0, 0, rates_total);
-         break;
-      case PRICE_MEDIAN:
-         for(int i=0; i<rates_total; i++)
-            m_price[i] = (ha_high[i]+ha_low[i])/2.0;
-         break;
-      case PRICE_TYPICAL:
-         for(int i=0; i<rates_total; i++)
-            m_price[i] = (ha_high[i]+ha_low[i]+ha_close[i])/3.0;
-         break;
-      case PRICE_WEIGHTED:
-         for(int i=0; i<rates_total; i++)
-            m_price[i] = (ha_high[i]+ha_low[i]+ha_close[i]+ha_close[i])/4.0;
-         break;
-      default:
-         return false;
+      ArrayResize(m_ha_open, rates_total);
+      ArrayResize(m_ha_high, rates_total);
+      ArrayResize(m_ha_low, rates_total);
+      ArrayResize(m_ha_close, rates_total);
+     }
+
+   m_ha_calculator.Calculate(rates_total, start_index, open, high, low, close,
+                             m_ha_open, m_ha_high, m_ha_low, m_ha_close);
+
+   for(int i = start_index; i < rates_total; i++)
+     {
+      switch(price_type)
+        {
+         case PRICE_CLOSE:
+            m_price[i] = m_ha_close[i];
+            break;
+         case PRICE_OPEN:
+            m_price[i] = m_ha_open[i];
+            break;
+         case PRICE_HIGH:
+            m_price[i] = m_ha_high[i];
+            break;
+         case PRICE_LOW:
+            m_price[i] = m_ha_low[i];
+            break;
+         case PRICE_MEDIAN:
+            m_price[i] = (m_ha_high[i]+m_ha_low[i])/2.0;
+            break;
+         case PRICE_TYPICAL:
+            m_price[i] = (m_ha_high[i]+m_ha_low[i]+m_ha_close[i])/3.0;
+            break;
+         case PRICE_WEIGHTED:
+            m_price[i] = (m_ha_high[i]+m_ha_low[i]+2*m_ha_close[i])/4.0;
+            break;
+         default:
+            m_price[i] = m_ha_close[i];
+            break;
+        }
      }
    return true;
   }
 //+------------------------------------------------------------------+
-//+------------------------------------------------------------------+