diff --git a/FlashProgrammer/WindowsFormsApp1/Form1.Designer.cs b/FlashProgrammer/WindowsFormsApp1/Form1.Designer.cs
index 04f7475..d57b004 100644
--- a/FlashProgrammer/WindowsFormsApp1/Form1.Designer.cs
+++ b/FlashProgrammer/WindowsFormsApp1/Form1.Designer.cs
@@ -166,7 +166,7 @@ private void InitializeComponent()
             this.txtMessages.Multiline = true;
             this.txtMessages.Name = "txtMessages";
             this.txtMessages.ScrollBars = System.Windows.Forms.ScrollBars.Vertical;
-            this.txtMessages.Size = new System.Drawing.Size(681, 85);
+            this.txtMessages.Size = new System.Drawing.Size(681, 306);
             this.txtMessages.TabIndex = 11;
             // 
             // label3
@@ -247,7 +247,7 @@ private void InitializeComponent()
             // 
             this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
-            this.ClientSize = new System.Drawing.Size(715, 546);
+            this.ClientSize = new System.Drawing.Size(715, 770);
             this.Controls.Add(this.button1);
             this.Controls.Add(this.btnClearLog);
             this.Controls.Add(this.btnClearData);
diff --git a/FlashProgrammer/WindowsFormsApp1/Form1.cs b/FlashProgrammer/WindowsFormsApp1/Form1.cs
index fe94b9c..e448d57 100644
--- a/FlashProgrammer/WindowsFormsApp1/Form1.cs
+++ b/FlashProgrammer/WindowsFormsApp1/Form1.cs
@@ -32,7 +32,7 @@ public Form1()
         private void Form1_Load(object sender, EventArgs e)
         {
             //Find last com port and list it in the control.
-
+            _continue = false;
         }
 
         private void AddToMessageLog(string textToAdd)
@@ -87,6 +87,8 @@ private void Serial_DataReceived(object sender, SerialDataReceivedEventArgs e)
             //try
             //{ 
             string data = serial.ReadLine();        //This line is problematic and maybe should be serial.ReadBytes???
+            if (data.StartsWith("OK"))
+                _continue = true;
             if (data.StartsWith("0x"))
                 this.BeginInvoke(new SetTextDeleg(SerialIn_DataReceived), new object[] { data });
             else
@@ -171,7 +173,7 @@ private void btnWrite_Click(object sender, EventArgs e)
         string WriteFileToFlash(string filename)
         {
             string result = "FAILED!";
-
+            
             //Open the file and read into a byte array
             byte[] dataArray = File.ReadAllBytes(filename);
 
@@ -182,32 +184,37 @@ string WriteFileToFlash(string filename)
             txtMessages.Text += "Writing Flash starting at address 0x0000. Please Wait...";
             int addressCounter = 0;
 
-            //send <X,0,0> then <Z,x,0>   where x is 256 or the number of bytes to write, lastly send <Y> and then the full amount of bytes in sequence  
+            //send <X,0,0> then <Z,x,y>   where x is 256 or the number of bytes to write, lastly send <Y> and then the full amount of bytes in sequence  
             //- Arduino side seems to work just need this side to
             int totalSize = dataArray.Length;
 
             serial.WriteLine("<X," + txtStartAddress.Text + ",0>");
-            serial.WriteLine("<Z," + totalSize.ToString() + ",0>");
+            serial.WriteLine("<Z," + "50," + totalSize.ToString() + ">");
             serial.Write("<Y>");
 
             int offset = 0;
-            int block = 256;
+            int block = 50;
             if (block > totalSize)
                 block = totalSize;
             
             //This part needs checking before allowing a write to Flash!!!!!!!
             while(offset < totalSize)
-            {                
+            {
+                _continue = false;
+                if ((offset + block) > totalSize)
+                    block = totalSize - offset;
                 serial.Write(dataArray, offset, block);
                 if (offset + block > totalSize)
                     offset = totalSize - (offset + block);
                 else
                     offset += block;
-                Application.DoEvents();
+                
+                while(_continue == false)
+                    Application.DoEvents();
             }
             //Read the bytes back and compare, using a dump command, ignore and don't read data past where it was written...
 
-            return "Success: Wrote " + (addressCounter + 1).ToString() + " bytes to Flash." + Environment.NewLine;
+            return "Success: Wrote " + totalSize.ToString() + " bytes to Flash." + Environment.NewLine;
         }
 
         private void btnErase_Click(object sender, EventArgs e)
diff --git a/FlashProgrammer/WindowsFormsApp1/bin/Debug/WindowsFormsApp1.exe b/FlashProgrammer/WindowsFormsApp1/bin/Debug/WindowsFormsApp1.exe
index aec491f..c1f6379 100644
Binary files a/FlashProgrammer/WindowsFormsApp1/bin/Debug/WindowsFormsApp1.exe and b/FlashProgrammer/WindowsFormsApp1/bin/Debug/WindowsFormsApp1.exe differ
diff --git a/FlashProgrammer/WindowsFormsApp1/bin/Debug/WindowsFormsApp1.pdb b/FlashProgrammer/WindowsFormsApp1/bin/Debug/WindowsFormsApp1.pdb
index 7570f54..dd9b2df 100644
Binary files a/FlashProgrammer/WindowsFormsApp1/bin/Debug/WindowsFormsApp1.pdb and b/FlashProgrammer/WindowsFormsApp1/bin/Debug/WindowsFormsApp1.pdb differ
diff --git a/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.csproj.GenerateResource.cache b/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.csproj.GenerateResource.cache
index d647e13..cd7bcc5 100644
Binary files a/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.csproj.GenerateResource.cache and b/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.csproj.GenerateResource.cache differ
diff --git a/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.exe b/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.exe
index aec491f..c1f6379 100644
Binary files a/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.exe and b/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.exe differ
diff --git a/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.pdb b/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.pdb
index 7570f54..dd9b2df 100644
Binary files a/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.pdb and b/FlashProgrammer/WindowsFormsApp1/obj/Debug/WindowsFormsApp1.pdb differ