diff --git a/src/pad.cpp b/src/pad.cpp
new file mode 100644
index 0000000..49636e0
--- /dev/null
+++ b/src/pad.cpp
@@ -0,0 +1,452 @@
+/*
+ * This file is a part of TTCalc - a mathematical calculator
+ * and is distributed under the (new) BSD licence.
+ * Author: Tomasz Sowa <t.sowa@slimaczek.pl>
+ */
+
+/* 
+ * Copyright (c) 2006-2009, Tomasz Sowa
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *    
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *    
+ *  * Neither the name Tomasz Sowa nor the names of contributors to this
+ *    project may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <windows.h>
+#include <ttmath/ttmath.h>
+#include "programresources.h"
+#include "resource.h"
+#include "messages.h"
+#include "bigtypes.h"
+
+
+namespace Pad
+{
+HWND edit;
+WNDPROC old_edit_proc;
+std::string parse_string;
+int precision;
+
+int  base_input;
+int  base_output;
+bool always_scientific;
+int  when_scientific;
+int  rounding;
+bool remove_zeroes;
+int  angle_deg_rad_grad;
+char decimal_point;
+Languages::Country country;
+ttmath::Objects * variables;
+ttmath::Objects * functions;
+ttmath::ErrorCode code;
+bool calculated;
+
+std::string res, res2;
+
+#ifndef TTCALC_PORTABLE
+	ttmath::Parser<TTMathBig1> parser1;
+	ttmath::Parser<TTMathBig2> parser2;
+	ttmath::Parser<TTMathBig3> parser3;
+#else
+	ttmath::Parser<TTMathBig1> parser1;
+#endif
+
+
+void PutChars(const char * str)
+{
+	SendMessage(edit, EM_REPLACESEL, true, (LPARAM)str);
+}
+
+
+void PutChars(std::string & str)
+{
+	PutChars(str.c_str());
+}
+
+
+void PutOverflowMsg()
+{
+	PutChars(GetPrgRes()->GetLanguages()->ErrorMessage(country, ttmath::err_overflow));
+	PutChars("\r\n");
+}
+
+
+template<typename ValueType>
+void PutResultFromParser(ttmath::Parser<ValueType> & matparser)
+{
+unsigned int i = 0;
+
+	res.clear();
+	res2.clear();
+
+	for(i=0 ; i<matparser.stack.size() ; ++i)
+	{
+		try
+		{
+			ValueType result = matparser.stack[i].value;
+			
+			if( result.ToString(res2, base_output, always_scientific, when_scientific, rounding, remove_zeroes, decimal_point) )
+				res2 = GetPrgRes()->GetLanguages()->GuiMessage(country, Languages::overflow_during_printing);
+		}
+		catch(...)
+		{
+			res2 = GetPrgRes()->GetLanguages()->ErrorMessage(country, ttmath::err_internal_error);
+		}
+
+		res += res2;
+
+		if( i < matparser.stack.size()-1 )
+			res += "\r\n";
+	}
+
+	res += ' ';
+	PutChars(res);
+}
+
+
+void PutResult()
+{
+	#ifndef TTCALC_PORTABLE
+
+		switch( precision )
+		{
+		case 0:
+			PutResultFromParser(parser1);
+			break;
+
+		case 1:
+			PutResultFromParser(parser2);
+			break;
+
+		default:
+			PutResultFromParser(parser3);
+			break;
+		}
+
+	#else
+
+		PutResultFromParser(parser1);
+
+	#endif
+}
+
+
+
+// line - index of a line -- as you see it on the edit control
+// (if the text is wrapped then the line is larger)
+void GetParseString(const char * buf, int line)
+{
+int i;
+
+	int first_line_char = SendMessage(edit, EM_LINEINDEX, line, 0);
+	// first_line_char takes into consideration \r\n characters
+
+	if( first_line_char < 0 )
+		// something wrong
+		return;
+
+	// looking for the line
+	for(i=0 ; i<first_line_char && buf[i]!=0 ; ++i);
+
+	// looking for the beginning of the line
+	for( ; i>0 && buf[i-1]!=10 ; --i);
+
+	// copying the whole line
+	for( ; buf[i]!=0 && buf[i]!='\r' && buf[i]!='\n' ; ++i )
+		parse_string += buf[i];
+}
+
+
+void GetParseString()
+{
+int line;
+
+	parse_string.clear();
+
+	// index of a last line to parse (-1 because the ENTER has been put)
+	line = SendMessage(edit, EM_LINEFROMCHAR, -1, 0) - 1;
+
+	if( line < 0 )
+		// something wrong
+		return;
+
+
+	HLOCAL handle = (HLOCAL)SendMessage(edit, EM_GETHANDLE, 0, 0);
+
+	if( handle == 0 )
+		// something wrong
+		return;
+
+	const char * buf = (const char*)LocalLock(handle);
+	
+	if( buf )
+		GetParseString(buf, line);
+
+	LocalUnlock(handle);
+}
+
+
+template<class ValueType>
+void ParseString(ttmath::Parser<ValueType> & matparser)
+{
+	matparser.SetBase(base_input);
+	matparser.SetDegRadGrad(angle_deg_rad_grad);
+	matparser.SetFunctions(functions);
+	matparser.SetVariables(variables);
+
+	code = matparser.Parse(parse_string.c_str());
+
+	calculated = matparser.Calculated();
+}
+
+
+void SetParameters()
+{
+	base_input         = GetPrgRes()->GetBaseInput();
+	base_output        = GetPrgRes()->GetBaseOutput();
+	always_scientific  = GetPrgRes()->GetDisplayAlwaysScientific();
+	when_scientific    = GetPrgRes()->GetDisplayWhenScientific();
+	rounding           = GetPrgRes()->GetDisplayRounding();
+	precision          = GetPrgRes()->GetPrecision();
+	remove_zeroes      = GetPrgRes()->GetRemovingZeroes();
+	angle_deg_rad_grad = GetPrgRes()->GetDegRadGrad();
+	country            = GetPrgRes()->GetLanguages()->GetCurrentLanguage();
+
+	if( GetPrgRes()->GetDecimalPoint() == 0 )
+		decimal_point = '.';
+	else
+		decimal_point = ',';
+
+	variables = GetPrgRes()->GetVariables();
+	functions = GetPrgRes()->GetFunctions();
+}
+
+	
+void ParseString()
+{
+	if( parse_string.empty() )
+		return;
+	
+	SetParameters();
+
+	try
+	{
+	#ifndef TTCALC_PORTABLE
+
+		switch( precision )
+		{
+		case 0:
+			ParseString(parser1);
+			break;
+
+		case 1:
+			ParseString(parser2);
+			break;
+
+		default:
+			ParseString(parser3);
+			break;
+		}
+
+	#else
+		ParseString(parser1);
+	#endif
+	}
+	catch(...)
+	{
+		code = ttmath::err_internal_error;
+	}
+
+
+	if( code==ttmath::err_ok && calculated )
+		PutResult();
+	else
+	if( code==ttmath::err_overflow )
+		PutOverflowMsg();
+}
+
+
+LRESULT EditReturnPressed(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+DWORD sel_start, sel_end;
+
+	SendMessage(edit, EM_GETSEL, (WPARAM)&sel_start, (LPARAM)&sel_end);
+		
+	if( sel_start != sel_end )
+		// something is selected
+		return CallWindowProc(old_edit_proc, hwnd, msg, wParam, lParam);
+
+	// putting the ENTER
+	LRESULT res = CallWindowProc(old_edit_proc, hwnd, msg, wParam, lParam);
+
+	GetParseString();
+	ParseString();
+
+return res;
+}
+
+
+
+LRESULT EditSubclass(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+	switch( msg )
+	{
+	case WM_CHAR:
+		if( wParam == VK_RETURN )
+		{
+			return EditReturnPressed(hwnd, msg, wParam, lParam);
+		}
+		break;
+	}
+
+return CallWindowProc(old_edit_proc, hwnd, msg, wParam, lParam);
+}
+
+
+
+
+LRESULT PadCreate(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+	edit = CreateWindow("edit", "",
+			WS_VISIBLE | WS_CHILD | WS_VSCROLL | ES_MULTILINE | ES_AUTOVSCROLL,
+			0, 0, 100, 100, hwnd, 0, GetPrgRes()->GetInstance(), 0);
+
+	old_edit_proc = (WNDPROC)SetWindowLong(edit, GWL_WNDPROC, (LONG)EditSubclass);
+
+	return 0;
+}
+
+
+LRESULT PadSize(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+int cx = LOWORD(lParam);
+int cy = HIWORD(lParam);
+
+	MoveWindow(edit, 0, 0, cx, cy, true);
+
+return 0;
+}
+
+
+
+LRESULT PadClose(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+	GetPrgRes()->TurnPad();
+
+return 0;
+}
+
+
+LRESULT PadFocus(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+	SetFocus(edit);
+
+return 0;
+}
+
+
+void CreatePadMessagesTable(Messages<LRESULT> & messages)
+{
+	messages.Associate(WM_CREATE,   PadCreate);
+	messages.Associate(WM_SIZE,     PadSize);
+	messages.Associate(WM_CLOSE,    PadClose);
+	messages.Associate(WM_SETFOCUS, PadFocus);
+}
+
+
+LRESULT CALLBACK WindowPadProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+static Messages<LRESULT> messages;
+bool method_exists;
+LRESULT res;
+
+	if( messages.Empty() )
+		// initiation
+		CreatePadMessagesTable(messages);
+
+	res = messages.Call(msg, hwnd, msg, wParam, lParam, &method_exists);
+
+	if( !method_exists )
+		return DefWindowProc(hwnd, msg, wParam, lParam);
+
+return res;
+}
+
+
+
+ATOM RegisterPadClass(const char * ttcalc_pad_class_name)
+{
+WNDCLASS w;
+
+	w.style         = 0;
+	w.lpfnWndProc   = WindowPadProc;
+	w.cbClsExtra    = 0;
+	w.cbWndExtra    = 0;
+	w.hInstance     = GetPrgRes()->GetInstance();
+	w.hIcon         = LoadIcon(GetPrgRes()->GetInstance(), MAKEINTRESOURCE(IDI_ICON2));
+	w.hCursor       = 0;
+	w.hbrBackground = (HBRUSH)(COLOR_BACKGROUND+1);
+	w.lpszMenuName  = 0;
+	w.lpszClassName = ttcalc_pad_class_name;
+
+return RegisterClass(&w);
+}
+
+
+} // namespace Pad
+
+
+
+
+
+bool CreatePadWindow()
+{
+using namespace Pad;
+
+static char ttcalc_pad_class_name[] = "TTCalcPadWindow";
+
+ATOM a = RegisterPadClass(ttcalc_pad_class_name);
+
+	if( a == 0 )
+		return false;
+
+	HWND pad = CreateWindowEx(0, ttcalc_pad_class_name,
+				"Pad",
+				WS_OVERLAPPEDWINDOW | WS_POPUPWINDOW ,
+				100, 100,
+				600, 450,
+				GetPrgRes()->GetMainWindow(), 0, GetPrgRes()->GetInstance(), 0);
+
+
+	GetPrgRes()->SetPadWindow(pad);
+
+
+return pad != 0;
+}
+
+
+
+
diff --git a/src/pad.h b/src/pad.h
new file mode 100644
index 0000000..ec2daae
--- /dev/null
+++ b/src/pad.h
@@ -0,0 +1,47 @@
+/*
+ * This file is a part of TTCalc - a mathematical calculator
+ * and is distributed under the (new) BSD licence.
+ * Author: Tomasz Sowa <t.sowa@slimaczek.pl>
+ */
+
+/* 
+ * Copyright (c) 2006-2009, Tomasz Sowa
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *    
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *    
+ *  * Neither the name Tomasz Sowa nor the names of contributors to this
+ *    project may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef headerfilepad
+#define headerfilepad
+
+
+
+bool CreatePadWindow();
+
+
+
+#endif