diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6b0b01aa86..0977347f35 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,6 +29,9 @@ option(KICAD_GOST "enable/disable building using GOST notation for multiple gate
 #for those who bored with uppercase
 option(KICAD_KEEPCASE "turn-off automatic component name conversion to uppercase if selected")
 
+#highly experimetnal option
+option(KICAD_NANOMETRE "set length quantum to 1 nm for PCB")
+
 option(USE_WX_GRAPHICS_CONTEXT
        "Use wxGraphicsContext for rendering (default OFF). Warning, this is experimental")
 
@@ -99,6 +102,10 @@ if(KICAD_KEEPCASE)
     add_definitions(-DKICAD_KEEPCASE)
 endif(KICAD_KEEPCASE)
 
+if(KICAD_NANOMETRE)
+    add_definitions(-DKICAD_NANOMETRE)
+endif(KICAD_NANOMETRE)
+
 if(USE_WX_OVERLAY OR APPLE)
     add_definitions(-DUSE_WX_OVERLAY)
 endif(USE_WX_OVERLAY OR APPLE)
diff --git a/common/common.cpp b/common/common.cpp
index 37d9c41a87..af58602152 100644
--- a/common/common.cpp
+++ b/common/common.cpp
@@ -441,6 +441,133 @@ int ReturnValueFromString( EDA_UNITS_T aUnit, const wxString& TextValue,
 }
 
 
+#ifdef KICAD_NANOMETRE
+
+/*
+ *New common length functions
+ */
+
+const LENGTH_UNIT_DESC g_MillimetreDesc =
+{
+    LENGTH_UNITS<LENGTH_DEF>::millimetre(),
+    _(" mm"),
+    wxT("mm"),
+    6
+};
+const LENGTH_UNIT_DESC g_InchDesc =
+{
+    LENGTH_UNITS<LENGTH_DEF>::inch(),
+    _(" \""),
+    wxT("in"),
+    7
+};
+const LENGTH_UNIT_DESC g_MilDesc =
+{
+    LENGTH_UNITS<LENGTH_DEF>::mil(),
+    _(" mil"),
+    wxT("mil"),
+    5
+};
+const LENGTH_UNIT_DESC g_UnscaledDesc = /* stub */
+{
+    LENGTH_DEF::quantum(),
+    wxT(""),
+    wxT(""),
+    4
+};
+
+const LENGTH_UNIT_DESC *UnitDescription( EDA_UNITS_T aUnit ) {
+    switch(aUnit) {
+        case INCHES:
+            return &g_InchDesc;
+        case MILLIMETRES:
+            return &g_MillimetreDesc;
+        default:
+            return &g_UnscaledDesc; /* should not be reached */
+    }
+}
+
+wxString LengthToString( const LENGTH_UNIT_DESC *aUnit, LENGTH_DEF aValue,
+                         bool aAdd_unit_symbol ) {
+    wxString StringValue;
+    double   value_to_print;
+    value_to_print = LENGTH<double>(aValue) / LENGTH<double>(aUnit->m_Value);
+    StringValue.Printf( wxT( "%.*f" ), aUnit->m_Precision, value_to_print);
+    if( aAdd_unit_symbol ) {
+        StringValue += aUnit->m_Postfix;
+    }
+    return StringValue;
+}
+LENGTH_DEF StringToLength( const LENGTH_UNIT_DESC *aUnit, const wxString& TextValue )
+{
+
+    LENGTH_DEF    Value;
+    double dtmp = 0;
+
+    /* Acquire the 'right' decimal point separator */
+    const struct lconv* lc = localeconv();
+    wxChar decimal_point = lc->decimal_point[0];
+    wxString            buf( TextValue.Strip( wxString::both ) );
+
+    /* Convert the period in decimal point */
+    buf.Replace( wxT( "." ), wxString( decimal_point, 1 ) );
+    // An ugly fix needed by WxWidgets 2.9.1 that sometimes
+    // back to a point as separator, although the separator is the comma
+    // TODO: remove this line if WxWidgets 2.9.2 fixes this issue
+    buf.Replace( wxT( "," ), wxString( decimal_point, 1 ) );
+
+    /* Find the end of the numeric part */
+    unsigned brk_point = 0;
+    while( brk_point < buf.Len() )
+    {
+        wxChar ch = buf[brk_point];
+        if( !( (ch >= '0' && ch <='9') || (ch == decimal_point)
+             || (ch == '-') || (ch == '+') ) )
+        {
+            break;
+        }
+        ++brk_point;
+    }
+
+    /* Extract the numeric part */
+    buf.Left( brk_point ).ToDouble( &dtmp );
+
+    /* Check the optional unit designator (2 ch significant) */
+    wxString unit( buf.Mid( brk_point ).Strip( wxString::leading ).Left( 2 ).Lower() );
+    if( unit == wxT( "in" ) || unit == wxT( "\"" ) )
+    {
+        aUnit = &g_InchDesc;
+    }
+    else if( unit == wxT( "mm" ) )
+    {
+        aUnit = &g_MillimetreDesc;
+    }
+    else if( unit == wxT( "mi" ) || unit == wxT( "th" ) ) /* Mils or thous */
+    {
+        aUnit = &g_MilDesc;
+    }
+    Value = LENGTH_DEF( dtmp * LENGTH< double, 1 >( aUnit->m_Value ) );
+
+    return Value;
+}
+
+void LengthToTextCtrl( wxTextCtrl& TextCtr, LENGTH_DEF Value ) {
+    wxString msg = LengthToString( UnitDescription( g_UserUnit ), Value );
+
+    TextCtr.SetValue( msg );
+}
+LENGTH_DEF LengthFromTextCtrl( const wxTextCtrl& TextCtr )
+{
+    LENGTH_DEF value;
+    wxString msg = TextCtr.GetValue();
+
+    value = StringToLength( UnitDescription( g_UserUnit ), msg );
+
+    return value;
+}
+
+#endif
+
 /**
  * Function wxStringSplit
  * Split a String to a String List when founding 'splitter'
diff --git a/include/class_board_design_settings.h b/include/class_board_design_settings.h
index af7b255f73..fc558bc4b2 100644
--- a/include/class_board_design_settings.h
+++ b/include/class_board_design_settings.h
@@ -7,6 +7,8 @@
 
 #include "pcbstruct.h"      // NB_COLORS
 
+#include "lengthpcb.h"
+
 // Class for handle current printed board design settings
 class BOARD_DESIGN_SETTINGS
 {
@@ -22,11 +24,11 @@ public:
     int    m_EdgeSegmentWidth;            // current graphic line width (EDGE layer only)
     int    m_PcbTextWidth;                // current Pcb (not module) Text width
     wxSize m_PcbTextSize;                 // current Pcb (not module) Text size
-    int    m_TrackMinWidth;               // track min value for width ((min copper size value
-    int    m_ViasMinSize;                 // vias (not micro vias) min diameter
-    int    m_ViasMinDrill;                // vias (not micro vias) min drill diameter
-    int    m_MicroViasMinSize;            // micro vias (not vias) min diameter
-    int    m_MicroViasMinDrill;           // micro vias (not vias) min drill diameter
+    LENGTH_PCB m_TrackMinWidth;               // track min value for width ((min copper size value
+    LENGTH_PCB m_ViasMinSize;                 // vias (not micro vias) min diameter
+    LENGTH_PCB m_ViasMinDrill;                // vias (not micro vias) min drill diameter
+    LENGTH_PCB m_MicroViasMinSize;            // micro vias (not vias) min diameter
+    LENGTH_PCB m_MicroViasMinDrill;           // micro vias (not vias) min drill diameter
 
     // Global mask margins:
     int    m_SolderMaskMargin;            // Solder mask margin
diff --git a/include/common.h b/include/common.h
index eb22f5878e..e28d5e54a5 100644
--- a/include/common.h
+++ b/include/common.h
@@ -10,6 +10,11 @@
 #include "wx/confbase.h"
 #include "wx/fileconf.h"
 
+
+#ifdef KICAD_NANOMETRE
+#include "length.h"
+#endif
+
 class wxAboutDialogInfo;
 class BASE_SCREEN;
 class EDA_DRAW_FRAME;
@@ -321,6 +326,7 @@ wxString        ReturnStringFromValue( EDA_UNITS_T aUnit,
                                        int  aInternal_Unit,
                                        bool aAdd_unit_symbol = false );
 
+
 void            AddUnitSymbol( wxStaticText& Stext, EDA_UNITS_T aUnit = g_UserUnit );
 
 /* Add string "  (mm):" or " ("):" to the static text Stext.
@@ -334,6 +340,27 @@ void            PutValueInLocalUnits( wxTextCtrl& TextCtr, int Value,
 int             ReturnValueFromTextCtrl( const wxTextCtrl& TextCtr,
                                          int               Internal_Unit );
 
+#ifdef KICAD_NANOMETRE
+
+struct LENGTH_UNIT_DESC
+{
+    LENGTH_DEF m_Value;
+    wxString   m_Postfix;
+    wxString   m_IntlSymbol;
+    int        m_Precision;
+};
+extern const LENGTH_UNIT_DESC g_MillimetreDesc, g_InchDesc, g_MilDesc;
+
+const LENGTH_UNIT_DESC *UnitDescription( EDA_UNITS_T aUnit );
+
+LENGTH_DEF       StringToLength( const LENGTH_UNIT_DESC *aUnit, const wxString& TextValue );
+wxString         LengthToString( const LENGTH_UNIT_DESC *aUnit, LENGTH_DEF aValue,
+                                 bool aAdd_unit_symbol = false );
+
+void             LengthToTextCtrl( wxTextCtrl& TextCtr, LENGTH_DEF Value );
+LENGTH_DEF       LengthFromTextCtrl( const wxTextCtrl& TextCtr );
+#endif
+
 /* return a String List from a string, with a specific splitter*/
 wxArrayString*  wxStringSplit( wxString txt, wxChar splitter );
 
diff --git a/include/length.h b/include/length.h
index 537b01dacb..c72218f244 100644
--- a/include/length.h
+++ b/include/length.h
@@ -1,18 +1,20 @@
 /**
- * The physical length library. Made for nanometer scale.
  * @file length.h
+ * @brief The physical length library. Made for nanometer scale.
  */
 
-/* sorry it is not styled correctly, i'll work on it further */
+/* sorry if it is not styled correctly, i'll work on it further */
 
 #ifndef LENGTH_H_INCLUDED
 #define LENGTH_H_INCLUDED 1
 
+#include "limited_int.h"
+
 /* type to be used by length units by default */
-typedef int DEF_LENGTH_VALUE;
+typedef LIMITED_INT< int > DEF_LENGTH_VALUE;
 
 /**
- * Length template class
+ * Length template class.
  * @param T actual type holding a value (be aware of precision and range!)
  * @param P power of length unit: 1 - length, 2 - area, 3 - volume, -1 - lin. density etc...
  * This class check length dimension in compile time. In runtime it behaves
@@ -47,6 +49,8 @@ typedef int DEF_LENGTH_VALUE;
 
 template < typename T = DEF_LENGTH_VALUE, int P = 1 > class LENGTH;
 
+typedef LENGTH<DEF_LENGTH_VALUE, 1> LENGTH_DEF;
+
 /**
  * Length units contained in this class
  */
@@ -61,6 +65,38 @@ template < typename T, int P > struct LENGTH_TRAITS
     typedef LENGTH<T, P> flat;
 };
 
+template < typename T > struct LENGTH_CASTS
+{
+     template< typename X > static T cast( const X x )
+     {
+         return T( x );
+     }
+};
+
+template <> struct LENGTH_CASTS < int >
+{
+     static int cast( const double x )
+     {
+         return floor( x + 0.5 );
+     }
+};
+
+template <> struct LENGTH_CASTS < long >
+{
+     static long cast( const double x )
+     {
+         return floor( x + 0.5 );
+     }
+};
+
+template < typename T > struct LENGTH_CASTS < LIMITED_INT< T > >
+{
+     static LIMITED_INT< T > cast( const double x )
+     {
+         return LIMITED_INT< T > ( floor( x + 0.5 ) );
+     }
+};
+
 template < typename T > struct LENGTH_TRAITS< T, 0 >
 {
     /* length dimension to power 0 is just a number, so LENGTH<T, 0> should be automatically converted to T */
@@ -92,7 +128,8 @@ public:
     {
         dimension = P
     };
-    LENGTH( const LENGTH <T, P> &orig ) : m_U( orig.m_U )
+    template< typename U > LENGTH( const LENGTH< U, P > &orig )
+    : m_U( LENGTH_CASTS < T >::cast( orig.m_U ) )
     {
     }
     LENGTH( void ) : m_U()
@@ -104,14 +141,20 @@ public:
         return T(0);
     }
 
+    /* Do not use this, please */
+    static LENGTH<T, P> quantum ( void )
+    {
+        return T(1);
+    }
+
     LENGTH<T, P> & operator = ( const LENGTH<T, P> & y )
     {
         this->m_U = y.m_U;
         return *this;
     }
-    template<typename Y> operator LENGTH< Y, P > ( void )
+    template< typename Y > operator LENGTH< Y, P > ( void )
     {
-        return this->m_U;
+        return LENGTH< Y, P >( this->m_U );
     }
     /*************************/
     /* comparisons and tests */
@@ -231,6 +274,9 @@ public:
  * to get numeric value of length in specific units you should use a division
  * length/LENGTH_UNITS::metre() gives number of metres in length
  * legnth/LENGTH_UNITS::foot() gives number of feet in length
+ *
+ * Really these units are used in NEWPCB and printing routines, as EESCHEMA
+ * is going to use relative units.
  */
 
 template < typename T = DEF_LENGTH_VALUE > class LENGTH_UNITS {
@@ -275,4 +321,4 @@ template < typename T, int D > class LENGTH_UNITS< LENGTH< T, D > >: public LENG
 {
 };
 
-#endif
+#endif /* def LENGTH_H_INCLUDED */
diff --git a/include/lengthpcb.h b/include/lengthpcb.h
new file mode 100644
index 0000000000..98bebea342
--- /dev/null
+++ b/include/lengthpcb.h
@@ -0,0 +1,58 @@
+/**
+ * @file lengthpcb.h
+ * @brief Length definitions for PCBNEW.
+ */
+
+#ifndef LENGTHPCB_H_INCLUDED
+#define LENGTHPCB_H_INCLUDED 1
+
+#ifdef KICAD_NANOMETRE
+#include "length.h"
+
+/* switched type! */
+typedef LENGTH< LIMITED_INT< int >, 1 > LENGTH_PCB;
+typedef LENGTH< double, 1 > LENGTH_PCB_DBL;
+
+/* Transition macros. they are used for unit conversion between
+ * nanometre scale and old (0.1 mil) scale */
+
+#define PCB_LEGACY_INCH_SCALE 10000
+#define PCB_LEGACY_UNIT( T ) ( LENGTH_UNITS< T >::inch() / PCB_LEGACY_INCH_SCALE )
+
+#define TO_LEGACY_LU( x )      \
+  (     LENGTH_PCB( x ) / PCB_LEGACY_UNIT( LENGTH_PCB     ) )
+#define TO_LEGACY_LU_DBL( x )  \
+  ( LENGTH_PCB_DBL( x ) / PCB_LEGACY_UNIT( LENGTH_PCB_DBL ) )
+
+static LENGTH_PCB from_legacy_lu( int x ) {
+	return x * PCB_LEGACY_UNIT( LENGTH_PCB );
+}
+static LENGTH_PCB from_legacy_lu( double x ) {
+	return LENGTH_PCB( x * PCB_LEGACY_UNIT( LENGTH_PCB_DBL ) );
+}
+
+static LENGTH_PCB_DBL from_legacy_lu_dbl( double x ) {
+	return x * LENGTH_UNITS< LENGTH_PCB_DBL >::inch() / PCB_LEGACY_INCH_SCALE;
+}
+
+#define FROM_LEGACY_LU( x )     ( from_legacy_lu( x ) )
+#define FROM_LEGACY_LU_DBL( x ) ( from_legacy_lu_dbl( x ) )
+
+
+#else
+
+typedef int LENGTH_PCB;
+typedef double LENGTH_PCB_DBL;
+
+/* transition macro stubs */
+
+#define TO_LEGACY_LU( x )               ( x )
+#define TO_LEGACY_LU_DBL( x )   ( double( x ) )
+
+#define FROM_LEGACY_LU( x )             ( x )
+#define FROM_LEGACY_LU_DBL( x ) ( double( x ) )
+
+#endif
+
+
+#endif /* def LENGTHPCB_H_INCLUDED */
diff --git a/include/limited_int.h b/include/limited_int.h
new file mode 100644
index 0000000000..67d9fb8d2a
--- /dev/null
+++ b/include/limited_int.h
@@ -0,0 +1,309 @@
+/**
+ * @file limited_int.h
+ * @brief Integer class catching overflows.
+ */
+
+/* sorry if it is not styled correctly, i'll work on it further */
+
+#ifndef LIMITED_INT_H_INCLUDED
+#define LIMITED_INT_H_INCLUDED 1
+
+#include <limits>
+#include <assert.h>
+#include <math.h>
+
+template < typename T = int > class LIMITED_INT {
+private:
+    T m_Value;
+public:
+    LIMITED_INT( void ) : m_Value() {
+    }
+    template<typename V> LIMITED_INT( const LIMITED_INT< V >& orig )
+    :  m_Value( orig.m_Value )
+    {
+        assert(std::numeric_limits<T>::min() <= orig.m_Value);
+        assert(orig.m_Value <= std::numeric_limits<T>::max());
+    }
+    template<typename V> LIMITED_INT( const double v )
+    :  m_Value( floor(v+0.5) )
+    {
+        assert(std::numeric_limits<T>::min() <= v);
+        assert(v <= std::numeric_limits<T>::max());
+    }
+    LIMITED_INT( T v ): m_Value( v )
+    {
+    }
+
+    operator T( void ) const
+    {
+        return m_Value;
+    }
+    operator double( void ) const
+    {
+        return ( double )m_Value;
+    }
+
+    LIMITED_INT<T> & operator = ( LIMITED_INT< T > src )
+    {
+        m_Value = src.m_Value;
+        return *this;
+    }
+    LIMITED_INT<T> & operator = ( T src )
+    {
+        m_Value = src;
+        return *this;
+    }
+    /*************************/
+    /* comparisons and tests */
+    /*************************/
+    bool operator ! (void) const {
+	    return !m_Value;
+    }
+    
+    bool operator == ( const LIMITED_INT< T > &y ) const
+    {
+        return m_Value == y.m_Value;
+    }
+    bool operator == ( const T y ) const
+    {
+        return m_Value == y;
+    }
+    friend bool operator == ( const T x, const LIMITED_INT< T > &y )
+    {
+        return x == y.m_Value;
+    }
+
+    bool operator != ( const LIMITED_INT<T> &y ) const
+    {
+        return m_Value != y.m_Value;
+    }
+    bool operator != ( const T y ) const
+    {
+        return m_Value != y;
+    }
+    friend bool operator != ( const T x, const LIMITED_INT< T > &y )
+    {
+        return x != y.m_Value;
+    }
+
+    bool operator < ( const LIMITED_INT< T > &y ) const
+    {
+        return m_Value < y.m_Value;
+    }
+    bool operator < ( const T y ) const
+    {
+        return m_Value < y;
+    }
+    friend bool operator < ( const T x, const LIMITED_INT< T > &y )
+    {
+        return x < y.m_Value;
+    }
+
+    bool operator >= ( const LIMITED_INT< T > &y ) const
+    {
+        return m_Value >= y.m_Value;
+    }
+    bool operator >= ( const T y ) const
+    {
+        return m_Value >= y;
+    }
+    friend bool operator >= ( const T x, const LIMITED_INT<T> &y )
+    {
+        return x >= y.m_Value;
+    }
+
+    bool operator > ( const LIMITED_INT< T > &y ) const
+    {
+        return m_Value > y.m_Value;
+    }
+    bool operator > ( const T y ) const
+    {
+        return m_Value > y;
+    }
+    friend bool operator > ( const T x, const LIMITED_INT< T > &y )
+    {
+        return x > y.m_Value;
+    }
+
+    bool operator <= ( const LIMITED_INT< T > &y ) const
+    {
+        return m_Value <= y.m_Value;
+    }
+    bool operator <= ( const T y ) const
+    {
+        return m_Value <= y;
+    }
+    friend bool operator <= ( const T x, const LIMITED_INT< T > &y )
+    {
+        return x <= y.m_Value;
+    }
+
+    /*************************/
+    /* basic arithmetic      */
+    /*************************/
+    LIMITED_INT< T > operator + ( const LIMITED_INT< T > &y ) const
+    {
+        assert( !( 0 < m_Value ) || y.m_Value <= std::numeric_limits< T >::max() - m_Value );
+        assert( !( m_Value < 0 ) || std::numeric_limits< T >::min() - m_Value <= y.m_Value );
+        return m_Value + y.m_Value;
+    }
+    LIMITED_INT< T > operator + ( const T y ) const
+    {
+        return *this + LIMITED_INT< T >( y );
+    }
+    friend LIMITED_INT< T > operator + ( const T x, const LIMITED_INT< T > &y )
+    {
+        return LIMITED_INT< T >( x ) + y;
+    }
+    double operator + ( const double y ) const
+    {
+        return double( m_Value ) + y;
+    }
+    friend double operator + ( const double x, const LIMITED_INT< T > &y )
+    {
+        return x + double( y.m_Value );
+    }
+
+    LIMITED_INT< T > operator - ( const LIMITED_INT< T > &y ) const
+    {
+        assert( !( 0 < m_Value ) || m_Value - std::numeric_limits< T >::max() <= y.m_Value );
+        assert( !( m_Value < 0 ) || y.m_Value <= m_Value - std::numeric_limits< T >::min() );
+        return m_Value - y.m_Value;
+    }
+    LIMITED_INT< T > operator - ( const T y ) const
+    {
+        return *this - LIMITED_INT< T >( y );
+    }
+    friend LIMITED_INT< T > operator - ( const T x, const LIMITED_INT< T > &y )
+    {
+        return LIMITED_INT< T >( x ) - y;
+    }
+    double operator - ( const double y ) const
+    {
+        return double( m_Value ) - y;
+    }
+    friend double operator - ( const double x, const LIMITED_INT< T > &y )
+    {
+        return x - double( y.m_Value );
+    }
+
+    LIMITED_INT< T > operator * ( const LIMITED_INT< T > &y ) const
+    {
+        assert( !( 0 < m_Value && 0 < y.m_Value )
+        || y.m_Value <= std::numeric_limits<T>::max() / m_Value );
+        assert( !( 0 < m_Value && y.m_Value < 0 )
+        || std::numeric_limits<T>::min() / m_Value <= y.m_Value );
+        assert( !( m_Value < 0 && 0 < y.m_Value )
+        || std::numeric_limits<T>::min() / y.m_Value <= m_Value );
+        assert( !( m_Value < 0 && y.m_Value < 0 )
+        || std::numeric_limits<T>::max() / m_Value <= y.m_Value );
+        return m_Value * y.m_Value;
+    }
+    LIMITED_INT<T> operator * ( const T y) const
+    {
+        return *this * LIMITED_INT< T >( y );
+    }
+    friend LIMITED_INT< T > operator *( const T x, const LIMITED_INT< T > &y )
+    {
+        return LIMITED_INT< T >( x ) * y;
+    }
+    double operator * ( const double y ) const
+    {
+        return double( m_Value ) * y;
+    }
+    friend double operator * ( const double x, const LIMITED_INT< T > &y )
+    {
+        return x * double( y.m_Value );
+    }
+
+    LIMITED_INT<T> operator / ( const LIMITED_INT<T> &y ) const
+    {
+        assert( !( -1 == y.m_Value )
+        || -std::numeric_limits< T >::max() <= m_Value );
+        return m_Value / y.m_Value;
+    }
+    LIMITED_INT<T> operator / ( const T y ) const
+    {
+        return *this / LIMITED_INT<T>(y);
+    }
+    friend LIMITED_INT< T > operator / ( const T x, const LIMITED_INT< T > &y )
+    {
+        return LIMITED_INT< T >( x ) / y;
+    }
+    double operator / ( const double y ) const
+    {
+        return double( m_Value ) / y;
+    }
+    friend double operator / ( const double x, const LIMITED_INT< T > &y )
+    {
+        return x / double( y.m_Value );
+    }
+    
+    LIMITED_INT<T> operator % ( const LIMITED_INT<T> &y ) const
+    {
+        return m_Value % y.m_Value;
+    }
+    LIMITED_INT<T> operator % ( const T y ) const
+    {
+        return *this % LIMITED_INT<T>(y);
+    }
+    friend LIMITED_INT< T > operator % ( const T x, const LIMITED_INT< T > &y )
+    {
+        return LIMITED_INT< T >( x ) % y;
+    }
+    /*************************/
+    /* assignment arithmetic */
+    /*************************/
+    LIMITED_INT< T >& operator += ( const LIMITED_INT< T > &y )
+    {
+        *this = *this + y;
+        return *this;
+    }
+    LIMITED_INT< T >& operator += ( const T y )
+    {
+        *this = *this + y;
+        return *this;
+    }
+    LIMITED_INT< T >& operator ++ ( void )
+    {
+        *this = *this + 1;
+        return *this;
+    }
+    LIMITED_INT< T >& operator -= ( const LIMITED_INT< T > &y )
+    {
+        *this = *this - y;
+        return *this;
+    }
+    LIMITED_INT< T >& operator -= ( const T y )
+    {
+        *this = *this - y;
+        return *this;
+    }
+    LIMITED_INT< T >& operator -- ( void )
+    {
+        *this = *this - 1;
+        return *this;
+    }
+    LIMITED_INT< T >& operator *= ( const LIMITED_INT< T > &y )
+    {
+        *this = *this * y;
+        return *this;
+    }
+    LIMITED_INT< T >& operator *= ( const T y )
+    {
+        *this = *this * y;
+        return *this;
+    }
+    LIMITED_INT< T >& operator /= ( const LIMITED_INT< T > &y )
+    {
+        *this = *this / y;
+        return *this;
+    }
+    LIMITED_INT< T >& operator /= ( const T y )
+    {
+        *this = *this / y;
+        return *this;
+    }
+};
+
+#endif /* def LIMITED_INT_H_INCLUDED*/
diff --git a/pcbnew/class_board_design_settings.cpp b/pcbnew/class_board_design_settings.cpp
index 1950c32978..9bcaea4cec 100644
--- a/pcbnew/class_board_design_settings.cpp
+++ b/pcbnew/class_board_design_settings.cpp
@@ -32,11 +32,11 @@ BOARD_DESIGN_SETTINGS::BOARD_DESIGN_SETTINGS()
     m_EdgeSegmentWidth = 100;                   // current graphic line width (EDGE layer only)
     m_PcbTextWidth     = 100;                   // current Pcb (not module) Text width
     m_PcbTextSize       = wxSize( 500, 500 );   // current Pcb (not module) Text size
-    m_TrackMinWidth     = 80;                   // track min value for width ((min copper size value
-    m_ViasMinSize       = 350;                  // vias (not micro vias) min diameter
-    m_ViasMinDrill      = 200;                  // vias (not micro vias) min drill diameter
-    m_MicroViasMinSize  = 200;                  // micro vias (not vias) min diameter
-    m_MicroViasMinDrill = 50;                   // micro vias (not vias) min drill diameter
+    m_TrackMinWidth     = FROM_LEGACY_LU( 80 );  // track min value for width ((min copper size value
+    m_ViasMinSize       = FROM_LEGACY_LU( 350 ); // vias (not micro vias) min diameter
+    m_ViasMinDrill      = FROM_LEGACY_LU( 200 ); // vias (not micro vias) min drill diameter
+    m_MicroViasMinSize  = FROM_LEGACY_LU( 200 ); // micro vias (not vias) min diameter
+    m_MicroViasMinDrill = FROM_LEGACY_LU( 50 );  // micro vias (not vias) min drill diameter
 
     // Global mask margins:
     m_SolderMaskMargin  = 150;                  // Solder mask margin
diff --git a/pcbnew/class_netclass.cpp b/pcbnew/class_netclass.cpp
index 2f10f27553..187ce9d977 100644
--- a/pcbnew/class_netclass.cpp
+++ b/pcbnew/class_netclass.cpp
@@ -75,9 +75,9 @@ void NETCLASS::SetParams( const NETCLASS* defaults )
         // TODO: see how change that.
         const BOARD_DESIGN_SETTINGS& g = boardDesignSettings;
 
-        SetTrackWidth(  g.m_TrackMinWidth );
-        SetViaDiameter( g.m_ViasMinSize );
-        SetuViaDiameter(g.m_MicroViasMinSize );
+        SetTrackWidth(  TO_LEGACY_LU( g.m_TrackMinWidth ) );
+        SetViaDiameter( TO_LEGACY_LU( g.m_ViasMinSize ) );
+        SetuViaDiameter( TO_LEGACY_LU( g.m_MicroViasMinSize ) );
         // Use default values for next parameters:
         SetClearance( DEFAULT_CLEARANCE );
         SetViaDrill( DEFAULT_VIA_DRILL );
@@ -412,27 +412,27 @@ bool NETCLASS::ReadDescr( LINE_READER* aReader )
 
 int NETCLASS::GetTrackMinWidth() const
 {
-    return m_Parent->GetBoardDesignSettings()->m_TrackMinWidth;
+    return TO_LEGACY_LU( m_Parent->GetBoardDesignSettings()->m_TrackMinWidth );
 }
 
 int NETCLASS::GetViaMinDiameter() const
 {
-    return m_Parent->GetBoardDesignSettings()->m_ViasMinSize;
+    return TO_LEGACY_LU( m_Parent->GetBoardDesignSettings()->m_ViasMinSize );
 }
 
 int NETCLASS::GetViaMinDrill() const
 {
-    return m_Parent->GetBoardDesignSettings()->m_ViasMinDrill;
+    return TO_LEGACY_LU( m_Parent->GetBoardDesignSettings()->m_ViasMinDrill );
 }
 
 int NETCLASS::GetuViaMinDiameter() const
 {
-    return m_Parent->GetBoardDesignSettings()->m_MicroViasMinSize;
+    return TO_LEGACY_LU( m_Parent->GetBoardDesignSettings()->m_MicroViasMinSize );
 }
 
 int NETCLASS::GetuViaMinDrill() const
 {
-    return m_Parent->GetBoardDesignSettings()->m_MicroViasMinDrill;
+    return TO_LEGACY_LU( m_Parent->GetBoardDesignSettings()->m_MicroViasMinDrill );
 }
 
 
diff --git a/pcbnew/dialogs/dialog_design_rules.cpp b/pcbnew/dialogs/dialog_design_rules.cpp
index 8cd8ff62ad..313eb2b1e5 100644
--- a/pcbnew/dialogs/dialog_design_rules.cpp
+++ b/pcbnew/dialogs/dialog_design_rules.cpp
@@ -213,18 +213,21 @@ void DIALOG_DESIGN_RULES::PrintCurrentSettings()
 
     // Display min values:
     value = ReturnStringFromValue( g_UserUnit,
-                                   m_BrdSettings->m_TrackMinWidth,
+                                   TO_LEGACY_LU( m_BrdSettings->m_TrackMinWidth ),
                                    internal_units,
                                    true );
     msg.Printf( _( "Minimum value for tracks width: <b>%s</b><br>\n" ), GetChars( value ) );
     m_MessagesList->AppendToPage( msg );
 
-    value = ReturnStringFromValue( g_UserUnit, m_BrdSettings->m_ViasMinSize, internal_units, true );
+    value = ReturnStringFromValue( g_UserUnit,
+                                   TO_LEGACY_LU( m_BrdSettings->m_ViasMinSize ),
+                                   internal_units,
+                                   true );
     msg.Printf( _( "Minimum value for vias diameter: <b>%s</b><br>\n" ), GetChars( value ) );
     m_MessagesList->AppendToPage( msg );
 
     value = ReturnStringFromValue( g_UserUnit,
-                                   m_BrdSettings->m_MicroViasMinSize,
+                                   TO_LEGACY_LU( m_BrdSettings->m_MicroViasMinSize ),
                                    internal_units,
                                    true );
     msg.Printf( _( "Minimum value for microvias diameter: <b>%s</b><br>\n" ), GetChars( value ) );
@@ -291,21 +294,35 @@ void DIALOG_DESIGN_RULES::InitGlobalRules()
     AddUnitSymbol( *m_TrackMinWidthTitle );
 
     int Internal_Unit = m_Parent->m_InternalUnits;
-    PutValueInLocalUnits( *m_SetViasMinSizeCtrl, m_BrdSettings->m_ViasMinSize, Internal_Unit );
+#ifdef KICAD_NANOMETRE
+    LengthToTextCtrl( *m_SetViasMinSizeCtrl, m_BrdSettings->m_ViasMinSize );
+    LengthToTextCtrl( *m_SetViasMinDrillCtrl, m_BrdSettings->m_ViasMinDrill );
+#else
+    PutValueInLocalUnits( *m_SetViasMinSizeCtrl,
+                          m_BrdSettings->m_ViasMinSize,
+                          Internal_Unit );
     PutValueInLocalUnits( *m_SetViasMinDrillCtrl, m_BrdSettings->m_ViasMinDrill, Internal_Unit );
+#endif
 
     if(  m_BrdSettings->m_CurrentViaType != VIA_THROUGH )
         m_OptViaType->SetSelection( 1 );
 
     m_AllowMicroViaCtrl->SetSelection(  m_BrdSettings->m_MicroViasAllowed ? 1 : 0 );
+#ifdef KICAD_NANOMETRE
+    LengthToTextCtrl( *m_SetMicroViasMinSizeCtrl, m_BrdSettings->m_MicroViasMinSize );
+    LengthToTextCtrl( *m_SetMicroViasMinDrillCtrl, m_BrdSettings->m_MicroViasMinDrill );
+    LengthToTextCtrl( *m_SetTrackMinWidthCtrl, m_BrdSettings->m_TrackMinWidth );
+#else
     PutValueInLocalUnits( *m_SetMicroViasMinSizeCtrl,
                           m_BrdSettings->m_MicroViasMinSize,
                           Internal_Unit );
     PutValueInLocalUnits( *m_SetMicroViasMinDrillCtrl,
-                          m_BrdSettings->m_MicroViasMinDrill,
+                          TO_LEGACY_LU( m_BrdSettings->m_MicroViasMinDrill ),
                           Internal_Unit );
-
-    PutValueInLocalUnits( *m_SetTrackMinWidthCtrl, m_BrdSettings->m_TrackMinWidth, Internal_Unit );
+    PutValueInLocalUnits( *m_SetTrackMinWidthCtrl,
+                          m_BrdSettings->m_TrackMinWidth,
+                          Internal_Unit );
+#endif
 
     // Initialize Vias and Tracks sizes lists.
     // note we display only extra values, never the current netclass value.
@@ -609,23 +626,40 @@ void DIALOG_DESIGN_RULES::CopyGlobalRulesToBoard()
     if( m_OptViaType->GetSelection() > 0 )
         m_BrdSettings->m_CurrentViaType = VIA_BLIND_BURIED;
 
+    m_BrdSettings->m_MicroViasAllowed = m_AllowMicroViaCtrl->GetSelection() == 1;
+
+#ifdef KICAD_NANOMETRE
+    // Update vias minimum values for DRC
+    m_BrdSettings->m_ViasMinSize =
+        LengthFromTextCtrl( *m_SetViasMinSizeCtrl );
+    m_BrdSettings->m_ViasMinDrill =
+        LengthFromTextCtrl( *m_SetViasMinDrillCtrl );
+
+    // Update microvias minimum values for DRC
+    m_BrdSettings->m_MicroViasMinSize =
+        LengthFromTextCtrl( *m_SetMicroViasMinSizeCtrl );
+    m_BrdSettings->m_MicroViasMinDrill =
+        LengthFromTextCtrl( *m_SetMicroViasMinDrillCtrl );
+
+    // Update tracks minimum values for DRC
+    m_BrdSettings->m_TrackMinWidth =
+        LengthFromTextCtrl( *m_SetTrackMinWidthCtrl );
+#else
     // Update vias minimum values for DRC
     m_BrdSettings->m_ViasMinSize =
         ReturnValueFromTextCtrl( *m_SetViasMinSizeCtrl, m_Parent->m_InternalUnits );
     m_BrdSettings->m_ViasMinDrill =
         ReturnValueFromTextCtrl( *m_SetViasMinDrillCtrl, m_Parent->m_InternalUnits );
 
-    m_BrdSettings->m_MicroViasAllowed = m_AllowMicroViaCtrl->GetSelection() == 1;
-
     // Update microvias minimum values for DRC
     m_BrdSettings->m_MicroViasMinSize =
         ReturnValueFromTextCtrl( *m_SetMicroViasMinSizeCtrl, m_Parent->m_InternalUnits );
     m_BrdSettings->m_MicroViasMinDrill =
         ReturnValueFromTextCtrl( *m_SetMicroViasMinDrillCtrl, m_Parent->m_InternalUnits );
-
     // Update tracks minimum values for DRC
     m_BrdSettings->m_TrackMinWidth =
         ReturnValueFromTextCtrl( *m_SetTrackMinWidthCtrl, m_Parent->m_InternalUnits );
+#endif
 }
 
 
diff --git a/pcbnew/dialogs/dialog_design_rules_base.cpp b/pcbnew/dialogs/dialog_design_rules_base.cpp
index 94350bf42a..2f275d59dd 100644
--- a/pcbnew/dialogs/dialog_design_rules_base.cpp
+++ b/pcbnew/dialogs/dialog_design_rules_base.cpp
@@ -213,7 +213,6 @@ DIALOG_DESIGN_RULES_BASE::DIALOG_DESIGN_RULES_BASE( wxWindow* parent, wxWindowID
 	fgMinValuesSizer->Add( m_MicroViaMinSizeTitle, 0, wxALIGN_RIGHT|wxALIGN_CENTER_VERTICAL|wxTOP|wxLEFT, 5 );
 	
 	m_SetMicroViasMinSizeCtrl = new wxTextCtrl( m_panelGolbalDesignRules, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, 0 );
-	m_SetMicroViasMinSizeCtrl->SetMaxLength( 6 ); 
 	fgMinValuesSizer->Add( m_SetMicroViasMinSizeCtrl, 0, wxEXPAND|wxTOP|wxRIGHT|wxLEFT, 5 );
 	
 	m_MicroViaMinDrillTitle = new wxStaticText( m_panelGolbalDesignRules, wxID_ANY, _("Min uvia drill dia"), wxDefaultPosition, wxDefaultSize, 0 );
@@ -221,7 +220,6 @@ DIALOG_DESIGN_RULES_BASE::DIALOG_DESIGN_RULES_BASE( wxWindow* parent, wxWindowID
 	fgMinValuesSizer->Add( m_MicroViaMinDrillTitle, 0, wxALIGN_RIGHT|wxTOP|wxBOTTOM|wxLEFT, 5 );
 	
 	m_SetMicroViasMinDrillCtrl = new wxTextCtrl( m_panelGolbalDesignRules, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, 0 );
-	m_SetMicroViasMinDrillCtrl->SetMaxLength( 6 ); 
 	fgMinValuesSizer->Add( m_SetMicroViasMinDrillCtrl, 0, wxEXPAND|wxALL, 5 );
 	
 	sbMinSizesSizer->Add( fgMinValuesSizer, 0, wxEXPAND, 5 );
diff --git a/pcbnew/dialogs/dialog_drc.cpp b/pcbnew/dialogs/dialog_drc.cpp
index a461fa4400..3126730b5c 100644
--- a/pcbnew/dialogs/dialog_drc.cpp
+++ b/pcbnew/dialogs/dialog_drc.cpp
@@ -130,12 +130,21 @@ void DIALOG_DRC_CONTROL::InitValues()
 */
 void DIALOG_DRC_CONTROL::SetDrcParmeters( )
 {
-     m_BrdSettings->m_TrackMinWidth =
+#ifdef KICAD_NANOMETRE
+    m_BrdSettings->m_TrackMinWidth =
+        LengthFromTextCtrl( *m_SetTrackMinWidthCtrl );
+    m_BrdSettings->m_ViasMinSize =
+        LengthFromTextCtrl( *m_SetViaMinSizeCtrl );
+    m_BrdSettings->m_MicroViasMinSize =
+        LengthFromTextCtrl( *m_SetMicroViakMinSizeCtrl );
+#else
+    m_BrdSettings->m_TrackMinWidth =
         ReturnValueFromTextCtrl( *m_SetTrackMinWidthCtrl, m_Parent->m_InternalUnits );
-     m_BrdSettings->m_ViasMinSize =
+    m_BrdSettings->m_ViasMinSize =
         ReturnValueFromTextCtrl( *m_SetViaMinSizeCtrl, m_Parent->m_InternalUnits );
-     m_BrdSettings->m_MicroViasMinSize =
+    m_BrdSettings->m_MicroViasMinSize =
         ReturnValueFromTextCtrl( *m_SetMicroViakMinSizeCtrl, m_Parent->m_InternalUnits );
+#endif
 }
 
 
diff --git a/pcbnew/drc.cpp b/pcbnew/drc.cpp
index 3f45f74e62..53f932a3cd 100644
--- a/pcbnew/drc.cpp
+++ b/pcbnew/drc.cpp
@@ -54,15 +54,24 @@ void DRC::ShowDialog()
 
         // copy data retained in this DRC object into the m_ui DrcPanel:
 
+#ifdef KICAD_NANOMETRE
+        LengthToTextCtrl( *m_ui->m_SetTrackMinWidthCtrl,
+                          m_pcb->GetBoardDesignSettings()->m_TrackMinWidth );
+        LengthToTextCtrl( *m_ui->m_SetViaMinSizeCtrl,
+                          m_pcb->GetBoardDesignSettings()->m_ViasMinSize );
+        LengthToTextCtrl( *m_ui->m_SetMicroViakMinSizeCtrl,
+                          m_pcb->GetBoardDesignSettings()->m_MicroViasMinSize );
+#else
         PutValueInLocalUnits( *m_ui->m_SetTrackMinWidthCtrl,
-                              m_pcb->GetBoardDesignSettings()->m_TrackMinWidth,
+                              TO_LEGACY_LU( m_pcb->GetBoardDesignSettings()->m_TrackMinWidth ),
                               m_mainWindow->m_InternalUnits );
         PutValueInLocalUnits( *m_ui->m_SetViaMinSizeCtrl,
-                              m_pcb->GetBoardDesignSettings()->m_ViasMinSize,
+                              TO_LEGACY_LU( m_pcb->GetBoardDesignSettings()->m_ViasMinSize ),
                               m_mainWindow->m_InternalUnits );
         PutValueInLocalUnits( *m_ui->m_SetMicroViakMinSizeCtrl,
-                              m_pcb->GetBoardDesignSettings()->m_MicroViasMinSize,
+                              TO_LEGACY_LU( m_pcb->GetBoardDesignSettings()->m_MicroViasMinSize ),
                               m_mainWindow->m_InternalUnits );
+#endif
 
         m_ui->m_CreateRptCtrl->SetValue( m_doCreateRptFile );
         m_ui->m_RptFilenameCtrl->SetValue( m_rptFilename );
@@ -313,12 +322,12 @@ bool DRC::doNetClass( NETCLASS* nc, wxString& msg )
     }
 #endif
 
-    if( nc->GetTrackWidth() < g.m_TrackMinWidth )
+    if( nc->GetTrackWidth() < TO_LEGACY_LU( g.m_TrackMinWidth ) )
     {
         msg.Printf( _( "NETCLASS: '%s' has TrackWidth:%s which is less than global:%s" ),
                     GetChars( nc->GetName() ),
                     FmtVal( nc->GetTrackWidth() ),
-                    FmtVal( g.m_TrackMinWidth )
+                    FmtVal( TO_LEGACY_LU( g.m_TrackMinWidth ) )
                     );
 
         m_currentMarker = fillMarker( DRCE_NETCLASS_TRACKWIDTH, msg, m_currentMarker );
@@ -327,12 +336,12 @@ bool DRC::doNetClass( NETCLASS* nc, wxString& msg )
         ret = false;
     }
 
-    if( nc->GetViaDiameter() < g.m_ViasMinSize )
+    if( nc->GetViaDiameter() < TO_LEGACY_LU( g.m_ViasMinSize ) )
     {
         msg.Printf( _( "NETCLASS: '%s' has Via Dia:%s which is less than global:%s" ),
                     GetChars( nc->GetName() ),
                     FmtVal( nc->GetViaDiameter() ),
-                    FmtVal( g.m_ViasMinSize )
+                    FmtVal( TO_LEGACY_LU( g.m_ViasMinSize ) )
                     );
 
         m_currentMarker = fillMarker( DRCE_NETCLASS_VIASIZE, msg, m_currentMarker );
@@ -341,12 +350,12 @@ bool DRC::doNetClass( NETCLASS* nc, wxString& msg )
         ret = false;
     }
 
-    if( nc->GetViaDrill() < g.m_ViasMinDrill )
+    if( nc->GetViaDrill() < TO_LEGACY_LU( g.m_ViasMinDrill ) )
     {
         msg.Printf( _( "NETCLASS: '%s' has Via Drill:%s which is less than global:%s" ),
                     GetChars( nc->GetName() ),
                     FmtVal( nc->GetViaDrill() ),
-                    FmtVal( g.m_ViasMinDrill )
+                    FmtVal( TO_LEGACY_LU( g.m_ViasMinDrill ) )
                     );
 
         m_currentMarker = fillMarker( DRCE_NETCLASS_VIADRILLSIZE, msg, m_currentMarker );
@@ -355,12 +364,12 @@ bool DRC::doNetClass( NETCLASS* nc, wxString& msg )
         ret = false;
     }
 
-    if( nc->GetuViaDiameter() < g.m_MicroViasMinSize )
+    if( nc->GetuViaDiameter() < TO_LEGACY_LU( g.m_MicroViasMinSize ) )
     {
         msg.Printf( _( "NETCLASS: '%s' has uVia Dia:%s which is less than global:%s" ),
                     GetChars( nc->GetName() ),
                     FmtVal( nc->GetuViaDiameter() ),
-                    FmtVal( g.m_MicroViasMinSize )
+                    FmtVal( TO_LEGACY_LU( g.m_MicroViasMinSize ) )
                     );
 
         m_currentMarker = fillMarker( DRCE_NETCLASS_uVIASIZE, msg, m_currentMarker );
@@ -369,12 +378,12 @@ bool DRC::doNetClass( NETCLASS* nc, wxString& msg )
         ret = false;
     }
 
-    if( nc->GetuViaDrill() < g.m_MicroViasMinDrill )
+    if( nc->GetuViaDrill() < TO_LEGACY_LU( g.m_MicroViasMinDrill ) )
     {
         msg.Printf( _( "NETCLASS: '%s' has uVia Drill:%s which is less than global:%s" ),
                     GetChars( nc->GetName() ),
                     FmtVal( nc->GetuViaDrill() ),
-                    FmtVal( g.m_MicroViasMinDrill )
+                    FmtVal( TO_LEGACY_LU( g.m_MicroViasMinDrill ) )
                     );
 
         m_currentMarker = fillMarker( DRCE_NETCLASS_uVIADRILLSIZE, msg, m_currentMarker );
diff --git a/pcbnew/ioascii.cpp b/pcbnew/ioascii.cpp
index 7d90c55537..e67f84e97c 100644
--- a/pcbnew/ioascii.cpp
+++ b/pcbnew/ioascii.cpp
@@ -449,7 +449,8 @@ int PCB_BASE_FRAME::ReadSetup( LINE_READER* aReader )
 
         if( stricmp( line, "TrackMinWidth" ) == 0 )
         {
-            GetBoard()->GetBoardDesignSettings()->m_TrackMinWidth = atoi( data );
+            double width = atof( data );
+            GetBoard()->GetBoardDesignSettings()->m_TrackMinWidth = FROM_LEGACY_LU( width );
             continue;
         }
 
@@ -478,7 +479,8 @@ int PCB_BASE_FRAME::ReadSetup( LINE_READER* aReader )
 
         if( stricmp( line, "ViaMinSize" ) == 0 )
         {
-            GetBoard()->GetBoardDesignSettings()->m_ViasMinSize = atoi( data );
+            double diameter = atof( data );
+            GetBoard()->GetBoardDesignSettings()->m_ViasMinSize = FROM_LEGACY_LU( diameter );
             continue;
         }
 
@@ -489,7 +491,8 @@ int PCB_BASE_FRAME::ReadSetup( LINE_READER* aReader )
 
         if( stricmp( line, "MicroViaMinSize" ) == 0 )
         {
-            GetBoard()->GetBoardDesignSettings()->m_MicroViasMinSize = atoi( data );
+            double diameter = atof( data );
+            GetBoard()->GetBoardDesignSettings()->m_MicroViasMinSize = FROM_LEGACY_LU( diameter );
             continue;
         }
 
@@ -519,7 +522,8 @@ int PCB_BASE_FRAME::ReadSetup( LINE_READER* aReader )
 
         if( stricmp( line, "ViaMinDrill" ) == 0 )
         {
-            GetBoard()->GetBoardDesignSettings()->m_ViasMinDrill = atoi( data );
+            double diameter = atof( data );
+            GetBoard()->GetBoardDesignSettings()->m_ViasMinDrill = FROM_LEGACY_LU( diameter );
             continue;
         }
 
@@ -532,8 +536,8 @@ int PCB_BASE_FRAME::ReadSetup( LINE_READER* aReader )
 
         if( stricmp( line, "MicroViaMinDrill" ) == 0 )
         {
-            int diameter = atoi( data );
-            GetBoard()->GetBoardDesignSettings()->m_MicroViasMinDrill = diameter;
+            double diameter = atof( data );
+            GetBoard()->GetBoardDesignSettings()->m_MicroViasMinDrill = FROM_LEGACY_LU( diameter );
             continue;
         }
 
@@ -694,7 +698,9 @@ static int WriteSetup( FILE* aFile, PCB_EDIT_FRAME* aFrame, BOARD* aBoard )
 
     fprintf( aFile, "TrackClearence %d\n", netclass_default->GetClearance() );
     fprintf( aFile, "ZoneClearence %d\n", g_Zone_Default_Setting.m_ZoneClearance );
-    fprintf( aFile, "TrackMinWidth %d\n", aBoard->GetBoardDesignSettings()->m_TrackMinWidth );
+    fprintf( aFile,
+             "TrackMinWidth %f\n",
+             TO_LEGACY_LU_DBL( aBoard->GetBoardDesignSettings()->m_TrackMinWidth ) );
 
     fprintf( aFile, "DrawSegmWidth %d\n", aBoard->GetBoardDesignSettings()->m_DrawSegmentWidth );
     fprintf( aFile, "EdgeSegmWidth %d\n", aBoard->GetBoardDesignSettings()->m_EdgeSegmentWidth );
@@ -702,8 +708,12 @@ static int WriteSetup( FILE* aFile, PCB_EDIT_FRAME* aFrame, BOARD* aBoard )
     // Save current default via size, for compatibility with older Pcbnew version;
     fprintf( aFile, "ViaSize %d\n", netclass_default->GetViaDiameter() );
     fprintf( aFile, "ViaDrill %d\n", netclass_default->GetViaDrill() );
-    fprintf( aFile, "ViaMinSize %d\n", aBoard->GetBoardDesignSettings()->m_ViasMinSize );
-    fprintf( aFile, "ViaMinDrill %d\n", aBoard->GetBoardDesignSettings()->m_ViasMinDrill );
+    fprintf( aFile,
+             "ViaMinSize %f\n",
+             TO_LEGACY_LU_DBL( aBoard->GetBoardDesignSettings()->m_ViasMinSize ) );
+    fprintf( aFile,
+             "ViaMinDrill %f\n",
+             TO_LEGACY_LU_DBL( aBoard->GetBoardDesignSettings()->m_ViasMinDrill ) );
 
     // Save custom vias diameters list (the first is not saved here: this is
     // the netclass value
@@ -719,11 +729,11 @@ static int WriteSetup( FILE* aFile, PCB_EDIT_FRAME* aFrame, BOARD* aBoard )
              "MicroViasAllowed %d\n",
              aBoard->GetBoardDesignSettings()->m_MicroViasAllowed );
     fprintf( aFile,
-             "MicroViaMinSize %d\n",
-             aBoard->GetBoardDesignSettings()->m_MicroViasMinSize );
+             "MicroViaMinSize %f\n",
+             TO_LEGACY_LU_DBL( aBoard->GetBoardDesignSettings()->m_MicroViasMinSize ) );
     fprintf( aFile,
-             "MicroViaMinDrill %d\n",
-             aBoard->GetBoardDesignSettings()->m_MicroViasMinDrill );
+             "MicroViaMinDrill %f\n",
+             TO_LEGACY_LU_DBL( aBoard->GetBoardDesignSettings()->m_MicroViasMinDrill ) );
 
     fprintf( aFile, "TextPcbWidth %d\n", aBoard->GetBoardDesignSettings()->m_PcbTextWidth );
     fprintf( aFile,