Function unicode_2_utf8(x As Long) As String
    Dim As String y
    Dim As Long r
    Select Case x
    Case 0 To &H7F
        y = Chr(x)
    Case &H80 To &H7FF
        y = Chr(192 + x \ 64) + Chr(128 + x Mod 64)
    Case &H800 To &H7FFF, 32768 To 65535
        r = x \ 64
        y = Chr(224 + r \ 64) + Chr(128 + r Mod 64) + Chr(128 + x Mod 64)
    Case &H10000 To &H10FFFF
        r = x \ 4096
        y = Chr(240 + r \ 64) + Chr(128 + r Mod 64) + Chr(128 + (x \ 64) Mod 64) + Chr(128 + x Mod 64)
    Case Else
        Print "what else? " & x & " " & Hex(x)
    End Select
    Return y
End Function

Function utf8_2_unicode(x As String) As Long
    Dim As Long primero, segundo, tercero, cuarto
    Dim As Long total
    Select Case Len(x)
    Case 1 'one byte
        If Asc(x) < 128 Then
            total = Asc(x)
        Else
            Print "highest bit set error"
        End If
    Case 2 'two bytes and assume primero byte is leading byte
        If Asc(x) \ 32 = 6 Then
            primero = Asc(x) Mod 32
            If Asc(Mid(x, 2, 1)) \ 64 = 2 Then
                segundo = Asc(Mid(x, 2, 1)) Mod 64
            Else
                Print "mask error"
            End If
        Else
            Print "leading byte error"
        End If
        total = 64 * primero + segundo
    Case 3 'three bytes and assume primero byte is leading byte
        If Asc(x) \ 16 = 14 Then
            primero = Asc(x) Mod 16
            If Asc(Mid(x, 2, 1)) \ 64 = 2 Then
                segundo = Asc(Mid(x, 2, 1)) Mod 64
                If Asc(Mid(x, 3, 1)) \ 64 = 2 Then
                    tercero = Asc(Mid(x, 3, 1)) Mod 64
                Else
                    Print "mask error last byte"
                End If
            Else
                Print "mask error middle byte"
            End If
        Else
            Print "leading byte error"
        End If
        total = 4096 * primero + 64 * segundo + tercero
    Case 4 'four bytes and assume primero byte is leading byte
        If Asc(x) \ 8 = 30 Then
            primero = Asc(x) Mod 8
            If Asc(Mid(x, 2, 1)) \ 64 = 2 Then
                segundo = Asc(Mid(x, 2, 1)) Mod 64
                If Asc(Mid(x, 3, 1)) \ 64 = 2 Then
                    tercero = Asc(Mid(x, 3, 1)) Mod 64
                    If Asc(Mid(x, 4, 1)) \ 64 = 2 Then
                        cuarto = Asc(Mid(x, 4, 1)) Mod 64
                    Else
                        Print "mask error last byte"
                    End If
                Else
                    Print "mask error tercero byte"
                End If
            Else
                Print "mask error second byte"
            End If
        Else
            Print "mask error leading byte"
        End If
        total = Clng(262144 * primero + 4096 * segundo + 64 * tercero + cuarto)
    Case Else
        Print "more bytes than expected"
    End Select
    Return total
End Function

Dim As Long cp(4) = {65, 246, 1046, 8364, 119070} '[{&H0041,&H00F6,&H0416,&H20AC,&H1D11E}]
Dim As String r, s
Dim As integer i, j
Print "ch  unicode  UTF-8 encoded  decoded"
For i = Lbound(cp) To Ubound(cp)
    Dim As Long cpi = cp(i)
    r = unicode_2_utf8(cpi)
    s = Hex(cpi)
    Print Chr(cpi); Space(10 - Len(s)); s;
    s = ""
    For j = 1 To Len(r)
        s &= Hex(Asc(Mid(r, j, 1))) & " "
    Next j
    Print Space(16 - Len(s)); s;
    s = Hex(utf8_2_unicode(r))
    Print Space(8 - Len(s)); s
Next i

Sleep