Protected Mode Access Checks

protectedmode2.cs

class Selector
{
    public byte[] memory;
    bool writable;
}

Selector[] _selectorTable;

public void WriteByte(ushort seg, ushort offset, byte value)
{
    try
    {
        var sel = _selectorTable[seg >> 3];
        if (!sel.writable)
            throw new Sharp86.GeneralProtectionFaultException();
        sel.memory[offset] = value;
    }
    catch (NullReferenceException)
    {
        throw new Sharp86.SegmentNotPresentException();
    }
    catch (IndexOutOfRangeException)
    {
        throw new Sharp86.GeneralProtectionFaultException();
    }

}