C64Lib.Core.MOS6510.read_emulator_id C# (CSharp) Method

        byte read_emulator_id(UInt16 adr)
        {
            switch (adr)
            {
                case 0x7c:	// $dffc: revision
                    return (byte)(FRODO_REVISION << 4);
                case 0x7d:	// $dffd: version
                    return FRODO_VERSION;
                case 0x7e:	// $dffe returns 'F' (Frodo ID)
                    return (byte)'F';
                case 0x7f:	// $dfff alternates between $55 and $aa
                    dfff_byte = (byte)~dfff_byte;
                    return dfff_byte;
                default:
                    return adr - 0x20 >= frodo_id.Length ? (byte)0x00 : (byte)frodo_id[adr - 0x20];
            }
        }