Hi, I've defined the following user classes in my project settings. HDATA(0x700000-0x77FFFF), EDATA(0x7F0000-0x7F04FF), ECODE (0x800000-0xFFFFFE), HCONST (0x800000-0xFFFFFE) When I compile my program, I get the following cmpilation error: error C249: 'FDATA': SEGMENT TOO LARGE I thought that the FDATA class was meant for the C166 device!! Please let me know what I can do to avoid/solve this problem. -Sundeep