Hi I can't get fg random to work with pre-compiled 64 bit version: SEISMIC ANALYSIS CODE [08/24/2009 (Version 101.3b)] Copyright 1995 Regents of the University of California SAC> fg random SAC> lh depmin depmax FILE: RANDOM01 - 1 -------------- depmin = -nan depmax = -nan SAC> Has anyone else encountered this? Regards Frederik