Hi, I've been using the PSR f90 compiler on my home machine and am very happy with it. However, what I can't figure/find out from the documentation (including the g77 stuff) is if there's a command line switch which promotes all single precision variables (and constants) to double precision. Does anyone know off the top of their head? Thanks Sean -------------------- Dr Sean Oughton, Lecturer, Mathematics, University College London Gower St, London WC1E 6BT, UK. www.ucl.ac.uk/~ucahsea/oughton.html Fax: +44 (020) 7383-5519. Phone: +44 (020) 7679-2218. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%