Hi Ibrahim! > I also found another package NAMOT (from Bill's website, thanks Bill); I > managed to install the package on MacOs PPC using fink. > > However, I have a problem to run the program: issuing "namot" on the > command line starts the program for a second (flashing the Gui of Namot) and > > returns the error: Creating shared mem segment: Cannot allocate memory > 2800*700=1960000 > I am sorry I missed this the first time around; I've been sucked into the vortex of interminable intro chem teaching... I've seen this bug a number of times and have filed a bug report. It is hard to reproduce, but if you reboot it works. There is a real cockroach of a bug that is harder to fix, however -- it messes up the phosphate linkages between G and U I think. I haven't however touched that program since Paul put an RNA builder in Coot. If you have coot, go to Calculate > Other Modelling Tools > Ideal DNA/RNA and you can generate an A-form helix or a single strand of RNA, and then manipulate it to your heart's content. I hope that helps. Bill