Hi there, I have generated a huge data file (approx 500MB large) containing a few 100k lines of formatted data (format(1X, 200ES11.4)). As I believe handling such a large file might over and over again (will be opened by an explicit FE code) might slow down the process significantely, I was thinking to split this file into many smaller files that contain certain columns of data (eg. file element1.txt contains columns 1 and 2, element2.txt contains columns 1 and 3, element3.txt contains columns 1 and 4.....element150.txt contains columns 1 and 151) and call those when I need them (I only need a few data points during the calculations). I managed to create those files, but I am struggeling to pass the correct data to those files. Pointers might be good, but I do not know if and how they work with fortran 77. Is there a simple way of doing this? Thanks a lot.