I've run into a problem opening a very large 2D array (~82000x88000) in IDL 7.1. I've run my code on both a PC and a Mac, each with 12 GB or more RAM, and I get the same error. If I use exactly the same code but try to load an array that is (say) 41000x48000 IDL does just fine. The line on which the fatal error occurs is the following: chan_mask=read_binary(rundata.f0,DATA_DIMS=[81966L,87579L],DATA_TYPE=1) Is this a known bug in IDL 7.1? If so, is the problem fixed in IDL 8.1? If not, is there some other good way for me to read in this image that won't be painfully slow? Thanks in advance. . . . Tamlin