Hi, There are a few big EIS fits files which are not easy to be processed by "eis_prep", for example: 20/eis_l0_20070820_170353.fits.gz 122M \\ %%collapse More *21/eis_l0_20070821_000022.fits.gz 118M \\ *21/eis_l0_20070821_133226.fits.gz 117M \\ %% 22/eis_l0_20070822_023009.fits.gz 116M \\ 23/eis_l0_20070823_191420.fits.gz 94M \\ 24/eis_l0_20070824_001531.fits.gz 92M \\ 24/eis_l0_20070824_105128.fits.gz 120M \\ 25/eis_l0_20070825_015152.fits.gz 99M \\ 25/eis_l0_20070825_050529.fits.gz 95M \\ 25/eis_l0_20070825_093750.fits.gz 89M \\ 26/eis_l0_20070826_005803.fits.gz 97M \\ 26/eis_l0_20070826_055213.fits.gz 92M \\ 27/eis_l0_20070827_045520.fits.gz 97M \\ 27/eis_l0_20070827_170835.fits.gz 81M \\ 27/eis_l0_20070827_210723.fits.gz 79M \\ 28/eis_l0_20070828_005937.fits.gz 72M \\ These fits files are mostly generated by study "": doing full-ccd scan (often over 80 raster positions). The typical error message is: "unable to allocate memory to make array". However, the machine that running "eis_prep" has fairly big enough memory (4GB). Is there any way to do 'eis_prep' with these big fits files?\\ Or do we need to suggest that normally do not use full-ccd scan with too many raster postions? Regards, JianSun