Several improved routines associated with hsi_spectrogram have been = placed in atest. They effect all of the binned data, i.e. spectrum, = lightcurve, and image. An important fix is to a bug introduced into the dropout routine about = June 24. Since that time, the bug caused the DP_CUTOFF parameter to be = ignored. The effect was to create large datagaps and excess apparent = deadtime when the rates were low. This may have also had a marginal = effect on imaging with low total count rates, I can't assess how serious = it might be. This was a very nasty bug, introduced when I fixed another = problem. I need to add to the test suite so we can be certain to catch = these problems sooner. As a caveat, many people run the lightcurve gui = when initally examining an event, or look at the observing summary. = Presently, the standard view of these rates is not corrected for = deadtime. There was also a fix to the NPHT out of range bug in that routine. In hsi_spectrogram__livetime_merge_datagaps.pro there were two fixes: ;Add protection for one sel1 value, ras, 13-aug-02. ;Ensure that ut_off.e is after ut_off.s, ras, 14-aug-02. In hsi_spectrogram__define there are three changes: The control of the binning algorithm has been made more robust. That = should reduce the time to fix future bugs in this area, and hopefully = reduce some of the bizarre results you may have experienced from time to = time. One change affects the counts in the last channel of a spectrum = which should be unimportant for most puposes. The other change = introduces support for adjusting the detector calibration as a function = of time through a file in SPEC_RESP. This should be transparent to = everyone but important for the best quality spectroscopy, particularly = narrow line spectroscopy. =20 The F_DIV function has been changed to be more like the division = operator in IDL. The purpose of F_DIV() is to provide a division = operation which traps division by zero, and sets the result to 0 or a = user default. The version online could result in an array as large as = the denominator array, instead of the lessor size of the numerator and = denominator arrays. If you have been using this function, it may cause = problems if these two arrays could have different sizes, so beware. The changes to the other routines are minor. Richard