This might be of general interest to GRIM II users: During the November shutdown, the known GRIM II exposure times bug (described in http://astro.uchicago.edu/home/web/bjr/GRIM2/Bugs/expTim.html) appears to have taken a somewhat new form. The old form was that actual exposure times were 1.09 sec longer than the requested exposure time. The time recorded in the header was the requested one, not the actual one. Now, the exposure times sent to the MC with "nexpose it=x" are modified to x - 1.09 sec. (So for example, a requested exposure time of 5 sec gives a reported OPENTIME= 3.909000 in the image header.) This brings the actual exposure time in line with the requested one to pretty good accuracy (my crude check of counts/sec from dome flats suggests true times may be OPENTIME + 1.0 rather than OPENTIME + 1.1, but that is chi-by-eye and should not be taken too seriously). The drawback is that a requested exposure time below about 1.2 seconds seems to hang the instrument, requiring a "stop inst" command to be issued to wake it up again. I have only checked this for the Sun mcnode interface, but I suspect it is true for the Mac Remark interface also, since Remark sends stuff to the MC. James Rhoads. APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 3 in the apo35-grim archive. You can find APO the archive on http://astro.princeton.edu:82/apo35-grim/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-grim@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO