I've just done a little more work on DIS. The changes are: There's a new command to set the zeropoint of the gratings: dis grating n=? col=? zerostep=? e.g. dis grating n=1 col=b zerostep=123 There's a new zerostep:[BR]{low,med,high}=123 keyword I found and worked around a bug in the TDS firmware that meant that the FILTER1 keyword was always the same. The possible values are now CLEAR and G/R (note that this is a change: it was previously always FILTER0.) All of these, along with the dis grating n=1 type=low command, are only present in my new version of the dis software. I believe that we are currently running the old version --- you can check using the dis status version command. The new version is "Version 1.6 April 1998" R APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 51 in the apo35-dis archive. You can find APO the archive on http://www.astro.princeton.edu/APO/apo35-dis/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-dis@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO