Mike Carr, Richard Lucinio, Charles Corson and myself solved a long-standing DIS problem two weeks ago. The problem was that the "dis home" MC command leaves the detent retracted, so the turret is not locked in place. This produces random errors in the low-res spectra, since the low-res position is the home position. The problem existed due to a code change made several years ago in the Mirella code on the DIS PC, in which an extra command was added to home the detent after the turret was homed. This "DHOME" command retracts the turret. I deleted the command from the source file, with the result that the detent now functions properly. We also checked the mechanical integrity of the turret wheel assembly. No mechanical problems were found. We have performed several tests of the turret registration (take a spectra, change the configuration, return to the original configuration and take another spectra) in the past two weeks. We see variations on the order of one pixel, which while not optimal, are much better than previously reported. Jon Brinkmann APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 37 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