Data scans are stored on the disk of the ModComp known as the T file. The data can be recalled by scan number in the range 1000-30000. The T file is a circular data structure such that the oldest scan is removed prior to writing the most recently observed scan. The length of time a given scan remains within the T file depends upon the size of an observer's data and how it is collected. Typically, it takes several weeks for the data to wrap around. However, an observer can not depend on the uniformity of this cycle and should routinely transfer the data to the UNIX workstation every several hours or more frequently. Since the 1998-1999 observing seasons, all data taken by the telescope is archived and can be retrieved from a set of CDs. In the rare circumstance where the user must alter the data storage scan number, typing SCAN (number) will change the number of the next scan to be stored.
Be sure to check after using this keyword that you have not made a mistake that might cause someone else's data to be written over
To speed up data storage on the disk, the user may enter the keyword BRIEF. This causes subsequent scans to be stored only in the 1000 scan T file. This option remains in effect until the user next types FULL , after which the T1 and T2 calculations are also stored on disk. The normal operation is to store data in BRIEF mode.
Observers may insert messages into the stored data scan header through the following keywords: