Tapes are created with the IDL procedure MKTAP. A blank 8mm tape should be in the desired tape drive before one starts the procedure. The nominal mode starting this procedure is to specify the device as a parameter: IDL> mktap, dev where, dev can be either a string-type variable such as `/dev/nrmt0h' or an integer 0, 1, 2, etc., which specifies the device number. The procedure can also be started with out a device specified. However, in this case the program assume the tape is in one of the follow defaults devices (system dependent): `/dev/nrmt0h' for Ultrix systems, `/dev/rmt/tps0d6nrnsv' for IRIX systems, and `/dev/nrst0' for SUN systems. The first question one must answer is the name of the data directory (note this is NOT the path). For example, if the path to the archive data is `/yd4/92_12a' then the data directory is `92_12a'. The second and typically last question asks whether to archive all files or part of the files within the data directory. After answering this final question a script file called `mktape.com' and two tape directory files xbdyy_wka.xx (binary version) and xadyy_wka.xx (ascii version) are created in the data directory. It is important to note that the file ID of the tape directory files (xad and xbd) is the same as the name of the tape which will hold these files. This completes the IDL procedure MKTAP. To make the tape one types the following command: % source mktap.comMKTAP also has a number of switches which can be specified with the MKTAP command to allow the program to run in different modes. Listed below are a few examples, see the program header to MKTAP for a complete list: IDL> mktap, 1, datadir='91_50a,91_51a'will use tape drive `/dev/nrmt1h' on Ultrix systems, and archive weekly files from sub-directory `91_50a' and all requested reformatted data from both sub-directories. IDL> mktap, 1, datadir='91_50a,91_51a', /alldatasame as above command, except that there will be no prompt for which reformatted files to place on the tape as all reformatted data from both directories will be archived.
As final comment there are a number of constraints one should be aware of when creating archive tapes. First, one must have WRITE privilege to the data directory. This is necessary since MKTAP creates a script file and two versions of the tape directory files in the data directory. Secondly, an observing log with the name which corresponds to the dates of the data archived must be on the directory or the program will prompt the user for its name.