Runs prepared for GP01 plots (with a large number of calculated intervals) or with several VARY records or ALTER phases can produce copious quantities of output directed to the ASCII output file. To avoid running out of disk space, direct the ASCII output file to the printer (have lots of paper in place!), the console (CON), or the null (NUL) device. The analysis will run fastest with output directed to the null device. The compressed data will be saved to disk if there is a FILE record in the run or if any PLOTs are requested. Plots can then be obtained using plot only runs (see below) to access the compressed data files.
Another method of reducing the size of ASCII output files is to use the NTAB option on the OPTions record. This option will print out the tabular data heading but will suppress the printing of the data itself. The tabular data heading can be used to document what variables are available in the compressed data files.