login.tsp is a special INPUT file; it is read automatically at the start of interactive sessions and batch jobs. This is useful for setting default options for a run.
If you use the same options repeatedly, you may want to place them in a login.tsp file. Every time TSP starts, it checks for a login.tsp file, and executes it first. Normally, TSP looks for login.tsp in your working directory. If it does not find one, it looks in the directory in which you installed TSP for DOS and Windows, in the folder in which you installed TSP for Macs, and in the home directory on Unix.
Commands which can be usefully issued in a login.tsp file are the following
OPTIONS MEMORY= approximate memory to be used by TSP (in Megabytes). This option only works if OPTIONS is the first command in the run, or the first command in the login.tsp file.
INPUT some file that transforms the data or selects the data you are using for a number of TSP programs.