To start the longslit pipeline, from an IDL prompt type:

IDL> firehose_ld

where the _ld stands for low-dispersion.  This should bring up the following window: 

The first step is to enter in exposure file names for each of the fields listed.  The Raw and Reduction directories may be set to any location on disk where you want these files to reside.  FIREHOSE never over-writes raw data, but we advise against performing reductions in the raw data directory as a precaution.

The OBJECT file denotes a science frame.  The software performs sky subtraction on a fram-by-frame basis, NOT with A-B-B-A sets.  Only one file at a time is handled although we will loop on these in the next release.