Windows Print Spool Files
Windows Print spool files will have PCL data in them when the print
data they contain is intended for an HP LaserJet printer. Therefore,
spool files can be used with JetPCL. Spool files are normally the
*.SPL files found in the "C:\Windows\system32\spool\printers" folder
along with a *.SHD file (this is the associated schedule file).
However, normally these spool files are deleted as soon as the print
job is finshed.