HP PCL/PJL reference - Printer Job Language Technical Reference Manual
9-18 PJL File System Commands EN
Example Summary
The FSDOWNLOAD command downloads data to printers which
support this command. This command allows data to be downloaded
to either the printers internal disk (such as available in HP LaserJet
4000 series, 5Si, 5SiMx, and 5Si Mopier printers) or flash memory
(such as available in HP LaserJet 5, 5M, and 4000 series printers).
To identify what is stored on the disk or in flash memory, you can print
a directory listing for that memory device. This directory listing
identifies all directories, file names, and file sizes. A directory listing
can be printed from the printer's control panel by selecting either the
Disk Directory page or the Flash Directory page in the Test menu.
Note A file system command sequence can be typed in a text editor and
copied to the printer, but there are some places where binary data
needs to be sent. This is not a problem as long as there is an ASCII
character equivalent to the necessary decimal value. For example,
the decimal value for Escape is 027. There is an ASCII character (←)
for this decimal value, thus it can be typed in a text editor.
There might be times when a text editor will not allow you to type a
character with a certain decimal value. For example, you might need
to send the character whose decimal value is 000. There is no ASCII
character for that value, thus a text editor will not allow you to send
this byte to the printer.