HP PCL/PJL reference - Printer Job Language Technical Reference Manual

A-46 Product-Specific Feature Support EN
Commands That Affect Printer Memory
Four conditions may cause the printer to reconfigure user memory:
When the printer language changes, either implicitly or
explicitly by using the ENTER LANGUAGE command (except
when resource saving is enabled).
When the page protection setting changes, using the SET or
DEFAULT commands, or when the printer is reset using the
RESET or INITIALIZE commands or by using the control
panel.
When the resolution is changed using either the SET or
DEFAULT commands, or by using the control panel.
When changing the I/O buffering or resource saving settings.
Reconfiguring printer memory erases all volatile personality-specific
resource information, including downloaded fonts, PCL macros, and
PostScript dictionaries (however no I/O data is lost). Memory can be
reconfigured only when these conditions actually change the page
protection, resolution, or printer language status. For example, if the
resolution is at 600 dpi and an application sends the @PJL SET
RESOLUTION = 600 command, memory is not reconfigured.
If resource saving is enabled, memory is reconfigured, but all volatile
personality-specific resource information (such as fonts, macros, and
PostScript dictionaries) are not lost (see “Resource Saving” below). If
resource saving is disabled, these resources are erased.
Printers that reconfigure memory due to PJL commands:
HP LaserJet 4, 4M, 4 Plus, 4M Plus, 4V, 4MV, 4Si, 4SiMx, 4ML,
4P, 4MP, 4PJ, 4LJ Pro, 4LC, 4000 series, 5, 5M, 5P, 5MP, 6L,
6P, 6MP, 5Si, 5SiMx, 5Si Mopier, HP Color LaserJet, HP Color
LaserJet 5, 5M, LaserJet 1100 series, 2100 series, 4500
series, 5000 series, 8000 series, 8100 series, 8500 series