- HP All-in-One Printer Manual

Q2431-90912 Chapter 5 Theory of operation 129
Printer memory
If the printer encounters difficulty managing available memory, a clearable warning message
appears on the control panel.
Some printer messages are affected by the auto-continue and clearable warning settings from
the configuration menu on the printer control panel. If CLEARABLE WARNING=JOB is set on the
control panel, warning messages appear on the control panel until the end of the job from which
they were generated. If CLEARABLE WARNING=ON is set, warning messages appear on the control
panel until G
O is pressed. If an error occurs that prevents printing and AUTO CONTINUE=ON is set,
the printer goes offline for 10 seconds before it returns online. If AUTO CONTINUE=OFF is set, the
message appears until G
O is pressed.
Read-only memory
Besides storing microprocessor control programs, the read-only memory (ROM) stores dot
patterns of internal character sets (fonts).
Random-access memory
The random-access memory (RAM) contains the page, I/O buffers, and the font storage area. It
stores printing and font information received from the host system, and can also serve to
temporarily store a full page of print-image data before the data is sent to the print engine.
Memory capacity can be increased by adding DIMMs to the formatter. Note that adding memory
(DIMMs) might also increase the print speed for complex graphics.
DIMM slots
The DIMM slots can be used to add memory, fonts, or firmware upgrades.
Firmware DIMM
To upgrade printer firmware, insert a new firmware DIMM in DIMM slot 1 (the uppermost slot)
inside the formatter assembly. See “Firmware DIMM” on page 160.
CAUTION The firmware DIMM must be installed in slot 1 (formatter PCA location J1; top-most slot)
Nonvolatile memory
The printer uses nonvolatile memory (NVRAM) to store I/O and information about the print
environment’s configuration. The contents of NVRAM are retained when the printer is turned off
or disconnected.
Memory Enhancement technology
The HP Memory Enhancement technology (MEt) effectively doubles the standard memory
through a variety of font- and data-compression methods.
Note The MEt is only available in PCL mode; it is not functional when printing in PS mode.