The printer has two dual in-line memory module (DIMM) slots
for upgrading with:
More printer memory. DIMMs are available in 16, 32, and 64 MB,
for a maximum of 192 MB.
Flash memory DIMMs, available in 2 and 4 MB. Unlike standard
printer memory, flash DIMMs can be used to permanently store
downloaded items in the printer, even when the printer is off.
DIMM-based accessory fonts, macros, and patterns.
Other DIMM-based printer languages and printer options.
Single in-line memory modules (SIMMs) used on previous
HP LaserJet printers are not compatible with the printer.
You might want to add more memory to the printer if you often print
complex graphics, use many downloaded fonts, print at ProRes
1200, or print large paper sizes (such as A3, B4, or 11 x 17).
To find out how much memory is installed in the printer, print a
configuration page (page 80).
Printer Memory and Expansion