HP 2605dtn - Manual (Page 189)

Memory
Product name Description Part number
Memory upgrades (DIMMs) The standard 64 MB of memory in the
printer can be expanded to up to
192 MB using the additional DIMM slot.
32 MB
C7845A
Memory upgrades (DIMMs) 64 MB Q1887A
Memory upgrades (DIMMs) 128 MB C9121A
Font DIMM (100-pin) You can install an 8 MB language font
ROM in the DIMM slot. Visit http://www.hp.com for DIMM
availability and ordering.
ENWW Memory 177