Mystery Ancient HP Memory Modules


I have some HP memory modules, marked 1818-2805, with a big number 5 on them, and saying Hewlett-Packard, these look like 1970s or so, ceramic chip packages with a plastic holder around them, anyone know anything?


Is the plastic holder roughly of the size 2.5"x4.5"x0.75" ? Then it's propably a ROM module for a 9810 or 9820. If the size is 2.9"x4.4"x0.6" it's a ROM for the 9830.


Long narrow modules? If so, I think they are HP 9845 ROMs. Do the labels have either a green or black background? Is there a conspicuous white triangle, square, or circle on the label?


Looks like one of the 14 OS ROMs for the 9825A.

Unlike later models (B and T), the A model had a drawer
on the left side. This drawer contained 14 plug-in ROMS that had the OS code.

The ROMs look a like the HP-85 ROMs, plastic packges with
holes on the underside. Spikes on the daughterboard enter the holes to make contact with the ROM PCB.

Unlike the 85 ROMs, the HP 9825 OS ROMs have holes all around the edges.

I don't have a picture of the 9825 ROMS, but here is a picture of the 85 ROM drawer:


Possibly Related Threads...
Thread Author Replies Views Last Post
  HP Prime - Short "learning" modules CR Haeger 1 280 11-27-2013, 02:13 PM
Last Post: Jonathan Cameron
  Library#4 Modules mass-update and New Overlays Ángel Martin 0 302 11-09-2013, 05:55 AM
Last Post: 'Angel Martin
  hp41cv memory modules tim peterson 10 761 11-07-2013, 11:09 PM
Last Post: Garth Wilson
  Another Prime mystery - templates don't work anymore Michael de Estrada 2 352 11-02-2013, 11:34 AM
Last Post: Michael de Estrada
  Best way to test HP-71B RAM modules (the 32K/96K ones etc.)? Philippe Lasnier 4 563 09-25-2013, 09:54 AM
Last Post: Philippe Lasnier
  HP-41 New versions of your favorite modules - with an AOS twist :-) Ángel Martin 13 888 06-21-2013, 01:29 PM
Last Post: Diego Diaz
  Programming CMT EPROM modules for HP-41 Paul Berger (Canada) 4 437 01-22-2013, 06:04 PM
Last Post: Paul Berger (Canada)
  Question about X modules for HP41x Ignacio Sánchez 7 606 12-13-2012, 07:00 AM
Last Post: Geoff Quickfall
  TAS Modules - which are 4K ? Gene Wright 2 276 07-01-2012, 07:58 AM
Last Post: gene wright
  41 User Memory vs System Memory Gerry Schultz 6 511 07-01-2012, 12:02 AM
Last Post: Monte Dalrymple

Forum Jump: