Mystery Ancient HP Memory Modules



#5

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?


#6

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.

#7

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?

#8

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:

**vp


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