IBM Xstation 140?

Chris Hanson cmhanson at
Fri Nov 2 15:42:53 CDT 2018

On Nov 2, 2018, at 1:22 PM, Electronics Plus <sales at> wrote:
> Memory
> User-installable RAM boards provide the 425 with RAM in increments of 8, 16

> From <>

Yes, I’ve read that, thanks. What I need is the actual *pinout* for the memory boards which is the sort of thing that’d be in a hardware reference manual rather than a user’s manual. (Along with pinouts for the DIO-II expansion slot.)

> If this is standard ECC memory, then I have plenty of it on hand. But HP was known to use some really funky looking memory.

They use standard *memory* on non-standard *boards*.

The ICs are standard, for example in < <>> a 4MB board uses nine 80ns 514256 ICs and a trio of 74AS1004 hex inverter-drivers. However, the boards are not SIMMs, they use a 72-pin header.

My theory is that given they used the same ICs as everyone else, it should be easy to design and fabricate a SIMM adapter from the board pinout.

This RAM also appears to have been used in the HP-9000/375 and /380, in case someone has a hardware reference manual for those.

  -- Chris

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