DEC UNI/Q-BUS board physical size?

vrs vrs at
Tue Mar 8 16:59:58 CST 2005

From: "Brad Parker" <brad at>
> >
> very nice, thanks.

No problem.

> I'm curious what the holes on the top of the board are for - I have
> about 10 metal hex-width "stiffeners" with extractors I was given by a
> guy who made unibus memory boards - I've yet to measure the holes on
> those.  I assume they end up some how pop-riveted to the board but how
> one fastens them I'm not sure.  I've only used pop-rivets on cars and I
> don't think I want to use the same style fasteners on a PCB.  Maybe
> nylon screws & nuts with some loctite, and trim the excess threads.

Well those may be silly.  What they are is the correct holes for a DEC
double-height handle, replicated three times.  I do not know if they line up
with the stiffener holes, or if that would even matter, as I imagine the
stiffeners are hard to find.

The plastic handles were riveted to the boards.  I have had good luck
attaching them with zip ties, actually (see the "Home" page pointed to at
the top).  That has nearly the mechanical strength of the nylon screw (if
not quite the rigidity), and is simpler.

> Are some sort of plastic handles available?  Any thoughts?

I have a pile of plastic handles, but they have non-DEC spacing.

> I want a "spec" paper drawing with dimensions from the books and then
> verify it with a selection of unibus cards I have.

If only it were that easy.  The manuals I have give some of the spec's, some
with and some without tolerances, etc.  Between the various manuals it is at
least possible to round up the needed basic measurements.

> Have you made a PCB with the hex width card model?

No, I just threw the hex height together in response to the request.

What I have done is made single-height cards, and mock-ups of double-height
cards.  I have drawings for a variety of single and double-height Gxxx, Mxxx
and Wxxx flipchips.

I also have one complete drawing for an RX8E replica (quad height), but I
haven't built one.

(And a whole other library for drawing flip-chip backplanes, but that's
another story.)


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