A 'good-enough' H960 |d|i|g|i|t|a|l| PDP11 masthead replica

[william degnan]

No one can see it, just use painted wood or something that holds it in
place, eh?

On Thu, Jul 9, 2015 at 8:18 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu>
wrote:

>     > From: Steven Malikoff
>
>     > a replica PDP11 masthead panel for the DEC H960 rack.
>
> That would be great! (I'd buy one! Or more!) But how are you going to
> produce
> the plastic housing? I suspect that's going to be harder than the inset
> coloured panel.
>
>     > I need some help from the list, if possible - I would like the
>     > dimensions of the width and height.
>
> The inset (the coloured part) is 8.45 cm high (it's slightly smaller than
> the
> inset in the plastic housing, by about .5 mm); alas, I don't have a metric
> ruler long enough to measure the width directly, but in Imperial it's
> 3-21/64" by 18-9/16".
>
> I don't have a good way to accurately measure the radius in the corners,
> but
> it seems to be about 8.5 to 9.5 mm.
>
>     > I also would like to know of the outer edge of the masthead is a
> beige
>     > colour, or even silver.
>
> The raised edge around the inset panel is painted a dull silver - like the
> old
> silver paint, but with a touch of grey in it. The edge itself is 4.1mm
> wide,
> according to my calipers.
>
>     > The panel would be the inner bit with the radiused corners, the edges
>     > being a seperately cut panel which is in front of the the detailed
> one.
>
> Not sure I follow this? The entire top unit, including the raised edge
> around
> the coloured inset, is a moderately complex injection moulded plastic
> piece;
> behind the front, it's kind of like a box that's open at the back, and
> there's
> a ridge around the back edge on three sides; the bottom edge is shorter,
> and
> the top edge is extended further back. Finally, there are a couple of
> internal
> tabs where it actually connects to the H960.
>
> If you want an original to copy, TopLine has one for sale on eBay (ignore
> the
> ridiculous price they've got on it, they are very reasonable).
>
>     > I would also like to know how deep the recess is for the front. I
>     > suspect the same as the filler panel bezel edge, about 3mm.
>
> 4.0 mm by my 0.5 mm ruler.
>
>     > And also the depth of the plastic backing.
>
> You mean, how thick is the plastic in the housing? 2.7 mm in one place, 2.8
> mm in another, 2.3 mm in a third?
>
>
> Interestingly, IYWR, in previous thread we'd mentioned how other people
> produced their own insets; one for a terminal server, and one for the LISP
> Machine. I looked at my LISP Machine one, which I had assumed was in a
> similar housing, but it's not! It does indeed fit on an H960 (the early
> LISP
> Machines were built in H960's), but it's quite different.
>
> It's in an extruded aluminium unit (of constant cross-section), with no end
> pieces (although the bottom plate has small squared cut out of the
> corners);
> the extrusion's cross-section is exact a capital 'F', but upside down.
> There
> are little square 'serifs' on the 'back' of the 'F' (the front side, when
> installed), and the printed panel fits in between them.
>
> Now that I look at it, it looks very similar to me to some things I seem to
> vaguely recall being used on earlier DEC machines (either a PDP-6, or a
> KA-10, I don't recall where it looks familar from). It being a
> more-expensive
> aluminium extrusion makes sense; that was back when that sort of thing
> (along
> with lots of lights! :-) was acceptable.
>
>         Noel
>