As Jon said, from my analysis of busted-apart DEC connectors, there's a
selectively plated "pad" where the contact surface actually is.
I wouldn't be surprised if the bulk of the contact fingers is *phosphor
bronze* which is often used in springs. Perhaps we can get Connor to do a
metallurgical
On 08/16/2019 05:59 PM, Noel Chiappa via cctalk wrote:
> From: Brent Hilpert
> I've seen pieces of HP high-end lab equipment from thru the 60s that
> used tin plating on the PCB edge fingers, mating into gold-plated edge
> connectors on the backplane.
ISTR that DEC used
> From: Brent Hilpert
> I've seen pieces of HP high-end lab equipment from thru the 60s that
> used tin plating on the PCB edge fingers, mating into gold-plated edge
> connectors on the backplane.
ISTR that DEC used bronze contacts in their backplanes, but basically all the
On 8/16/19 5:46 PM, Brent Hilpert via cctalk wrote:
> On 2019-Aug-16, at 11:56 AM, systems_glitch via cctalk wrote:
>> On Fri, Aug 16, 2019 at 2:53 PM Paul Koning wrote:
>>>
On Aug 16, 2019, at 2:43 PM, systems_glitch via cctalk <
I'm sure DEC wouldn't have bothered with hard gold
That *is* surprising, HP sometimes gold plated the whole thing!
In any case, I will continue to run edge connectors with the superior
albeit more expensive selective hard gold process :P
Thanks,
Jonathan
On Fri, Aug 16, 2019 at 5:46 PM Brent Hilpert via cctalk <
cctalk@classiccmp.org> wrote:
>
On 2019-Aug-16, at 11:56 AM, systems_glitch via cctalk wrote:
> On Fri, Aug 16, 2019 at 2:53 PM Paul Koning wrote:
>>
>>> On Aug 16, 2019, at 2:43 PM, systems_glitch via cctalk <
>>>
>>> I'm sure DEC wouldn't have bothered with hard gold plating if their
>>> connectors were metallurgically
On 8/16/2019 12:53 PM, Paul Koning via cctalk wrote:
From what I remember, the detailed analysis involves an "electrochemical
series", which has metals like sodium at one end, copper closer to the middle, and
gold at or near the other end. Metals are compatible if their potential value
You can look it up in an electronegativity chart for a quick "will these
ruin each other" check.
I think a lot of this comes from the SIMM era in PCs, where folks were told
to only use gold-flash SIMMs in gold sockets, and only tin plated SIMMs in
tin plated sockets.
Thanks,
Jonathan
On Fri,
> On Aug 16, 2019, at 2:43 PM, systems_glitch via cctalk
> wrote:
>
> I'm sure DEC wouldn't have bothered with hard gold plating if their
> connectors were metallurgically incompatible :P The few busted DEC
> connectors I've replaced did indeed have selective gold plating on the
> contact
I'm sure DEC wouldn't have bothered with hard gold plating if their
connectors were metallurgically incompatible :P The few busted DEC
connectors I've replaced did indeed have selective gold plating on the
contact surfaces. Most quality edge connector slots are similarly
constructed.
Thanks,
On 8/16/2019 12:13 PM, systems_glitch via cctalk wrote:
Dwight,
I spot check boards. I lack sufficiently sensitive instruments to measure
actual thickness (even on a surface plate, it's the same for ENIG as hard
gold with an 0.0001" indicator) but ENIG won't stand up to a few swipes
with an ink
> From: cctalk on behalf of Dennis Boone
> via cctalk
> Sent: Friday, August 16, 2019 8:46 AM
> To: cctalk@classiccmp.org
> Subject: Re: GW-DEC-1: A New DEC Prototyping Board
>
> > I've gotten the distinct impression that US board houses really are
> >
16, 2019 8:46 AM
To: cctalk@classiccmp.org
Subject: Re: GW-DEC-1: A New DEC Prototyping Board
> I've gotten the distinct impression that US board houses really are
> only interested in government/military/aerospace work. I've often
> wondered what it would take to set up a modern
> I've gotten the distinct impression that US board houses really are
> only interested in government/military/aerospace work. I've often
> wondered what it would take to set up a modern "no human interaction"
> line and if one could be even a little competitive with the Chinese
> on it.
Indeed, when I tried to get quotes for the first XT-IDE run, the best
US-based quote I got was around $15/board with a *16 WEEK* lead time.
Compare to my usual "does good hard gold" shop in China, PCB Cart, at
$8/board (final all-in cost) and 12 day lead time, including the initial
tooling fees.
On 08/16/2019 08:59 AM, systems_glitch via cctalk wrote:
Paul,
I've got a board house I usually use, but if I can find a shop in the USA
that will do hard gold plating and provide a comparable cost-per-board, I'd
certainly switch!
There are few board houses in the US anymore, and they are
Paul,
I've got a board house I usually use, but if I can find a shop in the USA
that will do hard gold plating and provide a comparable cost-per-board, I'd
certainly switch!
Thanks,
Jonathan
On Fri, Aug 16, 2019 at 12:55 AM Paul Anderson wrote:
> Hi Jonathan,
>
> If you are looking for
Hi Jonathan,
If you are looking for someone to make the boards, I know someone in CA.
I'll try to dig up his contact info this weekend.
Paul
On Wed, Aug 14, 2019 at 7:14 PM systems_glitch via cctalk <
cctalk@classiccmp.org> wrote:
> Connor Krukosky and I have been working on laying out a new
-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Noel
Chiappa via cctalk
Sent: Thursday, August 15, 2019 12:45 PM
To: cctalk@classiccmp.org
Cc: j...@mercury.lcs.mit.edu
Subject: Re: GW-DEC-1: A New DEC Prototyping Board
> From: Paul Bir
> From: Paul Birkel
> But which bus? There are three ...
So I'm clearly not very awake this morning. I can only think of two major
quad-width DEC standard slots - SPC (UNIBUS) and dual QBUS. What's the third
- PMI? (MUD is hex, as is Fastbus.) Or OMNIBUS, if we're not restricted to
Speaking from experience from having done a few Unibus boards now (none of them
available yet unfortunately) that providing a general Unibus interface on a
quad board will consume a reasonable amount of the board space and limit
flexibility on which driver/receiver/transceiver parts that can be
On 8/14/19 5:13 PM, systems_glitch via cctalk wrote:
> These should be available within a month or so. I'll be putting up a
> preorder soon to gauge interest in the production run
Do all three busses share the same ground pins?
Many proto boards I've seen have ground planes on the board
:
> -Original Message-
> From: cctech [mailto:cctech-boun...@classiccmp.org] On Behalf Of emanuel
> stiebler via cctech
> Sent: Thursday, August 15, 2019 4:23 AM
> To: systems_glitch; General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: GW-DEC-1: A New DEC Prototyping Board
&g
-Original Message-
From: cctech [mailto:cctech-boun...@classiccmp.org] On Behalf Of emanuel
stiebler via cctech
Sent: Thursday, August 15, 2019 4:23 AM
To: systems_glitch; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: GW-DEC-1: A New DEC Prototyping Board
On 2019-08-15 02
On 2019-08-15 02:13, systems_glitch via cctalk wrote:
> Connor Krukosky and I have been working on laying out a new quad-height DEC
> protoboard, which can also be sheared down into a dual-height board. Full
> announce on the VC Forums:
>
>
Connor Krukosky and I have been working on laying out a new quad-height DEC
protoboard, which can also be sheared down into a dual-height board. Full
announce on the VC Forums:
http://www.vcfed.org/forum/showthread.php?71177-GW-DEC-1-A-New-Quad-Height-DEC-Prototyping-Board=582892#post582892
26 matches
Mail list logo
