13 Oct
2016
13 Oct
'16
10:39 a.m.
I thought the question about the prevalence of .156" connectors in early
systems was interesting and I assume someone here has the detail on the
rationale.
Jim
-------- Forwarded Message --------
Subject: CBM edge connectors pitch?
Date: Thu, 13 Oct 2016 19:31:47 +0200
From: silverdr at wfmh.org.pl
Reply-To: cbm-hackers at musoftware.de
To: cbm-hackers at musoftware.de
Do we know what is the norm used in the CBM edge connectors? Like the IEEE, USER PORT or
CASSETTE?
I found out mentions that it uses a 0.156" pitch. Where the heck does that come from?
Nothing "round" in either metric or imperial..
--
SD!
Message was sent through the cbm-hackers mailing list
13 Oct
13 Oct
10:48 a.m.
New subject: CBM edge connectors pitch?
I thought the question about the prevalence of
.156" connectors in early
systems was interesting and I assume someone here has the detail on the
rationale.
I have wondered if it's an approximation to 0.15625" -- 5/32" pitch.
-tony
12:56 p.m.
New subject: CBM edge connectors pitch?
On 2016-Oct-13, at 10:39 AM, Jim Brain wrote:
I thought the question about the prevalence of
.156" connectors in early systems was interesting and I assume someone here has the
detail on the rationale.
Jim
-------- Forwarded Message --------
Subject: CBM edge connectors pitch?
Date: Thu, 13 Oct 2016 19:31:47 +0200
From: silverdr at wfmh.org.pl
Reply-To: cbm-hackers at musoftware.de
To: cbm-hackers at musoftware.de
Do we know what is the norm used in the CBM edge connectors? Like the IEEE, USER PORT or
CASSETTE?
I found out mentions that it uses a 0.156" pitch. Where the heck does that come
from? Nothing "round" in either metric or imperial..
--
SD!
Message was sent through the cbm-hackers mailing list
The 0.156" is presumably the oldest PCB edge connector, I have an example in tube
equipment going back to 1959.
Very common in all sorts of equipment through the 60s and 70s.
As Tony suggests, it matches up with 5/32" spacing, just as 0.125 is 1/8".
Where the rounding of the 1/4 thou (0.00025) took place - in the name or the
implementation - I'm not sure.
3:07 p.m.
New subject: CBM edge connectors pitch?
On Thu, Oct 13, 2016 at 1:56 PM, Brent Hilpert <hilpert at cs.ubc.ca> wrote:
As Tony suggests, it matches up with 5/32"
spacing, just as 0.125 is 1/8".
Where the rounding of the 1/4 thou (0.00025) took place - in the name or the
implementation - I'm not sure.
Implementation. Years ago I verified with several vendors that the
connectors really were engineered for 0.156" or 3.96mm, not 5/32" or
3.97mm. (I'm not 100% certain that was always true, but it was when I
inquired.)
It doesn't make much difference in practice. The highest pin-count
.156" connector I've ever dealt with was 86 pin (43x2), and the
difference in the nominal first-to-last position is only 10.5 mils,
which is on the order of the non-cumulative position tolerance.
I just happened to look at the drawing for a TE 2-530666-1 connector,
and they specified the pitch in one place as 0.156/3.96 (in/mm), and
in another place in the same drawing as 0.156/3.175. Oops!
3:12 p.m.
New subject: CBM edge connectors pitch?
On 10/13/2016 3:07 PM, Eric Smith wrote:
It doesn't make much difference in practice. The
highest pin-count
.156" connector I've ever dealt with was 86 pin (43x2), and the
difference in the nominal first-to-last position is only 10.5 mils,
which is on the order of the non-cumulative position tolerance.
If these are the
connectors that can have keys inserted between every
connector, the small difference would be significant as those would not
align between a metric connector and an English (inch) board. The
electrical connections would line up w/o any keying as you say.
14 Oct
14 Oct
7:05 p.m.
New subject: CBM edge connectors pitch?
On Thu, Oct 13, 2016 at 4:12 PM, jim stephens <jwsmail at jwsss.com> wrote:
If these are the connectors that can have keys
inserted between every
connector, the small difference would be significant as those would not
align between a metric connector and an English (inch) board. The
electrical connections would line up w/o any keying as you say.
Assuming you use the center as your reference point, on the maximum
width (86-pin) connector, nothing is going to be off by more than 5.25
mils. That's not enough to cause a problem with keying.
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5 comments
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participants (5)
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ard＠p850ug1.demon.co.uk -
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