[sdiy] Amphenol edge card connector sides touch?

[Laughing Man]

They probably shorted as a way for early computer buses made of these
connectors to keep going down the line when a card wasn't in the slot.
Early stuff like S-100 bus were entirely modular computers that would tap
the line off for interrupts or one of the other many controls set on those
bus lines, and break the flow by sinking it. So, if there wasn't a card in
that slit, it'd want to keep going down the line of connectors that were
all in parallel. Yeah, what's happening to yours is probably the intended
design of the connector.

On Sat, Mar 19, 2022 at 11:42 AM Brian Willoughby <brianw at audiobanshee.com>
wrote:

> This matches computer edge card connector circuits I've seen from a
> certain era, but now you have me wondering:
>
> Was the Buchla 200 series designed for this shorting of opposed terminals?
> I've never owned one...
>
> Brian
>
>
> On Mar 19, 2022, at 09:35, Oren Leavitt wrote:
> > Yes. The terminal pairs normally short on these type connectors when
> cards are removed. At least all that I've seen. Power supply lines are
> usually connected with same voltage on each terminal pair or one side not
> connected.
> >
> > Best bet may be to put a dummy card in unused connectors.
> >
> > - Oren
> >
> > On 3/19/22 8:02 AM, mark verbos wrote:
> >> Hi there,
> >>
> >> I have a Buchla 208 I built from parts from Buchla’s garage sale. I
> used the proper (expensive as hell) Amphenol 225-22821-110 edge card
> connector for the card slot on the front panel. The pins from the two sides
> are touching each other when no card is installed, causing the module to
> short power out. Is this normal for these connectors? Is there a way to
> stretch it out? Anyone have experience with this?
> >>
> >>
> >> Mark
>
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