Edge connectors (was Re: Teaching kids about computers...)

Roy J. Tellason rtellason at verizon.net
Tue Nov 27 10:47:52 CST 2007

On Monday 26 November 2007 18:28, Ethan Dicks wrote:
> On Mon, Nov 26, 2007 at 01:42:36PM -0500, Roy J. Tellason wrote:
> > On Saturday 24 November 2007 23:31, Ethan Dicks wrote:
> > > The User Port on all the C= machines is more-or-less the same... 12x2
> > > 0.154" edge connectors.
> >
> > I thought those were 0.156"?
> Oops... my fingers were probably thinking 25.4mm to the inch when I
> mistyped the 4.
> > I'm trying to remember what all edge connectors used to be common.  I'm
> > thinking that 0.1",  0.125",  and 0.156" were some of the more common
> > sizes of connector finger out there.
> Those all sound common.
> > And how many pins?
> Various ones... For the C= line, 6/12 and 12/24 were common (cassette
> port, User Port, IEEE-488), but the VIC-20 had a 22/44 @ 0.156" expansion
> connector.  The C-64 was much smaller, but I can't reliably recall the
> numbers off the top of my head, so I won't guess.

I *think* that was also a 44-pin connector,  but at smaller spacing.  I'd have 
to look to be sure though.

> >  Seemed to me there was an awful lot of stuff out there that used 22/44
> >  pins of 0.156" spacing. 
> Very common.

Yes,  Radio Shack even used to sell boards that were set up for that 
connector,  and the connectors themselves,  in both soldertail and wire-wrap 
versions.  I have a rackmount box somewhere that has room for a bunch of 
those,  though it won't take the very tall cards.

> My COSMAC VIP has a pair of those (one for memory, one for I/O expansion),
> and there was a standard RCA CPU board that used it as its off-board bus
> connector.  There was the STD bus, and I'm sure many more examples from the
> 1970s and 1980s. 

I'm thinking STD bus was more pins,  56 maybe?

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