Logic trainer finds - test-drb@ccmp.vtda.org

20 Aug 2007

-----------Original Message(s):

Message: 4
Date: Mon, 20 Aug 2007 09:09:08 -0700
From: "Vincent Slyngstad" <vrs at msn.com>
Subject: Re: Logic trainer finds

From: "Ethan Dicks" 
...
  On 8/20/07, William Donzelli wrote:
  A double-header hamfest weekend yielded a couple
of vintage digital
 logic trainer items. The first is one of those little wood boxes DEC
 Logic labs, but who cares about that.  
 _I_ care about it... I had the manual for one when I was about 12.  I
 learned digital logic on paper from it.  I always wanted one, but the
 books were much easier to find than boxes.

 Every once in a while, I entertain making one of my own, but haven't
 ever come up with an inexpensive and robust plug/connector scheme. 
I have one of these, and the wires with the plugs are a problem.  Mine 
came to me with only a few of these left, and I haven't been able to 
replace them.  For those who've never seen one (but care), there are
eyelets/rivets which are sized appropriately for a mini-banana plug, 
set into the lab box to form the connection points.  Then, a kit of 
various lengths of wire is provided.  The wires end on both ends with 
something similar to the male pins from a large AMP connector or the 
like.  The thing is, they have an unusual tapered shape, rather than 
a simple cylinder, which allows them to wedge into the eyelets nicely.  
The pins appear to be brass, and the eyelets look like they might be gold 
plated(?).

I (and probably others who own one) would love to get some more of the 
wires, or at least a source for the tapered pins to make new wires.

If the tapered pins were available, I suspect brass eyelets could be 
used for an inexpensive (and almost authentic) plug/connector scheme.
(Mini-banana plug hardware seems to be the antithesis of inexpensive!)

    Vince

-----------Reply:

Burroughs used this sort of thing in some old patchboards; I wonder if
by chance they're the same size? The diameter of the hole is a tight 1/16"
drill bit FWIW; the tapered pins are tinned though, not brass.

mike