Changing wire-wrap configurations on DEC circuit boards

Jerry Weiss jsw at
Mon Feb 13 20:33:47 CST 2017

> On Feb 13, 2017, at 7:29 PM, allison <ajp166 at> wrote:
> On 02/13/2017 06:45 PM, Earl Evans wrote:
>> Hi there,
>> I've got a couple of DEC QBUS boards (including a quad SLU) for which
>> configuration is set by wire-wrap jumpers. I don't have a wire-wrap tool,
>> and have found that trying this by hand without one is not workable.
>> Has anyone come up with a clever way to permit reconfiguration of these
>> boards without semi-permanent changes? Or, alternatively, what wire-wrap
>> tool would you recommend?
>> Thanks!
>> - Earl
> I use wirewrap as the spacing and distance between boards does not
> permit anything else.
> OK too makes a good simple hand tool and more elaborate ones as needed. 
> Its worth the
> tool even if you go with the simple hand tool that looks sorta like a
> screwdriver. 
> Keep in mind with Qbus unless you insert grant cards you can't double
> space boards.
> I only have  8 Qbus systems from LSI-11 through MicroVAX. 
> Allison

There are two common types of wirewrap - Regular and Modified.  

The “modified” wirewrap  tool leaves an insulated turn at the start of
the wrap.  It’s my preference when wire-wrapping 30 gauge or
if you run the wires off board.  Suggest 24 or 26 gauge for the latter.

Make sure you match the wire and tool.  


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