MMJ and custom cables (was: Re: DEC 3000 300X/300)

From: Jonathan Engdahl <jrengdahl_at_safeaccess.com>
Date: Fri Jan 3 15:56:29 2003

You can find MMJ cables and connectors in stock at www.l-com.com.

To connect a PC to a KDJ11-SD (PDP-11/53, for communicating via VTserver or
Kermit), get a REC096FD unassembled connector kit for $6.95 and a TDC067-7D
cable for $3.55. Assemble the connector like so:

MMJ end : DB9 end
yellow----------2
black-----------3
green-----------5

Solder white to blue. Cut the DB9 pin off red, strip some insulation off the
middle of green, and solder red to it. Wrap tape around exposed joints.

This won't work for the DB9 on the back of a VAX -- I'm pretty sure that has
a different pinout than the PC DB9.

I also use this cable with some gender benders and null modems to connect a
VT420 to the DB25 on the back of the 11/23 or whatever PDP I happen to be
working on at the time. With a set of about 7 adapters you can connect
anything to just about anything. The adapters are pretty cheap at Cyberguys.

L-com also has the crimper and bare MMJ connectors, but for the cost of a
crimp-it-yourself kit you can buy a lot of preassembled cables. They even
have an MMJ A-B switch. I wonder why they carry these items, and how long
they will continue to stock them?

--
Jonathan Engdahl
----- Original Message -----
From: "Tothwolf" <tothwolf_at_concentric.net>
To: <cctalk_at_classiccmp.org>
Sent: Tuesday, December 31, 2002 11:47 PM
Subject: MMJ and custom cables (was: Re: DEC 3000 300X/300)
> On Tue, 31 Dec 2002, Robert F. Schaefer wrote:
> > From: "Don Mitchell" <runtime_at_wzrd.com>
> >
> > > MMJ connectors are easy to find, and DB25 - MMJ adaptors are also easy
> > > to find.  Then, all that's needed is 6 conductor flat cable, also easy
> > > to find, and an MMJ crimper -- not very easy to find, and expensive.
> >
> > FYI, Ideal Industries makes an RJ45 & MMJ crimper, cat no. 30-497
> > (http://www.idealindustries.com/dc/Tool.nsf, about halfway down), that
> > can be had for less than US$40.
>
> Ideal also makes a MMJ compatible die set for those of us who already own
> a compatible ratcheting crimper. The cost for the die set is around $15 or
> less depending on the sales vendor.
>
> Since we are on the subject of cable building, I'd like to find out just
> how much demand there is out there for MMJ and other such hard to find/
> custom cables for classic computers. I've been considering purchasing
> tools and materials to build some of these cables, and if demand is high
> enough, I'd be willing to build such cables for the cost of materials plus
> a nominal amount for other classic computer enthusiasts. This would
> certainly help me justify purchasing the required tools and materials, and
> would also make some of these hard to find cables easier to obtain.
>
> -Toth

Received on Fri Jan 03 2003 - 15:56:29 GMT