[Info-vax] MMJ to Serial cable

[Dave Froble]

On 3/31/2021 6:43 PM, Mark Redding wrote:
> Thanks, Trouble is a) I don't have the cable or the adapter (which is why I bought the boots and then butchered a DB9 female to female cable), and b) being UK based I've found the shipping to be prohibitively expensive from the US (I tried to order a cable costing $28 and they wanted $120 to ship it).
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> M
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>>> I've recently unearthed an old VAXstation 4000 vlc that I used for many years at work in the 1990's. When I left the company I was able to take the VAX with me along with an MMJ lead plus a DB9 adapter. Sadly I've been unable to locate the cable so was interested to know if anyone had a wiring diagram for MMJ6 to DB9.
>> The part you need is H8571-J:
>> https://www.lammertbies.nl/comm/cable/dec-mmj
>> http://www.pacificcable.com/Picture_Page.asp?DataName=H8571-J

I always made my own.  Not a problem.

In the first URL above it specifies the pin outs for the MMJ.  Note that 
the connection must reverse all the leads, ie; XMT to RCV and RCV to XMT.

You don't need a converter, just a blank DB9 plug, and solder or crimp 
pins.  Not sure if the second URL actually described the DB9 pins.  If 
you cannot find this, ask, and I'll dig up my instructions.

As for cable, just use any 6 conductor twisted pair cable, if you cannot 
find 6 conductor flat cable.  The usual length doesn't need twisted 
pairs.  8 connector cable can be used, ignore 2 wires.

-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
DFE Ultralights, Inc.
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