pdp11/93 DB9 rs232 pinout

Tothwolf tothwolf at concentric.net
Sat Nov 15 08:55:54 CST 2014

On Sat, 15 Nov 2014, Noel Chiappa wrote:

>> From: Henk Gooijen
>> I wanted to connect a VT510 to the console port. All connectors are 
>> DE-9
> Really? The PDP-11/94-E User Guide (EK-PDP94-MG-001), available online 
> in a number of places, shows (pg 46, aka 2-18) the Console/SLU panel, 
> and the Console connector is much larger than the SLU connectors. (The 
> illustration shows a 23-pin D-type connector - presumably an error, it 
> should have been 25.) And here:
> http://www.pdp-11.nl/pdp11-93/rear-panel-small.jpg
> is a picture of one, and it indeed has the 25-pin console connector.
> Although I suppose it's possible they changed the actual hardware at 
> some point, and some real machines have a 9-pin D-type? Or maybe a VAX 
> of some sort uses a similar panel, but with all 9-pin D-types, and 
> someone had stuck on of those on that machine?
>> What worked for me is the "VAX console cable", in other words: that 
>> DE-9 connectors is NOT "PC alike"! You can find the VAX console cable 
>> pinout on the web.
> Good catch! It makes sense that the VAX and 11/93-94 use the same 9-pin 
> D-type pinout; that way they'd only have to have one kind of cable.

If that's the case, then one could also use a H8571-B adapter with a MMJ 
cable to connect the terminal. One thing to watch out for with the H8571-B 
adapters though is that they are thicker than most of the other DB25 and 
DE9 adapters such as the H8571-J, H8575-A, etc so you'd need the ports 
further apart than typical if you wanted to use multiple adapters 
side-by-side. The H8571-B I had laying on the desk is about 7/8" thick at 
the MMJ connector and tapers down in an L-shape to about 5/8" thick at the 
DE9 end.

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