ISO: VAXBI hardware

Josh Dersch derschjo at
Wed Sep 21 22:42:04 CDT 2016

On 9/21/16 1:03 PM, Ethan Dicks wrote:

> On Wed, Sep 21, 2016 at 3:48 PM, Josh Dersch <derschjo at> wrote:
>> Hi all --
>> I have a VAX 8250 I'm bringing up and I'd like to track down an Ethernet
>> adapter, this would be the T1034 (DEBNT).  There are a few on eBay, but
>> none include the cabling and bulkhead, which would be nice to have.
> I think I came upon one of those many years ago and never managed to
> get the cabling working (the module shows up).  I'd love to hear about
> any resolution on this.
I'll let you know.  I have a DEMNA (XMI Ethernet) boardset with 
cable/bulkhead which is completely useless to me as I don't have a 
compatible VAX.  The cabling looks like it might be compatible with the 
DEBNT but I haven't found a pinout anywhere to check.  (If anyone wants 
to trade, let me know...)

>> I'm also looking for a T1010 (BI to Unibus adapter), as the one in my
>> system is shot (and given the lack of documentation, I doubt I'm going to
>> be able to fix it).
> I have a couple of broken T1010 boards - the damage was obvious -
> something messed up with the cabling caused some sort of high-current
> fault that cracked a specific DEC IC and fried the trace going to the
> part.  If you have one that "doesn't work", it depends on what's
> really going on as to how "fixable" it is.
The yellow LED does not light, and it's reported as device code FFFF in 
the VAXBI configuration.  Self-test hangs for ~30 seconds waiting for 
the T1010 to do something.  So it's not real happy right now. Nothing 
looks to be visibly damaged.

> I now have a good set of
> cables, a good T1010 module, a good DD11-DK, and three bad M9313 UET
> boards.  I know they are bad because I can follow what docs _are_ out
> there, bang on some BI registers and see that it's failing self-test
> in a specific way that means "I can't talk to the UET".  If you can
> talk to the BI chip on your T1010 board (the state of the yellow LED
> is not indicative of that), then you might be able to learn something
> about what's failing.  If you can't talk to the BIIC, they are
> socketed and you could try swapping it with one from another board.
> There are a couple of revs of the BIIC.  I've never known that it
> makes much practical difference, but just be aware there are stamped
> revision letters on the chip.
> As mentioned, besides the T1010, you'll need 4x 30-pin cables, and a
> paddle card to the front of a DD11, and the DD11 itself - mine is in a
> BA11-K next to the cabinet with the 8250 BA32, but I know that there
> were also some BA32 with one BI cage and one DD11-DK.  I do not know
> how those are powered or wired in.  You'll also need a working M9313.
> That's the specific reason I'm trying to get a Unibus PDP-11 working
> right now - to test my M9313 cards and verify any repairs.

Ah.  I have the T1010, the cabling, the DD11 in a BA11-K, but what I 
thought was the appropriate paddle in the DD11 isn't -- it's an M9014.  
Which will work with my VAX-11/750, so I guess I'll hold onto it :).  So 
I guess I have less of a reason to track down a T1010 at the moment...

>> Also -- any suggestions for mass storage?  I have a KDB50 (T1002, T1003
>> set), but SDI drives are getting harder to find.
> I still owe you a list and/or picture from my external SDI<->ESDI box,
> but, yeah, SDI drives aren't getting more abundant.
Thanks :).  Whenever you have the time, no big hurry.  It's not like 
ESDI drives are falling from the trees :).

>> I assume VAXBI SCSI
>> adapters are even more scarce than their Unibus counterparts....
> ISTR back in the day, new, a VAXBI SCSI board was $10,000.  I have
> never seen one in person.
There's one on eBay, but the seller wants $1200 for it so I think I'll 

Thanks for the information!
- Josh
> -ethan

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