ISO: VAXBI hardware

Ethan Dicks ethan.dicks at
Wed Sep 21 15:03:42 CDT 2016

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'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.  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.

> 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.

> 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.


More information about the cctalk mailing list