UNIBUS PDP-11 memory expander card

[jwsmobile]

On 1/28/2015 11:02 AM, Noel Chiappa wrote:
> So, I'm in the process of trying to read those old MIT V6 Unix dump tapes
> (with a really big hand from Chuck, who did all the ugly work of actually
> reading the bits off the tapes, for which he has my undying gratitude!), and
> although I'm still trying to figure out what the format is, I did manage to
> retrieve, more or less, a copy of the assembler startup/support file (m47.s; a
> hacked version of m45.s), and it reveals that we were using an Able ENABLE
> card to take our 11/45 out to more than 256KB.
>
> I found a copy of brochure which very briefly describes/shows it here:
>
>    http://archive.org/stream/bitsavers_ablebrochuuctSummary_2920347/Able_Computer_Product_Summary_djvu.txt
>
> and although the picture didn't ring any bells for me, that must be it.
>
> It looks like it has a UNIBUS connector (which I take it is 'UNIBUS out'), and
> also some kind of 'over-the-back' connector which I assume is the bus to the
> memory, which sounds (from a brief mention I found somewhere else) like it was
> standard Extended UNIBUS memory in a separate backplane. (Although I could be
> wrong; maybe the ENABLE plugged into the EUB backplane, and the UNIBUS
> connector is 'UNIBUS in' from the CPU?)
>
> I was unable to locate any real documentation for it online (maybe my
> Google-fu just isn't strong enough), but if someone has any, or can point me
> at any, I'd be grateful.
>
> Any if anyone actually has one, in the flesh, that would be Really Cool!
>
>     Noel
>
>
I sent a bit of this thread along to Ken Omohundro who founded Able, and 
his reply is below.  If he sends anything else along, I'll get it to 
somewhere people can find out about it.

/Wow!/
/
/
/You are talking about 30+ years ago! /
/
/
/Let me check my archives and I'll get back to you./
/
/
/My memory is  not as good as it once was with a long line of 
communication product designs since then. /
/
/
/Our Univerter was our first product that allowed DEC to sell their 
first Qbus processor board in larger quantities since they released it 
before the developed Qbus interfaces for it.  On that design we added a 
register to allow users to access more memory as well.,/
/
/
/Our Cache 45 sat on the fast bus allowing RSTS OS users to improve 
system performance over 50% better./
/
/
/SCAT 45 was a MOS memory we developed to allow us to put a full 128Kb 
of memory on the fast bus instead of the 32Kb bipolar offered by DEC.  
Mad flight simulators faster than anything else as well as many 
scientific and defense applications./
/
/
/Microverter was bidirectional and our most popular bus converter./
/
/
/The Enable and the Magnum was our last bus converter products trying to 
squeeze the last unannounced capabilities of DEC's Qbus processor boards./
/Unfortunately there was not a very big demand for those solutions.  
Which is why the details haven't stayed with me.  I probably have data 
sheets archived and I will scan them as a PDF file and email them to you./
/
/
/Hope that will help./
/
/
/Ken Omohundro/


Thanks
Jim