UNIBUS/QBUS interface chips Was: Re: MEM11 update

allison ajp166 at verizon.net
Mon Dec 5 19:53:46 CST 2016


On 12/05/2016 06:35 PM, Toby Thain wrote:
> On 2016-05-02 9:48 AM, Noel Chiappa wrote:
>>     > From: Pete Lancashire
>>
>>     > Do you or someone have a list of all the Unibus bus chips ?
>>
>> I have seen the following bus interface chips used on DEC UNIBUS boards:
>>
>> Drivers:
>>
>> 8881 - Sprague, Signetics - Quad NAND
>>
>> Receivers:
>>
>> 380 - Signetics - Quad NOR
>> 314 - Signetics - 7-input NOR
>> 8815 - Signetics - 4-input NOR
>> 8837 - National Semi - Hex receiver (aka Signetics N8T37)
>> 8640 - National Semi - Quad NOR
>>
>> Transceivers:
>>
>> 8641 - National Semi - Quad transceiver
>>
>> The actal complete part number can vary depending on the
>> manufacturer; e.g.
>> the 8641's are usually DS8641N, from NatSemi, and the 380's are usually
>> SP380A's or SP380N's. Where the basic number is not included (as with
>> the
>> 8T37 for the 8837) I have given it.
>>
>> The following chips have been used by DEC to interface to the QBUS, and
>> I have seen many of the above chips (e.g. 8641's) used there too, so I
>> think chips seen on one bus could be used on the other:
>>
>> Drivers:
>>
>> 7439 - Various - Quad NAND
>>
>> Transceivers:
>>
>> 2908 - AMD - Quad latching transceiver with tri-state output
>>
>> I _believe_ the following chips are also usable as UNIBUS/QBUS interface
>> chips, but I'm not sure if I've seen one used there:
>>
>> Transceivers:
>>
>> 8836 - National Semi - Quad NOR
>> 8838 - National Semi - Quad transceiver (aka Signetics N8T38)
>>
>> Quite a zoo!
>>
>>     Noel
>>
>
>

Also 74LS240, 7438,     DM8130, dm8838, and Andromeda (the guys that use
the AM29x305) liked the AM2908.

> Has anyone looked at the TI Signal Switch family for QBus? (hat tip
> Ian Finder)
>
> http://www.prnewswire.com/news-releases/three-new-bus-switch-families-from-texas-instruments-enhance-performance-of-datacom-and-networking-equipment-and-optimize-next-generation-portable-computing-and-communications-designs-70812102.html
>
>
Not the best animal as the are CMOS.

A bunch of us old digits (former dec engineers) got together and were
talking
about old systems and the thing that stood out is a general dislike for
having
to use the limited set of bus interface chips when there were newer
parts.  It
was a internal mandate not something that was better than could be had. 
The
logic was the parts were known, the vendors vetted for quality and
reliability
and when you use hundreds of thousands to millions of a part like bus
interface
and ram quality is a critical thing.  Were they special, a flat no.

But next time you look at an LSI-11/2 dual width processor card look at
the line of
caps that are on the bus, they are there to tame the ringing.

Allison

> --Toby
>
>
>




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