Subject: Re: DECsystem 5500 (was Re: system 5900)
To: Greg A. Woods <>
From: Dave McGuire <>
List: port-pmax
Date: 08/14/1999 00:46:28
On Fri, 13 Aug 1999, Greg A. Woods wrote:
>>   It wouldn't be a grant card if it had resistors on may be a bus
>> terminator of some sort, but qbus doesn't really require termination as I
>> recall.
>DEC Unibus certainly requires termination.  I'd be surprised if qbus
>didn't as well, but then I never had a working qbus system (only enough
>surplus LSI-11 cards that I might have been able to build one if I'd
>ever found the time and a backplane...)

  Unibus definitely does.  And while certain buses like SCSI will sometimes
work without proper termination, Unibus...well, doesn't.  At least not that
I've ever seen.

  Q-bus machines, however, I've never seen any sort of bus terminators for. 
I've two running Qbus systems here in the room with me, for example, neither of
which have terminators in them.


            -Dave McGuire