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From: slsw2@cc.usu.edu
Newsgroups: comp.sys.dec
Subject: Re: Can one put standard Q-Bus memory in the PMI bus of an 11/84?
Message-ID: <1991Apr29.115821.47601@cc.usu.edu>
Date: 29 Apr 91 17:58:21 GMT
References: <72943@eerie.acsu.Buffalo.EDU> <1991Apr26.191350.47574@cc.usu.edu> <73510@eerie.acsu.Buffalo.EDU>
Organization: Utah State University
Lines: 31

In article <73510@eerie.acsu.Buffalo.EDU>, kalisiak@acsu.buffalo.edu (christophe m kalisiak) writes:
> In article <1991Apr26.191350.47574@cc.usu.edu> slsw2@cc.usu.edu writes:
>>In article <72943@eerie.acsu.Buffalo.EDU>, kalisiak@acsu.buffalo.edu (christophe m kalisiak) writes:
>>> I have a couple standard Q-Bus MSV11-L, MSV11-P memories which I would
>>> like to use in my 11/84, but I don't know if anything detrimental
>>> will happen.
>>> 
>>> Can I use the -L and -P memories (I don't feel like buying any -J or -Q
>>> memories. :-( ) in the 11/84? Will it slow the system down any by
>>> using non-PMI memory?
>>
>>Sorry. The Q-bus doesn't do much in the 11/84. You can't put memory on it.
> 
> Sorry, but I don't understand what you are saying. 
> The 11/84 has a Q-Bus CPU, which is the same as the 11/83. Therefore,
> one should be able to put Q-Bus memories in it, albiet with some reduction
> in speed.
> Also, what do you mean by "you can't put memory on it"? Of course you can!
> If you couldn't, the 11/84 would probably not have sold very well...

Well, the 11/84 kind of has a QBus CPU. With the UNIBUS adapter installed in
the 11/84, the QBus doesn't do anything other than transmit addresses across the
PMI. I've tried plugging QBus things into the 11/84; it don't work. The
UNIBUS adapter asserts a signal on the CD interconnect that tells the
processor it's not a QBus machine anymore.

Besides, even if QBus memory did work in the 11/84, the UNIBUS couldn't talk
to it.

Roger Ivie
slsw2@cc.usu.edu