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From: terry@spcvxb.spc.edu (Terry Kennedy, Operations Mgr.)
Newsgroups: comp.sys.dec
Subject: Re: Can one put standard Q-Bus memory in the PMI bus of an 11/84?
Message-ID: <1991Apr25.170913.1283@spcvxb.spc.edu>
Date: 25 Apr 91 17:09:13 GMT
References: <72943@eerie.acsu.Buffalo.EDU>
Organization: St. Peter's College, US
Lines: 23

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.

  You can use old-style memories in an 11/83, which works but introduces a
large performance hit. You have to make sure the memories have no connection
(not even bus grant, but power is ok) on the CD side.

  I believe this will _NOT_ work in an 11/84. The memory slots are on the
"wrong side" of the CPU, and while the CPU may see the memory, the hardware
on the Unibus side probably won't be able to DMA into there.

> BTW, if anyone has any 11/84 memory which they would be willing to
> sell cheaply, please let me know.

  The older MSV11-Jn boards worked _only_ in 84's, due to a design problem
in one of the gate arrays. You should be able to pick one up for a pretty
low price.

	Terry Kennedy		Operations Manager, Academic Computing
	terry@spcvxa.bitnet	St. Peter's College, US
	terry@spcvxa.spc.edu	(201) 915-9381