Path: utzoo!censor!geac!jtsv16!uunet!tut.cis.ohio-state.edu!rls!randy
From: randy@rls.UUCP (Randall L. Smith)
Newsgroups: comp.sys.dec
Subject: Re: Questions on 5400 systems
Summary: dssi is no bus, no Jack Kennedy either.
Keywords: 5400, vax, risc, ultrix, 3000, dec
Message-ID: <356@rls.UUCP>
Date: 9 Aug 89 03:17:09 GMT
References: <106@pserv.UUCP>
Distribution: usa
Organization: A maze of twisty passages all alike in Columbus, Ohio.
Lines: 39
In article <106@pserv.UUCP>, stevem@pserv.UUCP (Steve Mestad) writes:
> Our sales reps state that the 5400 qbus can run 8 meg and disk io will
> be about 2.5 times better than on our Microvax II's. Has anyone
> experienced this? How fast do the dssi drives run....or is the kda a
> better way to go?
Dssi is far better because the i/o's do not go to the q-bus. The controller
is "built-in" to the processor card. Naturally, the disk connects directly
to the controller. Since the QIO's and data don't travel over the bus, its
much faster.
> How are the connections brought out?
>
> Does the 8 meg bus in the 5400 eliminate the use of existing cards due to
> its faster speed?
>
> Or do the third party 3000 series card run fine in the 5400??
The Q-bus is still in place and available for kda50's and other dog type
controllers. The connections are either Q-bus or the dssi slots. dssi is
bus-less, that is, it is *not* a bus. It is a controller on the processor
card. Once all the dssi slots are used, thats it. No further expansion is
possible. I think there are typically four dssi slots. I am not familiar
with the 5xxx series. A limitation of dssi is that only dssi drives can be
used with it. The Q-bus can utilize SMD, ESDI, tapes, etc.
> How about the Risc Ultrix? Full of porting bugs or identical to the
> Vax Ultrix? Third party applications getting ported or are they too busy
> or not interested.....
Don't know but a good question. If anyone knows, I'd like to hear too.
Cheers!
- randy
Usenet: randy@rls.uucp
Bangpath: ...!osu-cis!rls!randy
Internet: rls!randy@tut.cis.ohio-state.edu