From: bqt@update.uu.se (Johnny Billquist)
Subject: [pups] (no subject)
Date: Wed, 26 Feb 2003 14:04:39 +0100 (CET) [thread overview]
Message-ID: <Pine.LNX.4.21.0302261358240.23561-100000@Tempo.Update.UU.SE> (raw)
In-Reply-To: <001c01c2dd92$2c23e9b0$77b95b8b@ics.forth.gr>
On Wed, 26 Feb 2003, Christos Papachristou wrote:
> A few questions from a newbie:
> I have installed 2.9BSD on a microPDP11/73 with an RD52, using the MSCP
> version of Jonathan Engdahl. After startup the kernel
> indicates 160kb of memory .I am not familiar with such an old unix to
> find out the details but I understand it as 256k minus the kernel. The memory
> is M8067-LF i.e. 512k Qbus. Does this mean that the system can't see the
> rest of it and that I have configure/recompile the kernel?
> The system seems anyway to run fine.
Are you sure it's reporting bytes, and not words?
> I haven't seen an operational PDP with UNIX before this,
> so I can't judge its speed. When in single user mode it seems to
> me that it runs "fast". However upon entering multi user mode the speed
> drops dramaticaly. I have not yet compiled in the 8 port multiplexer
> (DHV11-A), so only the console is functional and thus no gettys are
> loaded. So ,why is there such a change in speed? Does the multiuser mode
> just rise the nice value of the console tasks?
There shouldn't be a big difference in speed. Are you starting some heavy
demons?
> Some information on the system. It is a KDJ11-B (M8190 -no suffix) i.e. an
> 11/84. So, the label on the system says microPDP11/73 (in an BA23 enclosure)
> the cpu is an 11/84 (if the FPU socket is the DIP-40 slot then it is
> unused), and the 2.11BSD second stage boot (version from vtserver) I
> have tried indicates 11/83. The memory is after the CPU and is Qbus (M867-LF).
> If I have understood what I have read in the list, this must be a mixed
> system that could use PMI memory, but just uses Qbus?? What exactly is my
> system?
There exists a specific 11/73 CPU card, but we'll ignore that for now.
The 11/73, 11/83 and 11/84 all use the same CPU card.
The differences are in other areas, and cannot always easily be detected
by software.
The difference between an 11/73 and 11/83 is if the system have Qbus
memory or PMI memory. The difference between an 11/83 and 11/84 is if the
system have the KT84 (or whatever the card is called, my memory fails me
at the moment) Unibus map, which is a Q-bus to Unibus converter along with
the Unibus map required. The CPU is always on a Qbus, but in the 11/84,
nothing but CPU and PMI memory is on this bus.
> Moreover the MSCP controller (M8639 YP i.e. RQDX1)
> the serial port multiplexer(M3104 i.e. DHV11-A) and the memory are Qbus while
> the cpu board is indicated as Unibus in the field guide. Can these two bus type
> s be mixed? (If yes , i would be tempted to abuse the dead VAX11/780 in the
> basement. Can this be done?).
No.
As stated above, the CPU card is actually always Qbus. In the 11/84 you
have a bus adapter to connect the Unibus.
> Anyway, I thought that the best choice of
> a UNIX for it since it only has an RD52 woulbe 2.9 BSD with MSCP support.
> Was this a good guess?
Yes, since you probably don't want to pay a lot of money to Mentec for one
of their OSes. 2.11 is much nicer, but you'll want more memory and disk
space for that.
Johnny
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at update.uu.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
next prev parent reply other threads:[~2003-02-26 13:04 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-02-26 12:25 Christos Papachristou
2003-02-26 13:04 ` Johnny Billquist [this message]
2003-02-26 16:57 ` Christos Papachristou
2003-02-26 15:17 ` David Evans
-- strict thread matches above, loose matches on Subject: below --
2003-02-19 12:18 Christos Papachristou
2002-03-21 9:47 Arda Ulas Unlu
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