[pups] (no subject)

Christos Papachristou chpap at ics.forth.gr
Thu Feb 27 02:57:55 AEST 2003

----- Original Message -----
From: "Johnny Billquist" <bqt at update.uu.se>
To: "Christos Papachristou" <chpap at ics.forth.gr>
Cc: <pups at minnie.tuhs.org>
Sent: Wednesday, February 26, 2003 3:04 PM
Subject: Re: [pups] (no subject)

> 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
> > 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 don't know ,it just says mem=158720

> > 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?
No. It wasn't a problem in speed, the default configuration for getty was
wrong (it was
configured for LA36 printer output). This is the first time I use a UNIX
that was meant for dialups with 110-9600 modems or terminals so please
excuse me. But I am learning... By the way
the console runs at 38.4kbps , but the gettys are internaly configured at
other speeds ,
the highest being 9.6kbps. Can't I use the full speed of the port?

> > Some information on the system. It is a KDJ11-B (M8190 -no suffix) i.e.
> > 11/84. So, the label on the system says microPDP11/73 (in an BA23
> > 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
> > 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
> > 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
> > 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
> > 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
> > 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

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