[Simh] Getting to the 780 console prompt

[Robert Jarratt]

> -----Original Message-----
> From: simh-bounces at trailing-edge.com [mailto:simh-bounces at trailing-
> edge.com] On Behalf Of Stephen Hoffman
> Sent: 24 April 2009 18:07
> To: simh at trailing-edge.com
> Subject: Re: [Simh] Getting to the 780 console prompt
> 
> Robert Jarrett wrote
> 
> On Thu, 23 Apr 2009 18:26:54 +0100, Robert Jarratt wrote:
> 
> > OK, I understand that the diagnostics would not work, but I have
> > been trying
> > to modify R5 using the SIMH DEPOSIT command before booting the 780
> > to see if
> > I can get it do a conversational boot (R5=1) or anything else. It
> > does not
> > seem to react to any R5 values, except 0x10 which seems to cause
> > some sort
> > of hang. Should I expect it to do a conversational boot if I try
> > this (DEP
> > R5 1)?
> 
> Can we start with what problem you're trying to solve here, and not
> with a proposed solution and the ensuing discussion?   And I don't
> mean the literal "boot the diagnostic supervisor" by this.
> 

The reason I want to run diagnostics is because I am playing around with an
attempt to add a device to the 780 emulation and I want to see what happens
when something tries to use the device. I have very little experience of so
many things at this level that I am finding it a bit of a struggle just to
get anything to happen, and getting diagnostics to work might just provide
me with a bit more info.

I have since been made aware that SIMH will accept a command like BOOT
RQ0/R5:10 (I did not know this until now), this works whereas depositing 10
in R5 and the booting does not. So I can boot the diagnostics, but it now
looks as if I am missing some files. Nevertheless I have now also been told
that there are some diagnostics that will run under VMS as well, so for now
it looks like I don't need the standalone diagnostics.


> Some background and some pointers...
> 
> With a typical VAX, depositing 10 into register R5 prior to loading
> and launching VMB causes the VMB image (whether embedded in the
> console ROM, or loaded from the console media, or loaded from the
> system disk, or files that are referenced by the simh FLOAD from the
> RX01 console floppy image) to go look in the file
> SYSMAINT]DIAGBOOT.EXE as the secondary bootstrap, which launches the
> Diagnostic Supervisor (DS).  Some boxes can network boot DS, and many
> can boot DS from tape media.

Indeed that is what I had been trying, just going the wrong way about it as
mentioned above.

> 
> The available VAX boot flags are (also) available via the site
> http://www.hoffmanlabs.com/vmsfaq
>   (also at http://labs.hoffmanlabs.com/node/1) and that site has a
> "newer" edition of the OpenVMS FAQ than what's posted at HP, or you
> can snag the "newer" edition off of Freeware V8.0.  You can download a
> PDF or other formats from the HoffmanLabs web site, as well.
> 
> Most (recent) OpenVMS VAX releases have a tool known as EXCHANGE,
> which can access the RT console media.  That tool is underneath
> CONSCOPY.COM on various OpenVMS VAX versions, and how you managed the
> VAX RX01 media with OpenVMS.  IIRC, EXCHANGE arrived around V4.0 or
> so.  (Prior to that, the RSX tools and MCR tended to be used.  PIP?
> It's been a very long while since I tried RX01 console access from
> V3.x...)
> 
> The VAX-11/780 console worked from boot command files and not from
> anything resembling a console prompt; the LSI-11 was good for its time
> but is now very limited.  With the VAX-11/780, there was usually a
> DSBOO.CMD or some such set up on the console storage device for this;
> you'd usually end up editing DEFBOO.CMD to do what you need, and
> create SYFBOO.CMD or DSBOO.CMD or some such local name.   This
> involved using EXCHANGE or CONSCOPY, too.  With the simh emulation,
> the console is rather different than that of a "real" VAX-11/780 box.
> You've probably already found the documentation at
> http://simh.trailing-edge.com/pdf/vax780_doc.pdf
>   document, but that points to the use of the (far more recent)
> MicroVAX-style console with the simulator.  Which means BOOT dev /
> R5:10 is the usual command to (try to) get the DS going here on the
> VAX-11/780 emulation.
> 
> There's a copy of the VAX-11/780 diagnostic supervisor manual at MANX
> at http://vt100.net/mirror/hcps/ds780ug2.pdf for reference, though
> there needs to be some recognition of the presence of the emulation
> and not real hardware.  There are various other VAX diagnostic-related
> documents posted on MANX, too.
> 
> Finding out whether DS passes simh and simh hardware is certainly
> interesting, but few folks are looking to verify the simulator.  And
> those that are hopefully have access to the AXE (and MAX) VAX
> architecture verification tools; those are the old DEC tools for
> verifying a VAX processor and its instruction set.  AXE (and MAX)
> doesn't do all that much for verifying the I/O and the system
> environment.  (I don't know if Bob S. or Tim S. ever got his hands on
> these tools.)
> 
> Getting various versions of (as it was then known) VAX/VMS to boot on
> the VAX-11/780 also depends on the particular implementation of the
> simulator, too.  IIRC, you needed V3.0 to be able to boot with C-
> series MS780 memory, for instance.  There were various hardware and
> version inter-dependencies lurking back in that era; it was quite
> common to need a specific new VMS release for a specific hardware
> giblet.   For the 20th anniversary, Andy G. and I and other folks
> tried to scrounge up and put together a VAX-11/780 that could boot
> V1.0, but we couldn't get the right (working) pieces.  (And some folks
> chucked some what we had acquired, but that's another story.)
> 
> But (my) real question here is around what you're up to here; why
> you're looking to launch the DS.  Whether this is a hobbyist interest,
> or a production-level server migration question at its kernel.  The
> answer to this can take the discussion in a number of different
> directions.
> 
> 


Definitely, this is a hobbyist only interest.

> 
> 
> 
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