[Simh] [OT] What's the difference between the 1990 Brunner VAX Architecture book and the Leonard from 1987?

[lists at openmailbox.org]

Thank you so much. That's a wonderfully complete and very helpful answer.
I will save your email for future reference.

On Thu, 28 Jan 2016 12:04:17 -0500
Paul Koning <paulkoning at comcast.net> wrote:

> 
> > On Jan 28, 2016, at 5:28 AM, lists at openmailbox.org wrote:
> > 
> > Hi,
> > 
> > Since there are some ex-DEC people here and many people knowledgeable in
> > VAX can anybody tell me the [major] differences between these books if
> > any? The Brunner book is very expensive, the 1987 copy is very
> > affordable. What do I miss out on by buying the one by Timothy Leonard
> > from 1987?
> > 
> > I realize the scans are up on bitsavers but I usually find real books
> > easier to deal with.
> 
> I assume by "Brunner book" you mean the copy of DEC Std 032, the VAX
> Architecture Standard.  And "Leonard book" is the "VAX Architecture
> Reference Manual" edited by Tim Leonard, published by Digital Press.
> 
> Ok...  The DEC Std is a DEC internal document, labeled as such.  Some DEC
> standards were considered quite sensitive, and issued as numbered,
> individually-tracked documents.  I had one such for Alpha, which I duly
> returned to the document custodian when I left.
> 
> The DEC Std is the full, authoritative description of what a VAX is.  If
> you want to build a VAX (a new design, not a clone of an existing one),
> that document will tell you how to do so.  If you do everything it says,
> the result *should* be a correct VAX implementation, and VAX software
> should run on it.  
> 
> (This is the "conformance implies interoperability" principle of standard
> design.  This was the definition of proper standards design that was used
> at DEC.  For example, if you want to implement DDCMP, all you have to do
> is carefully code what the DDCMP spec say, and if you do so, it WILL
> work.   Unfortunately, most of the rest of the world does not believe in
> this level of quality.  I was involved at one point in IETF standards
> work, and I mentioned this principle in a meeting.  The document editor
> actually objected to what I said and stated that it was unreasonable to
> expect protocol standards to do this.  And sure enough, the document he
> produced is NOT good enough that you can just do what it says and expect
> the result to be a working implementation -- you have to hack on it and
> test against other implementations to come up with the right combination
> of hacks and tweaks and bug workarounds for things to work.  Sigh.)
> 
> On the other hand, the Digital Press book is a public document.  Its
> purpose is to describe to VAX *users* what a VAX is.  If you want to port
> an OS, or a compiler, to VAX, you'll want this book.  If you want to
> write applications for VAX, it will certainly work as well (though it
> might be more than you need).
> 
> In other words, the book is a subset of the DEC Std.  If you want the
> ultimate reference, grab the standard.  If you want to debug an emulation
> (say, if there is debate about whether SIMH gets the VAX correct), the
> DEC Std will be the authority to settle the question. For other software
> work -- say, the NetBSD port for VAX, or the VAX backend of GCC -- the
> published book is likely to be sufficient.
> 
> 	paul
> 
> _______________________________________________
> Simh mailing list
> Simh at trailing-edge.com
> http://mailman.trailing-edge.com/mailman/listinfo/simh

-- 
Please do not copy me on mailing list replies. I read the mailing list.
RSA 4096 fingerprint 7940 3F02 16D3 AFEE F2F8  ACAA 557C 4B36 98E4 4D49