Re: [TUHS] In Memoriam: Per Brinch Hansen

Re: [TUHS] In Memoriam: Per Brinch Hansen

[Doug McIlroy]

A tangential connection to early Unix experience:

My collection of early computer manuals includes Brinch Hansen's manual
for the RC 4000, which stands out for its precise description of the
CPU logic--in Algol 60! It's the only manual I have seen that offers a
good-to-the-last-bit formal description of the hardware.

DEC presented something of the sort for the PDP-11, but punted where
the woods got thick. When I wanted to know how they computed the last
bit of floating-point results, I got no satisfaction. Amidst a thorough
description of addressing came this formulation of the actual computation:
"form floating point result".

Doug

Re: [TUHS] In Memoriam: Per Brinch Hansen

[Ben Greenfield via TUHS]

Is this a weblink to that manual?

I want to read something so well written:)

Ben

https://pdfs.semanticscholar.org/b77f/02dedb784a52229c5376277173c5ef6da5c1.pdf

> On Aug 2, 2018, at 8:44 AM, Doug McIlroy <doug@cs.dartmouth.edu> wrote:
> 
> A tangential connection to early Unix experience:
> 
> My collection of early computer manuals includes Brinch Hansen's manual
> for the RC 4000, which stands out for its precise description of the
> CPU logic--in Algol 60! It's the only manual I have seen that offers a
> good-to-the-last-bit formal description of the hardware.
> 
> DEC presented something of the sort for the PDP-11, but punted where
> the woods got thick. When I wanted to know how they computed the last
> bit of floating-point results, I got no satisfaction. Amidst a thorough
> description of addressing came this formulation of the actual computation:
> "form floating point result".
> 
> Doug

Re: [TUHS] In Memoriam: Per Brinch Hansen

[Larry McVoy]

I suspect not, I suspect his first reference is the one you want.

On Thu, Aug 02, 2018 at 09:10:54AM -0400, Ben Greenfield via TUHS wrote:
> Is this a weblink to that manual?
> 
> I want to read something so well written:)
> 
> Ben
> 
> https://pdfs.semanticscholar.org/b77f/02dedb784a52229c5376277173c5ef6da5c1.pdf
> 
> > On Aug 2, 2018, at 8:44 AM, Doug McIlroy <doug@cs.dartmouth.edu> wrote:
> > 
> > A tangential connection to early Unix experience:
> > 
> > My collection of early computer manuals includes Brinch Hansen's manual
> > for the RC 4000, which stands out for its precise description of the
> > CPU logic--in Algol 60! It's the only manual I have seen that offers a
> > good-to-the-last-bit formal description of the hardware.
> > 
> > DEC presented something of the sort for the PDP-11, but punted where
> > the woods got thick. When I wanted to know how they computed the last
> > bit of floating-point results, I got no satisfaction. Amidst a thorough
> > description of addressing came this formulation of the actual computation:
> > "form floating point result".
> > 
> > Doug

-- 
---
Larry McVoy            	     lm at mcvoy.com             http://www.mcvoy.com/lm 

Re: [TUHS] In Memoriam: Per Brinch Hansen

[Bakul Shah]

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I think it is this one: http://bitsavers.org/pdf/regnecentralen/RC_4000_Reference_Manual_Jun69.pdf

Along these lines, at least one of Fujitsu’s high end network switches was described using PowerPoint slides. At one point while working for them I felt a software simulator of the switch would really help with testing switch software. So I started developing one on my own. That is when I discovered these slides were not only very detailed but also very accurate and quite clear. They answered every question I had during the development. I have never seen such /engineering/ use of PowerPoint anywhere else.

> On Aug 2, 2018, at 7:07 AM, Larry McVoy <lm@mcvoy.com> wrote:
> 
> I suspect not, I suspect his first reference is the one you want.
> 
>> On Thu, Aug 02, 2018 at 09:10:54AM -0400, Ben Greenfield via TUHS wrote:
>> Is this a weblink to that manual?
>> 
>> I want to read something so well written:)
>> 
>> Ben
>> 
>> https://pdfs.semanticscholar.org/b77f/02dedb784a52229c5376277173c5ef6da5c1.pdf
>> 
>>> On Aug 2, 2018, at 8:44 AM, Doug McIlroy <doug@cs.dartmouth.edu> wrote:
>>> 
>>> A tangential connection to early Unix experience:
>>> 
>>> My collection of early computer manuals includes Brinch Hansen's manual
>>> for the RC 4000, which stands out for its precise description of the
>>> CPU logic--in Algol 60! It's the only manual I have seen that offers a
>>> good-to-the-last-bit formal description of the hardware.
>>> 
>>> DEC presented something of the sort for the PDP-11, but punted where
>>> the woods got thick. When I wanted to know how they computed the last
>>> bit of floating-point results, I got no satisfaction. Amidst a thorough
>>> description of addressing came this formulation of the actual computation:
>>> "form floating point result".
>>> 
>>> Doug
> 
> -- 
> ---
> Larry McVoy                     lm at mcvoy.com             http://www.mcvoy.com/lm 

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Re: [TUHS] In Memoriam: Per Brinch Hansen

[Perry E. Metzger]

On Thu, 02 Aug 2018 08:44:56 -0400 Doug McIlroy
<doug@cs.dartmouth.edu> wrote:
> A tangential connection to early Unix experience:
> 
> My collection of early computer manuals includes Brinch Hansen's
> manual for the RC 4000, which stands out for its precise
> description of the CPU logic--in Algol 60! It's the only manual I
> have seen that offers a good-to-the-last-bit formal description of
> the hardware.
> 
> DEC presented something of the sort for the PDP-11, but punted where
> the woods got thick. When I wanted to know how they computed the
> last bit of floating-point results, I got no satisfaction. Amidst a
> thorough description of addressing came this formulation of the
> actual computation: "form floating point result".

For those that are familiar with the RISC V architecture, there's a
formal specification of the architecture that was done in a system
built on Coq, and also a fully formally verified translation of the
specification into RTL. (The spec didn't include floating point as of
about a year ago but it may by now.)

A good overview of the system involved is here:

http://plv.csail.mit.edu/kami/papers/icfp17.pdf

Followups might belong on the coff list, not sure.

Perry
-- 
Perry E. Metzger		perry@piermont.com

[TUHS] In Memoriam: Per Brinch Hansen

[Dave Horsfall]

[ I've always posted these to TUHS with no objections, so I have no idea 
whether COFF would be a better forum; feel free to spank me (I might 
even enjoy it!) ]

We lost Per Brinch Hansen, a computer scientist, on this day in 2007.  He 
specialised in operating systems and concurrent programming, and wrote the 
classic book "Operating System Principles" which was published in six 
languages for decades.  He also wrote another book "The Architecture of 
Concurrent Programs" which demonstrated an entire operating system written 
in Concurrent Pascal (much like the Lions' books on Unix).

-- Dave

Re: [TUHS] In Memoriam: Per Brinch Hansen

[Toby Thain]

On 2018-07-30 8:40 PM, Dave Horsfall wrote:
> [ I've always posted these to TUHS with no objections, so I have no idea
> whether COFF would be a better forum; feel free to spank me (I might
> even enjoy it!) ]
> 
> We lost Per Brinch Hansen, a computer scientist, on this day in 2007. 
> He specialised in operating systems and concurrent programming, and
> wrote the classic book "Operating System Principles" which was published
> in six languages for decades.  He also wrote another book "The
> Architecture of Concurrent Programs" which demonstrated an entire
> operating system written in Concurrent Pascal (much like the Lions'
> books on Unix).

His anthology "Classic Operating Systems" is also an informative read
and I think can be found online.

--Toby

> 
> -- Dave
> 

Re: [TUHS] In Memoriam: Per Brinch Hansen

[Wesley Parish]

I've got his Operating System Principles  and The Architecture of
Concurrent Programs. I've seen his Programming a Personal Computer -
about the Edison dialect of Pascal as a systems programming language,
an offshoot of Concurrent Pascal, iirc.

I'm slightly amused by his statement published in the Wikipedia
article on him, :

"There, his first significant project was writing a parser for a COBOL
compiler for the Siemens 3003 computer. Subsequently, he wrote a file
system to be used during execution of the compiled COBOL programs,
later observing "I now understand that it was really a small operating
system, I had programmed. However, in the mid 1960s, the dividing line
between language implementation and operating systems was still not
clearly understood."[ "

Which is quite an understatement - it is probably one of the reasons
why Prof Lions considered Solo unsuitable as a general purpose OS for
students to work with and work on. It would not be impossible to
develop a non-Pascal-based OS on the Concurrent Pascal microkernel,
but I don't get the impression that he had planned for it.

http://pascal.hansotten.com/per-brinch-hansen/ is a good site about him.

Wesley Parish

On 7/31/18, Toby Thain <toby@telegraphics.com.au> wrote:
> On 2018-07-30 8:40 PM, Dave Horsfall wrote:
>> [ I've always posted these to TUHS with no objections, so I have no idea
>> whether COFF would be a better forum; feel free to spank me (I might
>> even enjoy it!) ]
>>
>> We lost Per Brinch Hansen, a computer scientist, on this day in 2007.
>> He specialised in operating systems and concurrent programming, and
>> wrote the classic book "Operating System Principles" which was published
>> in six languages for decades.  He also wrote another book "The
>> Architecture of Concurrent Programs" which demonstrated an entire
>> operating system written in Concurrent Pascal (much like the Lions'
>> books on Unix).
>
> His anthology "Classic Operating Systems" is also an informative read
> and I think can be found online.
>
> --Toby
>
>>
>> -- Dave
>>
>
>