[Beowulf] Fortran is Awesome

John Hearns hearnsj at googlemail.com
Mon Dec 3 22:39:41 PST 2018


Jim, wow!
Talking about operating systems, and requirements for real time responses
etc etc. my own history of OSes is pretty wide too.
For work at CERN VM/CMS and MVS for processing of tape jobs, then VAX VMS
to run on the clusters my experiment had.
VMS clustered pretty easily, but there is a limit of 128 machines in a
cluster, so we had several analysis clusters in the data centre.
We (ALEPH) ended up going with the DEC ALPHA processors in new clusters.
My lab in Glasgow has Apollo Domain OS workstations too - which were
powerful and pretty funky.

The truth is that Unix was for longhairs and computer science types. One of
the LEP experiments, L3, did use a bunch of SGI MIPS machines though.
For technical and commercial computing the great hope was Windows NT. It
was going to run everywhere - from weedy desktop microprocessors, up to DEC
ALPHAS in big clusters and on MIPS systems. One ring to rule them all.
And remember that Dave Cutler from DEC was hired by Microsoft   VMS --> WNT
by one character shift.

But it was not meant to be. If I'm not wrong Microsoft killed the MIPS port
and went after the commercial market.
We saw thew rise of the Unix system - partly because the first web servers
were ported to the DEC Unix operating system (I cant remember what the
exact name was) and Solaris and these seemed to be the natural environment
for early web servers.

And then Jon Maddog Hall organised the gift of a DEC ALPHA system to a
bright young lad in Finland who was workign on a hobby project. The rest is
history.

















On Tue, 4 Dec 2018 at 03:05, Lux, Jim (337K) via Beowulf <
beowulf at beowulf.org> wrote:

>
>
> Jim Lux
> (818)354-2075 (office)
> (818)395-2714 (cell)
>
>
> -----Original Message-----
> From: Beowulf [mailto:beowulf-bounces at beowulf.org] On Behalf Of Robert G.
> Brown
> Sent: Friday, November 30, 2018 9:35 AM
> To: Paul Edmon <pedmon at cfa.harvard.edu>
> Cc: beowulf at beowulf.org
> Subject: Re: [Beowulf] Fortran is Awesome
>
> On Thu, 29 Nov 2018, Paul Edmon wrote:
>
> >
> > Not necessarily.? I learned Fortran as part of my Numerical Methods
> > for Physicists in grad school.? We had the option of using C or
> > Fortran.? Fortran has proved much more useful to learn than C and I've
> picked up C on the side.?
> > In many cases programming is a matter of logical structured thinking,
> > if you can get that the rest is learning syntax for different languages.
> >
> > For people doing numerical methods, Fortran is way superior in terms
> > of usability than C.? That said I would never teach Fortran in a
> > Computer Science class, but in a Numerical Methods for Scientists I
> would go with Fortran.
>
> That's similar to my own experience, actually -- I learned PL/1 (gasp, I
> know:-) in my first programming course, used it in my second course
> (writing an assembler emulator and compiler emulator in PL/1 was
> entertaining), and the only other course I took in programming of any sort
> was Numerical Methods, and Learned Fortran IV (and how to do e.g.
> quadrature and lots more) in that course.  For a long while all of my
> actual programming was in F-IV as that's what the IBM 360/370 would run and
> it let me use at least some of the stuff from our textbook as well as a
> couple of other big books filled with F-IV numerical code, but in the end I
> wrote a ton myself.  I literally filled a box with cards writing a
> complicated angular momentum coupling code for nuclear scattering
> experiments -- two ways, one of them a short form derived by my employer,
> one of them brute force -- to verify that his derivation was correct within
> a single phase error.
>
> BUT, F-IV's I/O sucked.  Really.  Hollerith?  The branching sucked.  The
> line requirements (designed for first cards, then TTY lines) sucked.
> The character data handling in general sucked.  Its conditionals were
> comparatively primitive.  I continued using it across getting into grad
> school and writing my dissertation and programming my dissertation, but
> somewhere in the mid-late 80's I started really using PCs big time, as they
> got to where I could actually run SOME stuff on them instead of expensive,
> expensive mainframes or the department's expensive, expensive mini
>
>
>
> ... and that's sort of the thing.. I spent most of my early professional
> career writing software in Fortran that had no business being written in
> Fortran, but that's what was available. Late 70s, early 80s.
>
> The US Navy's  aircraft routing system (OPARS)  - not a lot of numerical
> computation, but lots of graph handling and implementation of the A*
> minimum path algorithm.  Why yes, you CAN implement linked lists and
> pointers in Fortran arrays.  That and interpolation into gridded weather
> products of one sort or another.  That ran on a big CDC-7600 used to run
> numerical weather models.
> No C language there.
>
> The Los Angeles Police Department's computer dispatch system (ECCCS) was
> written in Fortran - because that's what was available on the PDP 11/70
> running RSX-11M in a 4 processor multiprocessor configuration (shared
> address space using PCL-11B, and dual ported peripherals)
>
> Not a lot of arithmetic, almost all text management, device management,
> and databases - yes folks, we wrote a B-tree database system running on
> dual port disk drives with automatic shadowing and hot standby failover. We
> wrote what are essentially device drivers to format messages in BiSync to
> send and receive from the in-car terminals. Hard real time with millisecond
> kinds of response requirements to sendi coded messages via serial ports to
> remote radio receivers to switch channels and audio streams. (Incoming 911
> call assigned by dispatcher to operator 37 and the audio needs to follow)
> And a whole room full of PDT-11s (which are basically a VT100 with a LSI-11
> inside)
>
> So while there was a C compiler for the PDP-11, it wasn't available for
> RSX-11M in 1979.  I doubt they would have run a mission critical system on
> Unix back then.
>
> I just found this:
>  ! DECUSC.HLP   Created by Martin Minow, 25-Jul-80, edited 11-Feb-82
> !
> 1 C Decus C is a PDP-11 compiler for the C language.  It is distributed
> by Decus and is otherwise unsupported.  It may be used under RSX11-M,
> RSTS/E, RT11, and VAX/VMS (compatibility mode).  The language
> is generally as described in Kernighan and Ritchie's book, The
> C Programming Language (with several restrictions).
>
> Key phrases "unsupported" and "generally as described"
>
> I wrote an assembler for a one-off bitslice processor based on the AM2901
> in Fortran (running on PRIMOS from Prime computers)  Fun fact, the
> operating system was written in Fortran IV, with just a bit of Assembler.
> Not only that, but the PRIME CPU design was tailored to Fortran and had a
> single instruction to do the 3 way Fortran branch.  Take that Burroughs,
> with your Algol based CPU.  (although I really liked the Burroughs big
> machine design - made specifically for high level languages, reentrancy
> without pain, multiple stacks, blindingly fast compilers)
>
> I don’t recall seeing significant C in the "non-academic" world,
> especially in PCs until the mid-late 80s  - compilers cost too much, etc.
> I think I actually wrote code in Ada on a IBM PC before I wrote code in C
> (thanks to a discount non-conforming Ada compiler called Janus)- and plenty
> of Fortran, Basic and Pascal.  Of course, I was running Fortran on a Z80
> machine in 1977, too.
>
> A friend of mine was doing development in C on a 68000 based machine in
> the mid 80s.
>
>
> TL;DR  - You can do amazing things in Fortran, and for a good part of
> computing history, it was the Fortran compiler that was first compiler
> released and supported by the mfr, probably because of significant
> government funding for computational work that is Fortran's forte.
> Numerical simulations of shock waves, weather, particle transport, etc.
>
>
>
>
>
>
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