Probably time to move this to COFF, but
along the line of Fission for Program Comprehension....
I wonder how many of you don't know about Don Lancaster.
Pioneer in home computing back when that meant something, inventor of a
very low cost 1970s video terminal (the TV Typewriter), tremendously
skilled hacker, brilliant guy.
Also still alive, lives a couple hours away from me in Safford, AZ, and has
been doing fantastic research on Native American hanging canals for the
last couple decades.
Anyway: he wrote a magnificent piece on how to understand a (6502) program
from its disassembly, which reminded me of Gibbons's work:
https://www.tinaja.com/ebooks/tearing_rework.pdf
I don't think Don ever had a lot of crossover with the more academic world
of Unix people, but he's one of my heroes and I have learned a hell of a
lot from his works.
Adam
The ARPAnet reached four nodes on this day in 1969; at least one "history"
site reckoned the third node was connected in 1977 (and I'm still waiting
for a reply to my correction). Well, I can believe that perhaps there
were only three left by then...
According to my notes, the nodes were UCSB, UCLA, SRI, and Utah.
-- Dave
In keeping with the list charters, I'm moving this to COFF.
On Thursday, 2 December 2021 at 11:30:35 -0500, John Cowan wrote:
> On Thu, Dec 2, 2021 at 12:45 AM Henry Bent <henry.r.bent(a)gmail.com> wrote:
>
>> The Byte article (the scan of which I am very grateful for; not having to
>> go trawling through the stacks at the Oberlin College library is always a
>> plus) claims that the tools have been implemented on:
>>
>> Tandem
>
> That would be me; at least I registered it with Addison-Wesley,
> although someone else may have implemented it independently.
I recall something about this, but I didn't find very much in my
collection of old email messages. The most promising was:
Date: 87-11-06 09:47
From: LEHEY_GREG
To: ANDERSON_KEN @CTS
Subject: ?? Is there a "make"-like utility for Tandem ??
In Reply to: 87-11-05 18:59 FROM ANDERSON_KEN @CTS
3:?? Is there a "make"-like utility for Tandem ??
No, but I'd LOVE to have one. Ask Dick Thomas - in his spare time, he
converts software tools to Tandem.
Did you have contact with Dick?
Greg
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Moving to COFF as this is less UNIX and more computer architecture and
design style...
On Tue, Nov 30, 2021 at 3:07 AM <pbirkel(a)gmail.com> wrote:
> Given a random logic design it's efficient to organize the ISA encoding
> to maximize its regularity.
Probably also of some benefit to compilers in a memory-constrained
> environment?
>
To be honest, I think that the regularity of the instruction set is less
for the logic and more for the compiler. Around the time the 11 was being
created Bill Wulf and I think Gordan as co-author, wrote a paper about how
instruction set design, the regularity, lack of special cases, made it
easier to write a code optimizer. Remember a couple of former Bell and
Wulf students were heavily involved in the 11 (Strecker being the main one
I can think of off the top of my head).
Also remember that Gordan and the CMU types of those days were beginning to
create what we now call Hardware Description Languages (HDL). Gordon
describes in "Bell and Newell" (the definitive Computer Structures book of
the 1970s) his Processor-Memory-Switch (PMS) diagrams. The original 11
(which would become the 11/20) was first described as a set of PMS
diagrams. PMS of course, beget the Instruction Set Processor Language
(ISPL) that Mario created a couple of years later. While ISPL was after
the 11 had been designed, ISPL could synthesize a system using PDP-16 RTM
modules. A later version from our old friend from UNIX land, Ted Kowalski
[his PhD thesis actually], that could spit out TTL from the later ISPS
simulator and compiler [the S being simulation]. ISPS would beget VHDL,
which beget today Verilog/System Verilog.
IIRC it was a lecture Gordon Gordan gave us WRT to microcode *vs.* direct
logic. He offered that microcode had the advantage that you could more
easily update things in the field, but he also felt that if we could catch
the errors before you released the HW to the world, and if we could then
directly synthesize, that would be even better - no errors/no need to
update. That said, by the 11/40, DEC started to microcode the 11's,
although as you point out the 11/34 and later 11/44, where more direct
logic than the 11/40 - and of course Wulf would created the 11/40e - which
writeable control store so they add some instructions and eventually build
C.mmp.
Over to COFF...
On 2021-11-23 02:57, Henry Bent wrote:
> On Mon, 22 Nov 2021 at 21:31, Mary Ann Horton <mah(a)mhorton.net
> <mailto:mah@mhorton.net>> wrote:
>
> PL/I was my favorite mainframe programming language my last two
> years as
> an undergrad. I liked how it incorporated ideas from FORTRAN,
> ALGOL, and
> COBOL. My student job was to enhance a PL/I package for a History
> professor.
>
>
> What language were the PL/I compilers written in?
From AFIPS '69 (Fall): "The Multics compiler is the only PL/1 compiler
written in PL/1 [...]"
HOPL I has a talk on the early history of PL/1 (born as NPL) but nothing
on the question.
N.
>
> Wikipedia claims that IBM is still developing a PL/I compiler, which I
> suppose I have no reason to disbelieve, but I'm very curious as to who
> is using it and for what purpose.
>
> -Henry
Moving to COFF where this probably belongs because its less UNIX and more
PL oriented.
On Tue, Nov 23, 2021 at 3:00 AM Henry Bent <henry.r.bent(a)gmail.com> wrote:
> What language were the PL/I compilers written in?
>
I don't know about anyone else, but the VAX PL/1 front-end was bought by
DEC from Freiburghouse (??SP??) in Framingham, MA. It was written in PL/1
on a Multics system. The Front-end was the same one that Pr1me used
although Pr1me also bought their Fortran, which DEC did not. [FWIW: The
DEC/Intel Fortran Front-End was written in Pascal -- still is last time I
talked to the compiler folks].
I do not know what the Freiburghouse folks used for a compiler-compiler
(Steve or Doug might ), but >>I think<< it might not have used one.
Culter famously led the new backend for it and had to shuttle tapes from
MIT to ZKO in Nashua during the development. The backend was written in a
combination of PL/1, BLISS32 and Assembler. Once the compiler could self
host, everything moved to ZKO.
That compiler originally targeted VMS, but was moved to Unix/VAX at one
point as someone else pointed out.
When the new GEM compilers were about 10-15 years later, I was under the
impressions that the original Freiburghouse/Culter hacked front-end was
reworked to use the GEM backend system, as GEM used BLISS, and C for the
runtimes and a small amount of Assembler as needed for each ISA [And I
believe it continues to be the same from VSI folks today]. GEM based PL/1
was released on Alpha when I was still at DEC, and I believe that it was
released for Itanium a few years later [by Intel under contract to
Compaq/HP]. VSI has built a GEM based Intel*64 and is releasing/has
released VMS for same using it; I would suspect they moved PL/1 over also
[Their target customer is the traditional DEC VMS customer that still has
active applications and wants to run them on modern HW]. I'll have to ask
one of my former coworkers, who at one point was and I still think is, the
main compiler guy at VSI/resident GEM expert.
> Wikipedia claims that IBM is still developing a PL/I compiler, which I
> suppose I have no reason to disbelieve, but I'm very curious as to who is
> using it and for what purpose.
>
As best I can tell, commercial sites still use it for traditional code,
just like Cobol. It's interesting, Intel does neither but we spend a ton of
money on Fortran because so much development (both old and new) in the
scientific community requires it. I answered why elsewhere in more
detail: Where
is Fortran used these days
<https://www.quora.com/Where-is-Fortran-used-these-days/answers/87679712>
and Is Fortran still alive
<https://www.quora.com/Is-Fortran-still-alive/answer/Clem-Cole>
My >>guess<< is that PL/1 is suffering the same fate as Cobol, and fading
because the apps are being/have been slowly rewritten from custom code to
using COTS solutions from folks like Oracle, SAS, BAAN and the like. Not
so for Fortran and the reason is that the math has not changed. The core
of these codes is the same was it was in the 1960s/70s when they were
written. A friend of mine used to be the Chief Metallurgist for the US Gov
at NIST and as Dr. Fek put it so well: * "I have over 60 years worth of
data that we have classified and we understand what it is telling us. If
you magically gave me new code to do the same thing as what we do with our
processes that we have developed over the years, I would have to reclassify
all that data. It's just not economically interesting." *I personally
equate it to the QWERTY keyboard. Just not going to change. *i.e.* *"Simple
economics always beats sophisticated architecture."*
[-TUHS, +COFF]
On Tue, Nov 23, 2021 at 3:00 AM Henry Bent <henry.r.bent(a)gmail.com> wrote:
> On Mon, 22 Nov 2021 at 21:31, Mary Ann Horton <mah(a)mhorton.net> wrote:
>
>> PL/I was my favorite mainframe programming language my last two years as
>> an undergrad. I liked how it incorporated ideas from FORTRAN, ALGOL, and
>> COBOL. My student job was to enhance a PL/I package for a History
>> professor.
>>
>
> What language were the PL/I compilers written in?
>
The only PL/I compiler I have access to is, somewhat ironically, the
Multics PL/1 compiler. It is largely self-hosting; more details can be
found here: https://multicians.org/pl1.html (Note Doug's name appears
prominently.)
Wikipedia claims that IBM is still developing a PL/I compiler, which I
> suppose I have no reason to disbelieve, but I'm very curious as to who is
> using it and for what purpose.
>
I imagine most of it is legacy code in a mainframe environment, similarly
to COBOL. I can't imagine that many folks are considering new development
in PL/1 other than in retro/hobbyist environments and some mainframe shops
where there's a heavy existing PL/I investment.
- Dan C.
I recently had a discussion with some colleagues on the topic of
shells. Two people whom I respect both told me that Microsoft's
Powershell runs rings round the Bourne shell.
Somehow that sounds like anathema to me, but it's not beyond the
bounds of possibility. Before I waste time investigating, can anybody
here give me some insights?
Greg
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On Wed, Nov 17, 2021 at 3:24 PM Rob Pike <robpike(a)gmail.com> wrote:
> Perl certainly had its detractors, but for a few years there it was the
> lingua franca of system administration.
>
It's still what I reach for first when I need to write a state machine that
processes a file made up of lines with some--or some set of--structures.
The integration of regexps is far, far, far superior to what Python can do,
and I adore the while(<>) construct. Maintaining other people's Perl
usually sucks, but it's a very easy way to solve your own little problems.
Adam
