[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[Noel Chiappa via TUHS]

    > From: Charles H Sauer

    > For various reasons, lack of commercial dominance, lack of source, ...,
    > there didn't seem to be any specific OS that gained mind share in the
    > O.S. community until Unix did.

Before UNIX, almost all OS's were written in assembler, tying them to one
particular vendor's machines. (Multics, although in PL/I, was so specialized
to the Heneywell architecture it was in the same boat.) UNIX was really the
first portable OS (at least, that I know of - am I wrong?. I suspect thatwas
a large factor too.

	Noel

[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[Charles H Sauer (he/him) via TUHS]

On 9/19/2025 4:49 PM, Noel Chiappa wrote:
>      > From: Charles H Sauer
> 
>      > For various reasons, lack of commercial dominance, lack of source, ...,
>      > there didn't seem to be any specific OS that gained mind share in the
>      > O.S. community until Unix did.
> 
> Before UNIX, almost all OS's were written in assembler, tying them to one
> particular vendor's machines. (Multics, although in PL/I, was so specialized
> to the Heneywell architecture it was in the same boat.) UNIX was really the
> first portable OS (at least, that I know of - am I wrong?. I suspect thatwas
> a large factor too.
> 
> 	Noel

Emphasis on "portable," since there seemed to be so many competing 
processor architectures. Charlie
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[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[John Levine via TUHS]

It appears that Charles H Sauer (he/him) via TUHS <sauer@technologists.com> said:
>> Before UNIX, almost all OS's were written in assembler, ...
>
>Emphasis on "portable," since there seemed to be so many competing 
>processor architectures. Charlie

Yup. Until the late 1960s computers had such widely different addressing and
data architectures that it wouldn't have made sense to try to write portable
system software. FORTRAN and COBOL programs could be fairly portable, but at a
much higher level of abstraction than an operating system.

But S/360 became the de facto standord for mainframes, and a few years later the
PDP-11 was successful enough as a mini that the only data format that mattered
was twos-complement binary, and the only addressing was 8 bit bytes.

That made portability a lot easier.  The only attempt I know to put Unix on a machine
that didn't have 8-bit bytes was the BBN C70 with 10-bit bytes.  One of the programmers
told me that finding all the 8-bit assumptions in Unix applications was very painful.

R's,
John

[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[Niklas Karlsson via TUHS]

Den sön 21 sep. 2025 kl 03:13 skrev John Levine via TUHS <tuhs@tuhs.org>:

> That made portability a lot easier.  The only attempt I know to put Unix
> on a machine
> that didn't have 8-bit bytes was the BBN C70 with 10-bit bytes.  One of
> the programmers
> told me that finding all the 8-bit assumptions in Unix applications was
> very painful.
>

I had been under the impression that there was a NetBSD port to the PDP-10,
but apparently it has only been proposed.

Niklas

[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[Lars Brinkhoff via TUHS]

Niklas Karlsson wrote:
> I had been under the impression that there was a NetBSD port to the
> PDP-10, but apparently it has only been proposed.

It was started but didn't get very far.  First it used GCC, later PCC.

[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[Phillip Harbison via TUHS]

John Levine via TUHS wrote:
> Yup. Until the late 1960s computers had such widely different addressing and
> data architectures that it wouldn't have made sense to try to write portable
> system software. FORTRAN and COBOL programs could be fairly portable, but at a
> much higher level of abstraction than an operating system.
> ...
> The only attempt I know to put Unix on a machine that didn't have 8-bit
 > bytes was the BBN C70 with 10-bit bytes.  One of the programmers told
 > me that finding all the 8-bit assumptions in Unix applications was
 > very painful.

UNIVAC 1100 says hi.
- 36-bit general purpose A(ccumulator) registers.
- 36-bit and 72-bit floating point
- indeX registers split into 18-bit address (because who would ever
   need to address more than 256K words?) and 18-bit auto-increment
- 6-bit characters (Fieldata). ASCII support added later with 9-bit
   characters (not sure how they used thew extra bit)
- octal preferred here ;)

UAH had been a Univac shop since beginning with NASA and US Army
leftovers. This is probably why UAH waited until Sperry remarketed
the Computer Consoles Power 6 (aka Tahoe, not to be confused with
IBM Power 6). I installed UNIX, my homegrown clone of Emacs, and set
up netnews on our first UNIX system (uahcs1). I was not an employee,
just a proud alumnus and friend of the CS department chairman.

Meanwhile I was running Unisoft's port of UNIX System V.0 on my home-
built 68000 box with a mere 1 MB of memory and no demand paging hence
the need for my own mini-clone of Emacs (more like MINCE) that loaded
as fast as vi. It was dubbed "madhat" and was the first public access
netnews host in The Rocket City with a free news feed compliments of
Lindsey Cleveland at AT&T Atlanta Cable Works (akgua) until I migrated
the feed to uahcs1.

I worked on other 68K systems, both UNIX and embedded, but they were
all programmed in C. It was not much of a challenge once you made sure
your homegrown malloc (for embedded) always returned a long-aligned
block of memory. A coworker had tested his malloc on an NS16032 and
was confused when he got Address Error traps. He tried to convince
management that the 68000 was broken. While the MS16032 supported
unaligned access it did so at a huge performance penalty.

Our compiler (Green Hills) took care of other alignment issues as
long as your malloc behaved.

It helped if you used unsigned chars since the 68K MOVE instruction
did not sign-extend and required two instructions (EXT.W and EXT.L)
to extend to 32 bits. The 68010 and later 680x0 family added EXT.B
(extend byte to long word) but if you rolled your own libraries (for
embedded) why not avoid sign extension entirely?

-- 
Phil Harbison

[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[Phillip Harbison via TUHS]

Phillip Harbison via TUHS wrote:
> While the MS16032 supported unaligned access it did so at a huge
 > performance penalty.

NS, as in National Semiconductor, not MS.

-- 
Phil Harbison

[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[Lars Brinkhoff via TUHS]

Phillip Harbison wrote:
> UNIVAC 1100 says hi.
> - 36-bit general purpose A(ccumulator) registers.
> - 36-bit and 72-bit floating point
> - indeX registers split into 18-bit address (because who would ever
>   need to address more than 256K words?) and 18-bit auto-increment
> - 6-bit characters (Fieldata). ASCII support added later with 9-bit
>   characters (not sure how they used thew extra bit)
> - octal preferred here ;)

And for yet more fun, one's complement.  After having worked on a PDP-10
backend for GCC, I looked into this one.  But it never went anywhere.

[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[Phillip Harbison via TUHS]

Lars Brinkhoff via TUHS wrote:
> Phillip Harbison wrote:
>> UNIVAC 1100 says hi.
>> - 36-bit general purpose A(ccumulator) registers.
>> ...
> 
> And for yet more fun, one's complement.  After having worked on a PDP-10
> backend for GCC, I looked into this one.  But it never went anywhere.

Oh! I forgot about that. I should have remembered the long discussion
about binary math in 1st quarter 1100 assembler.

During the space race plus early Army missile development they built
Research Institute (now Von Braun Hall) where Sperry set up a trio
of 1108 systems. When Sperry got out of the time sharing business due
to some court decision, the Army took one, NASA took one, and UAH got
one. Not sure if the 1108 was donated but the building was and became
home to UAH school of engineering. The 1108 memory was upgraded from
core to semiconductor which I think makes it an 1100/10. That's how
we got stuck with Univac.

-- 
Phil Harbison

[TUHS] Re: [COFF] SOSP 1973 [was Multics<->Unix Re: Re: History of cal(1)?

[Dave Horsfall via TUHS]

On Mon, 22 Sep 2025, Lars Brinkhoff via TUHS wrote:

> And for yet more fun, one's complement.  After having worked on a PDP-10 
> backend for GCC, I looked into this one.  But it never went anywhere.

Hey, what's wrong with negative zero?

-- Dave, who used to program on a Cyber 72