Tommy Flowers MBE was born on this day in 1905; amongst other things he
designed Colossus, the world's first programmable electronic computer,
which was used to break the German Lorenz cipher (not Enigma, as some
think).
Relevance to Unix? Well, without the world's first usable computer we
would not have the world's first usable OS, and M$ would probably reign
supreme by now...
--
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will suffer."
> More here:
> http://minnie.tuhs.org/pipermail/tuhs/2014-October/005218.html
Which sez:
There is a second document, untitled, no date, which I have not been able to
locate online at all.
..
From the content, it seems to be from shortly after the previous one, so say,
circa 1977.
I poked around in a dump of the CSR Unix which I now have available to me, and
found a copy of it. I just checked the Internet (using the canonical search
engine) for various phrases from it, but I still could not turn it up. So,
here it is in machine-readable form:
http://ana-3.lcs.mit.edu/~jnc/history/unix/CChanges.txt
Hope this is some use to someone... :-)
Noel
Amusing, I don't think I ever heard the appellation "phototypesetter C"
before. Certainly C and the phottypesetter developed independently, though
in the same room. But the explanation that they got linked by appearing
in the same tape release makes perfect sense. Thanks for the tidbit.
Doug
> From: "Ron Natalie"
> At some point .. and the ability to assign/pass structures got
> supported, though I thought that was the compiler that came with V7.
That is my vague recollection too.
> I'm still annoyed they didn't fix arrays when they fixed structs.
Which aspect? The ability to assign/pass/return arrays, or the funky way that
array naming worked (I'm trying to remember the details, I think it was
something to do with 'arrays' passed as arguments - it was actually a pointer
that was passed, but the declaration didn't have to say 'pointer').
Noel
> From: Tony Finch
> when did C get its cast operator?
Well after that piece of code was written! :-)
I don't recall exactly off the top of my head, but I recall 2-3 notes to
users about the evolution of C post 'vanilla' V6; I think a lot of it was
related to work being done on typetting stuff, hence the moniker
'phototypsetter compiler' which was applied to that 'improved' C.
One of the notes is fairly common, but another I have only in hardcopy
(although I scanned it at one point).
I'll try and turn all of them, along with some notes I made about the
differences between 'vanilla' V6 C and 'phototypsetter C' (which a lot of the
later V6 users started with - I certainly did), into an article on the
Computer History wiki on the early evolution of C.
Noel
PS:
> I recall 2-3 notes to users about the evolution of C post 'vanilla' V6
> ...
> One of the notes is fairly common, but another I have only in hardcopy
> (although I scanned it at one point).
More here:
http://minnie.tuhs.org/pipermail/tuhs/2014-October/005218.html
If anyone knows of any other documentation of C evolution, I'd be interested
in hearing about it for the Computer History wiki page.
Noel
> From: "Steve Johnson"
> The number on the left is a PDP-11 address, probably for some kind of
> control register.
It's the Processor Status Word, which contained the CPU's hardware priority
level, condition codes, etc.
> That's a construction that's left over from B.
I wonder why it was written as "0177776->integ", rather than "*017776"?
Probably the former allowed the C compiler to work out what size the operand
was. (BTW, 'integ' was declared in a structure declaration as follows:
struct {
int integ;
};
(Did the code looked at actually say "0177776->int"? The compiler might have
barfed on a reserved keyword being used like that.)
Noel
Has anyone got a setup where they can run something like nm(1) on the
compiled Third Edition Unix C files and send me the output?
(Alternatively, just send me the .o files, and I'll whip up something to
read their symbols.) I tried to compile the source code on a modern
system by hacking old C to something closer to what GCC will accept,
with commands such as the following.
cc -E dp.c |
sed 's/=\([&|+-]\)/\1=/g;s/struct[ \t]*(/struct {/' |
gcc -w -x c -
However, I stumbled on the use of structure fields on things that aren't
structures, e.g. "0177776->int =| 300"
It has often been told how the Bell Labs law department became the
first non-research department to use Unix, displacing a newly acquired
stand-alone word-processing system that fell short of the department's
hopes because it couldn't number the lines on patent applications,
as USPTO required. When Joe Ossanna heard of this, he told them about
roff and promised to give it line-numbering capability the next day.
They tried it and were hooked. Patent secretaries became remote
members of the fellowship of the Unix lab. In due time the law
department got its own machine.
Less well known is how Unix made it into the head office of AT&T. It
seems that the CEO, Charlie Brown, did not like to be seen wearing
glasses when he read speeches. Somehow his PR assistant learned of
the CAT phototypesetter in the Unix lab and asked whether it might be
possible to use it to produce scripts in large type. Of course it was.
As connections to the top never hurt, the CEO's office was welcomed
as another ouside user. The cost--occasionally having to develop film
for the final copy of a speech--was not onerous.
Having teethed on speeches, the head office realized that Unix could
also be useful for things that didn't need phototypesetting. Other
documents began to accumulate in their directory. By the time we became
aware of it, the hoard came to include minutes of AT&T board meetings.
It didn't seem like a very good idea for us to be keeping records from
the inner sanctum of the corporation on a computer where most everybody
had super-user privileges. A call to the PR guy convinced him of the
wisdom of keeping such things on their own premises. And so the CEO's
office bought a Unix system.
Just as one hears of cars chosen for their cupholders, so were these
users converted to Unix for trivial reasons: line numbers and vanity.
Doug