A long time ago at the University that I graduated from. . .
Shell scripts had just added the ability to have functions in them, so I wrote a script to do some processing of files that I had, and then logged off to let it run in the background.
The shell script was named 'A'.
In the script was a function, named 'A'
When the script ran, instead of calling 'A' the function, it called 'A' the script, and you can see where this goes from here.
2 days later I received an email from the admin (thankfully a friend) who enclosed the 'ps -axl' output from the machine. It showed thousands of copies of my script running and a load that indicated that the machine was useless for almost everything.
With the admonishment: "Don't ever do this again."
I haven't.
David
David Barto
barto(a)kdbarto.org
barto(a)ucsd.edu
On Mon, Dec 26, 2011 at 8:15 PM, Dave Horsfall <dave(a)horsfall.org> wrote:
> On Tue, 27 Dec 2011, Warren Toomey wrote:
>> Yes, a good reminder on the power that programming brings us. A question
>> though: what command would "bring the system down"?
>
> It's right here: "Programmers were free to poke around to see and directly
> manipulate what was in the computer's memory."
http://minnie.tuhs.org/pipermail/unix-jun72/2008-May/000250.html
> -- Dave
--
Tim Newsham | www.thenewsh.com/~newsham | thenewsh.blogspot.com
Hi,
I wonder if someone has an early version of top lying around? I'd
like to try getting it to work on my ZEUS clone. I'd start with
1.0 from 1984 if possible ;)
Regards, Oliver
Hi,
I'm trying to re-create the source files for the Z8000 UNIX I have
on my Z8000 system (it is a S8000+ZEUS clone).
Easy programs like sync.c where easy. But when argc/argv is involved,
I'm not able to generate 1:1 matching binary code.
I'm working on /etc/unlink for now.
I tried the following C file:
char whatstr[] = "@[$]unlink.c 2.1 07/23/82 21:19:30 - 87wega3.2";
main(argc, argv)
int argc;
char **argv;
{
if(argc!=2) {
write(2, "Usage: /etc/unlink name\n", 24);
exit(1);
}
unlink(argv[1]);
exit(0);
}
The original ASM code for the beginning of main() until the argc
check is:
0042 abf3 dec r15,#4
0044 5df60000 ldl %0000(r15),rr6
0048 0b070002 cp r7,#%0002
The ASM code my C file generates is:
0042 abf3 dec r15,#4
0044 1df6 ldl @r15,rr6
0046 0b070002 cp r7,#%0002
keep in mine, that r15 is considered as the "stack pointer".
I wonder how to get the ldl from the original binary.
I also tried to declare argv with "char *argv[]" which
resulted in the same code. Forcing the compiler to store
argv into a register by using the "register" keyword results
in completly different code:
(sp = stack pointer = r15)
#17 adb unlink
ADB: P8000 1.6
? 0x0042/i
%0042: dec sp,#6
?
%0044: ld %0004(sp),r14
?
%0048: ld %0002(sp),r7
?
%004c: ld r14,r6
?
%004e: cp r7,#%0002
? $q
#18
Maybe the C compiler used to compile /etc/unlink differs from
the C compiler shipped with the system (maybe an older version)
but I don't want this to be true for now ;)
Anyone with deeper ASM and C knowledge than me sees what could
be done here?
Before someone asks - yes I'm sure the source file was in C
and not ASM based on the whatstr. Symboltable of the original
/etc/unlink is empty as well (striped binary).
Regards, Oliver
Sven Mascheck:
With "original implementation (post 7th ed", I meant the undistributed
BellLabs-internal further development of 7th, the first system ever
to implement #!, leading to 8th ed, etc. (4BSD just incorporated this).
Not System V or other relatives, though.
=======
Can you cite a reference?
I'm quite familiar with what went on inside the system that was
later called 8th Edition, having been on the inside at Bell Labs
starting in mid-1984. But that was after the original research
group's general move to VAXes--they had no PDP-11s left by then,
except a few LSI-11s running special-purpose systems rather than
UNIX. In fact the VAX kernel they had adopted, I think sometime
earlier that year, was derived from that of 4.1 BSD. (It diverged
quite a bit from that start later, for which I am appreciably
to blame, but that has nothing to do with #!).
So if #! was implemented in an earlier kernel I don't know just
what was done. I'd assumed it was no different; if I'm
mistaken I'd love to see just how it really was.
Alas, the person I know was on the spot and was likely to
remember just what happened in what order can no longer answer
questions ...
Norman Wilson
Toronto ON
Sven Mascheck:
Well the original implementation (post 7th ed and 4.0/4.1 BSD)
didn't allow arguments at all ;-)
======
I believe you're mistaken. All the implementations I've
ever used allowed a single argument in the #! line,
and inserted the name of the script between that (if
present) and the arguments given to exec.
e.g. if ./lipsum began with
#!/usr/bin/awk -f
awk would be invoked with `/usr/bin/awk -f ./lipsum ...'.
Without allowing one argument for -f or the like,
#! wouldn't have been useful for much but the shell.
Norman Wilson
Toronto ON
Hi all, in the past few days I've been getting some
interesting e-mails from a new TUHS member,
Jonathan Gevaryahu. He has been searching for some
lost software, and his story of how he found it
is a good reminder to check through all the zeroes
and ones on the digital media at hand. With his
permission, I reproduce the e-mails below.
Cheers,
Warren
Hi, I'm Jonathan Gevaryahu, one of the developers of MESS but also a
speech synthesis history buff. I've been trying to find a copy of the
old unix 'speak' command source code and rule tables that M. D. Mcilroy
wrote back in 1974ish, but the TUHS archives only have the man pages
for it, and not the actual program or its tables.
As for the "why?" of this, its an important piece of history, and the
phoneme set used on the Federal Screw Works "VOTRAX" Model VS-4 unit
which was used with 'speak' at Bell Labs is compatible with the later
Votrax Model VS-6 unit at CHM, and also with the Votrax "SC-01" chip
used in some arcade/video games, several computer peripherals, and on
the "Type 'N' Talk" and "Personal Speech System" products. So actually
running the old code and having it speak should be quite doable, if we
can recover enough of it to be useful.
[ Jonathan assumed that the 'speak' source code had been lost. ]
I even asked Doug McIlroy about it a few years ago and he didn't have
a copy, and I had assumed it was just plain lost... Until today.
I was poking around in random TUHS files (after reading about
the v1 unix restoration project) and noticed that the size of
recovered files from the ritchie v6 tapes in the .tar.gz files
is actually significantly smaller than the tapes themselves. I
assumed there had to be some other data there, possibly corrupt or
fragmentary, and got down to peeking at the file contents themselves.
There were some mentions of speak.m and .c and .v, but finally, in
http://minnie.tuhs.org/Archive/PDP-11/Distributions/research/Dennis_v6/v6do…
I found the remains of the speak program. See
http://pastebin.com/FdvRYM2T for what I've managed to recover so far
(actually since i pasted that I recovered a good deal more of it, but
a lot is out of order and bits are missing) The file is fragmentary as
far as I can see, and is only speak.c (the .m file containing the rules
I haven't found yet, but since Doug has a scanned copy of the paper
describing speak on his website, hopefully I can just regenerate the
rule tables if needed), but it is there! Hopefully speak.m or .v are
still waiting to be found on that or one of the other tape images.
Also there are other things on that tape like the chess program, and
tic tac toe, which may not exist elsewhere. (Though, for these two I
honestly haven't checked)
Also, in the last 5 minutes I found a chunk of what I'm pretty sure is
either speak.m or speak.v, so there's more than just the .c file there.
Further progress attached of recovering speak from deleted disk pack
sectors: I have all of speak.c in order except for one 512-byte sector,
which was overwritten at some point, in the phoneme table. (This has to
be the least "damaging" sector of the entire program. lucky!) I also
have a good chunk (maybe 50-60%) of what may be a mix of speak.m and
speak.v, both out of order. I did not yet find
a copy of 'speakm', the rule displayer program for speak.m/.v. There is
a program, located after speak.c on the disk image, which looks like it
would convert numbers and months to their full speakable names.
In addition, either slightly more or slightly less of the files may be intact
on the
http://minnie.tuhs.org/Archive/PDP-11/Distributions/research/Ken_Wellsch_v6…
image, which appears to be originally an exact dd-copy of the dennis_v6
disk packs.
Ok, here's the 'repaired' speak.c file, with the missing entries of the
table filled in (this was IMMENSELY helped by the fact that speak.o, the
compiled object file, was also on the disk pack and appears to be fully
intact including the table; the ruleset files are fragmentary so far.)
All, here's a special Christmas present, especially for those who
helped out with the restoration of the 1st Ed Unix system, see
http://code.google.com/p/unix-jun72/
To do the restoration we needed a copy of the 1st Ed Unix kernel
source code, and Al Kossow had found these two documents and
scanned them in:
http://minnie.tuhs.org/Archive/PDP-11/Distributions/research/Dennis_v1/Kern…http://minnie.tuhs.org/Archive/PDP-11/Distributions/research/Dennis_v1/Prel…
At the time nobody could work out who had studied the kernel source code,
why they had done it etc. Nor could we work out who Ted Bashkow was and
why he was involved.
After my IEEE Spectrum article I was contacted by Jim DeFelice to say
thanks for the article. I recognised him as one of the people named in
the above documents, and asked him about the kernel study. He has contacted
some of the people involved and sent me the e-mail below, which gives
a full description of the work!
Before I get to it, just an aside. According to Berkley Tague,
Ted Bashkow "was a visiting Professor for the summer some time around
1970 or 1971 and worked with me and others in research on various
topics. I don't believe he contributed much to UNIX at that time, but
was an early user of the early systems."
Cheers,
Warren
[ Jim's story]
Here is as coherent a story as I can piece together Let me know if you
have any more questions.
Jim.
The documents that describe the UNIX system as it was implemented on
the PDP-11/20
circa 1971 originated as a consequence of a project undertaken within
the comptrollers
department of the AT&T General Departments. The project was titled the
Investment and Cost Information System (ICIS). It was a major new
accounting system intended to track
detailed cost information for the operating telephone companies of the
Bell System.
ICIS was a major IBM mainframe based system which was being developed
in COBOL.
I transferred from Bell Labs in late 1970 to join Chuck Everhart who
preceded me from the Labs. In 1971 we were joined by Ron Silacci, Cathy
Judge, and later (early '72?) Jerry Conser all from Bell Labs. We
formed the core of what would become
a much larger Development staff by 1973.
In preparation for a major development effort, we wanted to develop a
system to maintain the spate of expected ICIS specification and design
documents including graphics such as flowcharts. We decided on the
PDP-11/20 with a Tecktronix T4002 graphics terminal as the hardware
platform for the development of our document maintenance system.
For obscure reasons, in order to purchase the PDP-11/20, the ICIS team
needed to get approval from the Bell Labs computer aquisition review
department headed
by Berkley Tague. Berk made the approval for the purchase contingent
us agreeing to use UNIX as the operating system.First hearing of this
"UNIX" verbally, my mind was filled with scenes from the Arabian
Nights. "Eunuchs" seemed a strange name for an operating system.
At the time, the only instances of UNIX were to be found in the hands
of the developers (Ken Thompson & Co.) at Murray Hill, NJ. We
naturally asked for all the documentation. We were told there was
none. What we got was a source listing of the PDP-11 assembly
language UNIX Kernel. It was virtually without any commentary or
external description. In order to proceed we undertook to reverse
engineer the listing in order to understand how to
modify UNIX to support the T4002. To that end, in late 1971, we set up
shop at a Labs facility in Piscataway, NJ. The team got occasional
hints and pointers from the UNIX developers at Murray Hill, but they
tended to be focussed on their own work (the C programmimg language,
troff, etc.). Initial progress was slow, but as the overall design
structure emerged and the team became fluent with PDP assembly
language and the coding style of the UNIX developers things moved
along. Early work was
done with paper and pencil resulting in the document named by you as
"Kernel Subroutine
Description...". Once we took delivery of our PDP-11/20, we were able
to make
use of the UNIX tools "ed" and "roff" to create a more easily edited
digital document
"Preliminary UNIX Implementation Document"
The detailed timing of all this is uncertain. The hand work was done
from late 1971 through
March 1972 resulting in the Kernel Subroutine documentation. Chuck
Everhart left AT&T
in late 1971 and I became the group supervisor. A draft of the machine
based Preliminary
Implementation document was completed by June 1972 per the date on my
cover letter for its first distribution. By June 1972 there was
evidently a lot of interest in UNIX inside Bell Labs. The computer
commitee was pushing UNIX for all PDP based projects inside Bell Labs.
The ICIS owned PDP-11/20 was probably received after March 1972. The
hand written cover letter to Ted Bashkow is dated 4/3/72. Once we had
use of the PDP-11 we would have entered our work directly. The
modifications for the T4002 are not dated in
your PDF version and do not appear in the original printout that I
still have. I don't know why the date on all the printed pages is
3/17/72. Also, missing in the PDF version of the Preliminary
Implementation document that is in the paper version is a subroutine
cross reference listing that lists which subroutines are called by
which.
Regarding the authorship of the documents. Looking at the handwriting
it seems
at least four people contributed to the Kernel Subroutine document.
Myself and Ron
have actually reviewed the document and can claim authorship to
specific sections. By sections:
J. DeFelice
H0_01, H0_02, H0_03,H0_04,H0_05, H2-11_sysexec call chain,
H2.4,H2_1.7,H2-8,
H2-9 H4-3, H5-1, H5-2, H5-3, H5-4, H5-7,
H7-1, H7-2, H7-4, H7-5,H7-6, H8-01.2, H8-02, H8-03, H8-05, H8-06,
H8-07,
H8-08, h8-09-00, h5-6
Ron Silacci
sysclose, syscreate, sysent, sysexit, sysfork, sysmdate, sysgetty,
sysmdir,
error, badsys, sysopen, sysret, sysrele, sysstty, syswait, read, write,
ani,
sysstat, sysgetuid, sysintr, syslink, sysseek, syssetuid, sysstat,
sysstime,
systime, sysquit, sysunlink, wdir, fclose, isdir, isown, maknod, mkdir,
getf,
seektell, sysbreak, syschdir, syschmod, syschown, clear, idle, putlu,
swap,
tswap, unpack, rswap, wswap, clock, isintr, retisp, sleepo, setisp,
tty0,
wakall, ttyi, wakeup, itrunc, imap, dskr, cpass, readi, canon, cesc,
ctty,
ttych, getspl, iclose, iopen, sysmount, sysumount, bread, bwrite,
dioreg, drum, preread, rtap, tape, tstdeve, trapt, rw1, intract, otty.
Unknown 1 (all caps)
H4_00, H4_01, H4_02, H4_2.1, H6_2.2, H6_3.0, H6_6, H7_0.0.4, H7_3.0,
H7_3.2
H7_3.3, H9_00.1, H9_01, H9_02, H9_03
Unknown 2
H0_06, H0_07, H2_0.2, H2_3,H2_4, H3_2, H3_4, H5_2.0, H5_2.1,H6_0.9,
H6_1.0,
H6_1, H6_2.0, H6_2.2, H6_3, H6_4, H8_09, H8_11
The two unknowns would be Jerry Conser and Cathy Judge. I have not
been able to track
them down.
The comments in the listing were made by the people who authored the
corresponding man pages. We would comment the listing and as
understanding dawned write up the man page. I had a major hand in
Section F but can't claim sole responsibility.
The people listed in the recipients list in Ted Bashkow's cover letter
are the members of the computer aquisition department. According to
Joe Maranzano:
"Ted Bashkow was a professor from Columbia who was on a 6-month
sabbatical in Berkley Tague's department.
The other names on the memo are:
Dan Clayton
David Copp
Gwen Hansen
Jossie Hintz
Ruth Klein
Jim Ludwig
Georgette Petit
Joe Ritacco
Berk Tague
Dan Vogel
Linda Wright
This was the composition of the Department in 1972 and most of us were
working on Computer Acquisition Reviews for
the Computer Centers. The Unix Support Group was formed in 1973."
By the time the Tecktronix application was developed, the ICIS
development project was ramping up. The developers were using punch
cards for their Cobol programs. It occurred to me that we could
utilize our UNIX system to eliminate punch cards which were difficult
to manage and instead enter and edit the Cobol code using "ed". My
management (rotated in from Bell Operating Companies) was not keen on
diverting resources towards
more tool building but I had enough autonomy to push through the
ordering of a PDP-11/45 and a DEC developed Bisync communications
interface card. This configuration allowed the UNIX system to emulate
an IBM card reader/printer.
The PDP11/45 had memory protection, which made committing all the
source code for a major project to UNIX thinkable. I did all the
development work on a bisync driver myself while my group attacked the
main IBM development. The resulting system worked well and over the
course of a few months all the die hard card rearder afficianados had
converted to the new system. This despite the occasional file system
crash. At the time you could go in and edit i-nodes by hand to recover
lost files and directories. So with frequent tape backups for insurance
we never lost more that a few hours worth of work.
The Bell Labs UNIX support department (formed in 1973) eventually took
over the maintenance of the system and dubbed it the Programmers Work
Bench. Other types of workbench were to follow. I lost track of
developments in the UNIX world till I transferred back to Bell Labs in
1982. By then the UNIX support organization was an entire
Laboratory. The hardware platform was the DEC VAX system, UNIX was
rewritten in C, and Berkely UNIX was a major competitor to the AT&T
version. I still have the design and code for the Bisync driver if you
are interested.
Arnold Skeeve:
Have you asked Doug McIlroy?
=======
Actually I did, last night, on Warren's behalf.
I had meant to drop Doug a note anyway to apologize
for not letting him know I was in his general neighborhood
last week.
Here's Doug's reply:
Pipes were first documented
in v3, Feb 1973. At that time my original clumsy shell
syntax, cmd>cmd>[file] was still in use. Within a few
months, Ken invented today's pipe symbol as something
more presentable at a talk he'd been invited to give
in England--an Infosys "State of the Art" conference
if I remember correctly (not the same Infosys as the
current Indian giant).
I also remember the very blackboard in the garret
lab where I sketched my syntax and Ken exclaimed,
"I'll do it". That was late in the day and I'm
quite sure it was dark outside. Unlike Ken, I
was not in the habit of staying in the lab into
the evening. That makes me think that pipe day
was not too far off the solstice.
It would be nice to believe that pipes preciptated
the third edition, but in fact the first four editions
came out almost like clockwork at 8-month intervals,
so any correlation with pipes is highly speculative.
======
Norman Wilson
Toronto ON
(actually Ramsey NJ at the moment, a good bit north of Murray Hill)
