November 2019 - COFF - www.tuhs.org

by Lars Brinkhoff

I suggest continuing this on COFF. Thomas Paulsen wrote: > I have a account on a remote twenex PDP10. There is a editor named > emacs. This is a very archaic piece of software. It doesn't know any > teco commands no matter how I tried. I'm pretty sure that this is > teco-emacs. Yes, it should be TECO Emacs. Normal use of Emacs rarely needs TECO commands. To get a TECO minibuffer type Meta-Altmode (Esc Esc). You should get a small window at the top of the terminal in which you can enter TECO commands. Execute them with double altmode as you would in any TECO. > I draw my own conclusions from these observations which are far away > from all these myths. I try to stay with the facts. I actually use TECO Emacs almost daily, and I have built it from sources. Some other information is based on email conversations among those who wrote Emacs.

4 years, 5 months

2
1
0 0

Re: [COFF] [TUHS] buffer overflow (Re: Happy birthday Morris worm

by Peter Jeremy

On 2019-Nov-12 17:49:46 -0500, Arthur Krewat <krewat(a)kilonet.net> wrote: >On 11/12/2019 5:41 PM, Robert Clausecker wrote: >> Oh please no. One of the things we've hopefully all learned from Pascal >> is that length-prefixed strings suck because you can't perform anything >> useful without copying the entire string. Keep in mind that C doesn't have a "string" type. The use of a NUL terminated char array is purely convention. There's nothing to stop someone using a length-prefixed array (though there's virtually no standard library support for that). >> Rob Pike and friends showed >> how to get strings and vectors right in the Go language where you have a >> builtin slice type which is essentially a structure >> >> struct slice(type) { >> type *data; >> size_t len, cap; >> }; That approach would have incurred a 12-byte overhead for each string or vector on a PDP-11 - that would have been a substantial disincentive on a memory-constrained system. >And none of that stops some programmer from doing slice.cap=255 - or is >it read-only? ;) Slices and strings are built-in types in Go. They can be modelled as the above structure but that is an implementation detail. It is possible to reduce the capacity of a slice (but not a string) but attempting to increase it will result in a runtime exception ("panic" in Go speak). -- Peter Jeremy

4 years, 5 months

1
0
0 0

Happy birthday, Per Brinch Hansen!

by Dave Horsfall

Computer scientist Per Brinch Hansen was born on this day in 1938; he was known for his work on "monitors" (now known as operating systems), concurrent programming, parallel processing, etc. -- Dave

4 years, 5 months

1
0
0 0

Re: [COFF] [TUHS] buffer overflow (Re: Happy birthday Morris worm

by Dave Horsfall

(Narrowly diverted in time to COFF from TUHS when I saw Warren's email, so I hope Warner is on it.) On Tue, 12 Nov 2019, Warner Losh wrote: > POSIX can't even recognize that leap seconds exist :( There's a movement afoot to abolish leap seconds because they are "inconvenient" or something; that will upset the astronomers and other people who care about the exact time. > All is not lost, though; use strncpy() instead of strcpy() etc. > > strncpy has two issues. First, it doesn't guarantee NUL termination. > Second, it always writes N bytes. It's for a fixed width data field, not > a variable length string whose buffer size is known. strlcpy is much > better, but still has some issues... Yeah, I knew about the NUL termination (or lack of it) - I didn't think to mention it. When I use it, I copy n-1 bytes and plant the NUL in there myself (depending on how I'm using it). And I wasn't aware of strlcpy() - thanks. Too many functions to keep track of these days.... Trivia: curious to see how Australia's "talking clock" (long gone in favour of NTP, alas) handled the leap second, I recorded it (it puts a gap before the last beep). It can be heard (and seen!) over on www.horsfall.org/leapsecond.webm . And yes, that old long-haired hippie is me... -- Dave

4 years, 5 months

1
1
0 0

In memoriam: Gene Amdahl

by Dave Horsfall

We lost computer architect Gene Amdahl on this day in 2015; responsible for "Amdahl's Law" (referring to parallel computing), he had a hand in the IBM-704, the System/360, and founded Amdahl Corporation (a clone of the 360/370 series). -- Dave

4 years, 5 months

2
2
0 0

In memorium: Douglas Rain

by Dave Horsfall

We lost him on this day in 2018; he was the voice of the rogue computer HAL on "2001" (hence the tenuous computer connection). -- Dave, who can't do that

4 years, 5 months

1
0
0 0

Happy Birthday, Donald Michie and Robert Fano!

by Dave Horsfall

Donald Michie, a computer scientist, was born in 1923; he was famous for his work in AI, and also worked at Bletchley Park on the "Tunny" cipher. And Robert Fano, computer scientist and Professor of Electrical Engineering at MIT, was born on this day in 1917. He worked with Claude Shannon on Information Theory, was involved in the development of time-sharing computers, and was Founding Director of Project Mac, which became MIT's AI Lab. -- Dave

4 years, 5 months

1
0
0 0

Manipulating time_t values (was: Unix half-billion years old 1985)

by Greg 'groggy' Lehey

[Moved to COFF] On Monday, 4 November 2019 at 16:59:22 -0500, John P. Linderman wrote: > I wrote a near-trivial "timestamp" command to make it easier to do time > arithmetic > > TZ=udt timestamp > 119 11 04 21 50 06 18204 1572904206 Mon Nov 4 21:50:06 2019 > TZ=udt timestamp 0 > 70 01 01 00 00 00 0 0 Thu Jan 1 00:00:00 1970 > ... FreeBSD has this functionality in date(1): TZ=UTC date -r 500000000 Tue 5 Nov 1985 00:53:20 UTC TZ=UTC date -r 1500000000 Fri 14 Jul 2017 02:40:00 UTC Greg -- Sent from my desktop computer. Finger grog(a)lemis.com for PGP public key. See complete headers for address and phone numbers. This message is digitally signed. If your Microsoft mail program reports problems, please read http://lemis.com/broken-MUA

4 years, 5 months

4
3
0 0

Re: [COFF] [TUHS] Happy birthday Morris worm

by Michael Kjörling

On 4 Nov 2019 15:27 -0500, from crossd(a)gmail.com (Dan Cross): > On Mon, Nov 4, 2019 at 1:58 PM Bakul Shah <bakul(a)bitblocks.com> wrote: >> I am surprised no one mentioned *The Shockwave Rider *by John Brunner, >> published in 1975. Excerpt: > > In the 1983 movie "Wargames", at the very end as the staff at NORAD > desperately try and disable the rogue artificial intelligence hell-bent on > starting World War III, at one point they make a suggestion to send a > "tapeworm" into the system", but it's judged too risky. In the 1984 movie _2010_, it seems using a tapeworm was more of a standard, if unusual, procedure for solving a very different problem. Copying from <https://en.wikiquote.org/wiki/2010:_The_Year_We_Make_Contact#Dialogue> > Dr. Chandra: I've erased all of HAL's memory from the moment the > trouble started. > > Dr. Vasili Orlov: The 9000 series uses holographic memories, so > chronological erasures would not work. > > Dr. Chandra: I made a tapeworm. > > Dr. Walter Curnow: You made a what? > > Dr. Chandra: It's a program that's fed into a system that will hunt > down and destroy any desired memories. > > Dr. Floyd: Wait... do you know why HAL did what he did? > > Dr. Chandra: Yes. It wasn't his fault. I also suggest to migrate this part of the discussion to COFF as it has very little to do with UNIX history per se. -- Michael Kjörling • https://michael.kjorling.se • michael(a)kjorling.se “The most dangerous thought that you can have as a creative person is to think you know what you’re doing.” (Bret Victor)

4 years, 5 months

1
0
0 0

Re: [COFF] [TUHS] Happy birthday, Morris Worm!

by Rudi Blom

>From: Clem Cole <clemc(a)ccc.com> >To: Dan Cross <crossd(a)gmail.com> >Cc: Computer Old Farts Followers <coff(a)tuhs.org>, Dave Horsfall <dave(a)horsfall.org>, >The Eunuchs Hysterical Society <tuhs(a)tuhs.org> >Bcc: >Date: Fri, 1 Nov 2019 14:55:19 -0700 >Subject: Re: [COFF] [TUHS] Happy birthday, Morris Worm! >+1. Well said Dan. > >We all have made and will make mistakes in the future. It was an error and we all learned >from it. It’s not helpful to continue to hark back on it. Of course after having had my monthly Windows update session I really wonder if we learned from it. Cheers, uncle rubl

4 years, 6 months

2
2
0 0

2024

2023

2022

2021

2020

2019

2018

COFF November 2019