TUHS

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6464 discussions

Re: [TUHS] Who's behind the UNIX filesystem permission

by Doug McIlroy

Read and write permission were common ideas--even part of the Atlas paging hardware that was described before 1960. The original concept of time-sharing was to give a virtual computer to each user. When it became clear that sharing was an equally important aspect, owner/other permissions arose. I believe that was the case with Multics. Owner/other permissions were in PDP-11 Unix from the start. Group permissions arose from the ferment of daily talk in the Unix lab. How might the usual protections be extended to collaborative projects? Ken and Dennis deserve credit for the final implementation. Yet clean as the idea of groups was, it has been used only sporadically (in my experience). Execute permission (much overloaded in Unix) also dates back to the dawn of paging. One Unix innovation, due to Dennis, was the suid bit--the only patented feature in the Research system. It was instantly adopted for maintaining the Moo (a game now sold under the name "Master Mind") league standings table. One trouble with full-blown ACLs as required by NSA's Orange Book, is obscurity. It is hard (possibly NP- complete) to analyze the actual security of an ACL configuration. A common failing of Unix administration was a proliferation of suid-root programs, e.g. mail(1). I recall one system that had a hundred such programs. Sudo provided a way station between suid and ACLs. Doug

5 years, 8 months

Re: [TUHS] Who's behind the UNIX filesystem permission

by jnc＠mercury.lcs.mit.edu

> From: Arthur Krewat > there's the setuid bit on directories - otherwise known as the sticky > bit. Minor nit; in V6 at least (not sure about later), the 'sticky' bit was a separate bit from SUID and SGID. (When set on a pure/split object file, it told the OS to retain the text image on the swap device even when no active process was using it. Hence the name...) Noel

5 years, 8 months

Video of PDP-7 with Graphics-2?

by Warren Toomey

Hi all, I'm chasing the Youtube video of the PDP-7 at Bell Labs where people are using it to draw circuit schematics. This seems to show the Graphics-2 module that, I believe, was built at the Labs. Can someone e-mail the URL? I've done some grepping but I haven't found it yet. Thanks, Warren

5 years, 8 months

Re: [TUHS] Additional groups and additional directory permissions

by Norman Wilson

Thomas Paulsen: isn't Kirk McKusic a member of our group? ==== Kirk is a member of many groups, all at the same time. Norman Wilson Toronto ON

5 years, 8 months

Who's behind the UNIX filesystem permission implementation

by Stephan Han.

Hello Unix enthusiasts. I'd like to know who or the group of people behind implementing this filesystem permission system. Since we are using this system for nearly 40 years and it addresses all the aspects of the permission matter without any hustle. I'm inspired to know who/how came up with this theory? Also if it derived from somewhere else or If there's an origin story about this, it would be worth to share. Cheers. Stephan -- No When

5 years, 8 months

DMERT

by Kevin Bowling

I was talking about DMERT today and Larry McVoy was wondering if it slipped out in any fashion. I believe there were official trainers as well as a production emulator that ran it on Solaris/SPARC. I have never seen them anywhere. Old phone phreaks I’m acquainted with had illicit access. Does anyone know if source or the trainer or emulator are tangible? I enjoyed the BTSJ on DMERT as much as the Unix articles. Highly recommend reading. Regards, Kevin

5 years, 8 months

just over 32 years ago

by Charles H Sauer

https://technologists.com/photos/1987/fullsize/1987ThompsonRitchie.jpg (thanks to Mike Tilson) -- voice: +1.512.784.7526 e-mail: sauer(a)technologists.com fax: +1.512.346.5240 Web: https://technologists.com/sauer/ Facebook/Google/Skype/Twitter: CharlesHSauer

5 years, 8 months

PCC for the i386

by Jason Stevens

Does anyone know where the 386 port from PCC came from? While trying to build a Tahoe userland for the i386, it seems that everything was built with GCC… Was there a PCC for the i386 around ’88-90? It seems after the rapid demise of the Tahoe/Harris HCX-9 that the non Vax/HCX-9 platforms had moved to GCC? Also anyone know any good test software for LIBC? I’ve been tracing through some strange issues rebuilding LIBC from Tahoe, where I had to include some bits from Reno to get diropen to actually work. I would imagine there ought to have been some platform exercise code to make sure things were actually working instead of say building as much as you can, and playing rogue for a few hours to make sure its stable enough.

5 years, 8 months

Re: [TUHS] BSD/386 (was: Old 386 Unix Versions, was: Re: PCC for the i386)

by Richard Tobin

> BSD[Ii] got in trouble with AT&T for their sales number, which was > 1-800-ITS-UNIX. I don't know if they ever got officially sued or not. There was a joke that MIT should have sued them too, for violating their trademark on ITS. -- Richard -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.

5 years, 8 months

Re: [TUHS] Old 386 Unix Versions, was: Re: PCC for the i386

by Rudi Blom

>Does anyone have documentation or history for European efforts in the Unix-like operating systems? For example there was Bull’s Chorus which I seem to recall was based on Mach or a competing microkernel (it was a very long time ago and I used it for no mare than about two hours..). >I am rather saddened by the fact that there is so much about all the Unix (and not only >Unix) history of computing in the USA and so very little in Europe. I wouldn’t even know >where to start, to be honest, all I have as a history is the Italian side from my father and his other mad friends and colleagues in Milan. So little of it is recorded, never mind written down. In the 80-tisch I worked at Philips Data Systems in Apeldoorn, the Netherlands. Not in Development, but in System Support. Philips was working on a System V.3 based UNIX running on Motorola 68000 CPUs in a P9X00 server. Called MPX as in Multi-Processor UNIX. The Multi part refers to having an Ethernet, X25 and SDLC board running a tailored version of the OS to offload the main CPU. See for example https://www.cbronline.com/news/better_late_philips_enters_the_uk_unix_marke… https://www.cbronline.com/news/philips_ready_with_68030_models_for_its_p900… Later Philips moved to i386 with a 'unknown version' based UNIX. Division was bought by DEC (some say sold off by Philips) in 1991 and we moved to DEC's choice of SCO UNIX. The 'intelligent comm boards were ported and still running the separate OS though. Unfortunately I never had any of that OS type of source and my paper archive was left behind. Only have some small higher level test stuff and my mail archive. For a while I was "rudi blom" <blom(a)kiwi.idca.tds.philips.nl>, later rudi blom"@apd.mts

5 years, 8 months

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