This is a multi-part message in MIME format. ------=_NextPart_000_0018_01C1C670.88043B20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Good post David! I liked reading it..... Never knew Multics came out of the I-17/TBird facility. ----- Original Message -----=20 From: David P. Schwartz=20 To: plug-discuss@lists.plug.phoenix.az.us=20 Sent: Friday, March 08, 2002 5:03 AM Subject: Re: History question Multics was a humongous (for that time) project funded in large part = by the government (DARPA, I believe) and developed by GE/Honeywell = largely here in Phoenix (at the Thunderbird and I-17 facility). It was = the first time that anybody had attempted to implement security = mechanisms directly within the hardware itself. It started around = 1967-68, and kept many thousands of techies well employed here for over = a decade. (I used to work with a bunch of guys who worked on Multics = forever.)=20 They said that there was an ongoing debate about whether all the = expense of implementing the security stuff in hardware was really = necessary. It was a huge undertaking. Reportedly, some guys at Bell = Labs got together and decided to see if they could implement a = software-only design that was as secure as the Multics model. Hence, = "Unix" became a loose acronym for "Unix is not Multics".=20 Part of the problem with having security stuff in hardware was that = nothing was symmetric -- you had to go through the hardware "gates" to = get access to various system functions that only worked in one = direction. So one of the guiding principles of the overall Unix design = was to make things as symmetric as possible. Hence, the evolution of = pipes on the command line and the ability to send a file in one end of a = pipe and have it come out the other end, and feed the output back into = the same things only reversed and get the original data back.=20 Multics had something like 8 security "rings" that were supported by = hardware, modeled roughly after the typical kind of security methods = used to protect physical stuff. Unix implemented three levels of = security based on roles: "user", "group" and "world". It took a while = before the military decided that role-based security was a more = effective approach.=20 Multics was designed for a machine with something like 128k words of = memory. Unix was designed on and for a PDP-8 (with 8k words of memory) = and later a PDP-11 with 32k words of memory. This was due in large part = to the fact that their newly designed programming language, called 'c', = evolved on that hardware, and that's what they had available to them.=20 (I remember when ASU's Engineering Computing Center got a bank of = brand new PDP-11Ms and they installed Unix on a couple of them. The = others were running RSTS-E, a fairly traditional "time sharing" terminal = server. The Unix machines kicked-butt over the other machines! I think = that was back in late 1978 or early 79. I graduated in May of 79, and = heard that within a couple of years, they were all running Unix. RSTS = was out.)=20 Another "feature" of Multics was that it was the target of another = HUGE undertaking of the Govt, in that it's primary language was a = variant of PL/1 called PL/Multics, if I recall correctly. Again, the = choice by Unix developers to use a language that was regarded at the = time as barely a step above assembly code was notable.=20 Everything about Unix was pretty much deliberately chosen to be "not = Multics".=20 AT&T used to freely license Unix to educational institutions. = Berkeley became a hot-bed of independent research and development = efforts, and they spawned a significant amount of re-design of both the = kernel and many of the command-line utilities. Berkeley had some kind = of an arrangement with AT&T to sell versions of their software to = commercial organizations; that was where the old BSD code originated. = When AT&T spun off Bell Labs, the bean counters started going nuts. I = was working at Motorola at that time with the team that was porting Sys = V to the 68020. They started getting legal beagles in the loop on = things that they never gave a second thought to before that.=20 Some sort of controversy arose between the Regents of the UC Schools, = the profs doing the work at UCB, and Bell Labs over licensing. It was = resolved by everybody agreeing that the "Unix" trademark was the = exclusive property of Bell Labs, that nothing from UCB could use that = name unless it was qualified as being the "Berkeley version", hence the = use of "BSD" on everything. And the sales revenues would all go to the = UC School System, rather than the developers at UCB. Bell Labs put a = relatively high price on their software licenses, so most people favored = the BSD version. Big corporations licensed from the Labs, but everybody = else went with BSD because it was practically free (the professors = didn't see any point in charging if the monies were only going into = state coffers).=20 Moto was porting Sys V to the 68020 under contract by the Labs, so = they didn't run into the same problem as UCB did. But then, nobody ever = really trusted Motorola's Unix software for some reason, preferring to = buy it from Bell Labs directly.=20 (tangent: In the early 70s, Gary Kildall was teaching at the Naval = PostGraduate School in Monterey where he invented a small programming = language that he called PL/M -- a "Programming Language for Micros". He = used it to write CP/M [a Control Program for Microprocessors, also = modelled loosely after Unix] that was a popular OS for 8080-based = computers. He tried selling both to Intel around 1976, but Intel wasn't = buying. Bill Gates tried to buy it around 1978, but Gary was busy = golfing. PL/M was eventually "appropriated" by Intel, and they used it = to create a knock-off of CP/M they called ISIS. PL/M went on to become = Intel's primary development language until 'c' compilers became so = pervasive in the late 80's that they couldn't rape and pillage ... uhh, = I mean ... sell their PL/M tools any more. Bill Gates left Gary to his = golfing and then went out and bought this thing called "DOS" from = Seattle Computer Works. Anybody remember the word that used to be in = front of "Digital Research" before Gary shortened it?)=20 Here's some trivia y'all probably don't know... Some Multics hardware = architects got hired by Intel around 1977, and the 286 was given a = 4-ring security model adopted from Multics. A couple of Multics = software architects were hired as well to develop what was supposed to = be RMX-86, a fully secure real-time multi-tasking executive that took = advantage of the new security features. Unfortunately, the chip = designers went off in the weeds and implemented some "features" that = prevented any real software support, so nobody ever released a decent OS = that worked in "protected mode" on that chip. (I worked on the RMX-86 = team at Intel where we were trying to do it, and we determined it = couldn't be done!) So the world had to wait until the 386 showed up a = few years later for their first taste of "real" security in a = microprocessor. It took Microsoft to release Windows NT and IBM's OS/2 = before anybody took much advantage of the security features built into = all of Intel's x86 family of chips since the 386.=20 I'd be curious to know when the first protected-mode version of Unix = was ever implemented on an x86-based machine. I can't recall if Minix = ran in protected-mode or not. People avoided the Intel architecture = like the plague until the mid-80's, ostensibly because they believed the = architecture was somehow "warped".=20 What most people don't realize is that when Intel designed their 286, = they deliberately chose an architecture modelled after the largest and = most successful computer company in the world at that time -- IBM. The = 286 was designed to be roughly 1/2 of an IBM 360 CPU. IBM was funding = LOTS of R&D to find out how to improve compiler technology, and Intel = figured it would make it easier to hire "experts" if their architecture = closely reflected what these guys were already studying! For a while in = the early 80's, Intel had one of the sharpest compiler teams in the = industry.=20 Unix was originally developed on PDP machines. These computers had a = "flat" architecture where all peripherals were memory-mapped -- they = appeared like storage registers in the regular memory space -- unlike = the "segmented" architecture used by IBM that had a separate set of I/O = ports for peripheral interfaces. Motorola adopted the PDP model. Their = 6800 and the Intel 8080 weren't all that different if you ignored how = they dealt with peripheral devices. But the 68000 and the 286 suddenly = looked like they came from different planets. It was probably that = architectural resistance that kept people from seriously porting Unix to = the x86 world.=20 Today the world has inverted -- the newest stuff is almost always = released first on Intel platforms, and then later on others. (Anybody = know where can I get a copy of Red Hat 7.1 for SPARC-IIi's?)=20 -David Schwartz=20 From: "Michael F. March"=20 To:=20 Subject: Re: History question Date: Thu, 7 Mar 2002 21:56:51 -0700 Reply-To: plug-discuss@lists.plug.phoenix.az.us UNIX was developed on a lark. The two inventors where on the Multics team and when AT&T pulled out of the project they recreated a lite version internally in AT&T. > I've read that AT&T developed Unix under US Government grant (DARPA > Project) which is why they couldn't sell it. > > George ------=_NextPart_000_0018_01C1C670.88043B20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
------=_NextPart_000_0018_01C1C670.88043B20------- Original Message -----From:=20 David P.=20 SchwartzSent: Friday, March 08, 2002 = 5:03=20 AMSubject: Re: History = questionMultics was a humongous (for that time) project funded = in large=20 part by the government (DARPA, I believe) and developed by = GE/Honeywell=20 largely here in Phoenix (at the Thunderbird and I-17 facility). = It was=20 the first time that anybody had attempted to implement security = mechanisms=20 directly within the hardware itself. It started around 1967-68, = and kept=20 many thousands of techies well employed here for over a decade. = (I used=20 to work with a bunch of guys who worked on Multics forever.)=20They said that there was an ongoing debate about whether all the = expense of=20 implementing the security stuff in hardware was really = necessary. It was=20 a huge undertaking. Reportedly, some guys at Bell Labs got = together and=20 decided to see if they could implement a software-only design that was = as=20 secure as the Multics model. Hence, "Unix" became a loose = acronym for=20 "Unix is not Multics".=20
Part of the problem with having security stuff in hardware was that = nothing=20 was symmetric -- you had to go through the hardware "gates" to get = access to=20 various system functions that only worked in one direction. So = one of=20 the guiding principles of the overall Unix design was to make things = as=20 symmetric as possible. Hence, the evolution of pipes on the = command line=20 and the ability to send a file in one end of a pipe and have it come = out the=20 other end, and feed the output back into the same things only reversed = and get=20 the original data back.=20
Multics had something like 8 security "rings" that were supported = by=20 hardware, modeled roughly after the typical kind of security methods = used to=20 protect physical stuff. Unix implemented three levels of = security based=20 on roles: "user", "group" and "world". It took a while before = the=20 military decided that role-based security was a more effective = approach.=20
Multics was designed for a machine with something like 128k words = of=20 memory. Unix was designed on and for a PDP-8 (with 8k words of = memory)=20 and later a PDP-11 with 32k words of memory. This was due in = large part=20 to the fact that their newly designed programming language, called = 'c',=20 evolved on that hardware, and that's what they had available to them.=20
(I remember when ASU's Engineering Computing Center got a bank of = brand new=20 PDP-11Ms and they installed Unix on a couple of them. The others = were=20 running RSTS-E, a fairly traditional "time sharing" terminal = server. The=20 Unix machines kicked-butt over the other machines! I think that = was back=20 in late 1978 or early 79. I graduated in May of 79, and heard = that=20 within a couple of years, they were all running Unix. RSTS was = out.)=20
Another "feature" of Multics was that it was the target of another = HUGE=20 undertaking of the Govt, in that it's primary language was a variant = of PL/1=20 called PL/Multics, if I recall correctly. Again, the choice by = Unix=20 developers to use a language that was regarded at the time as barely a = step=20 above assembly code was notable.=20
Everything about Unix was pretty much deliberately chosen to be = "not=20 Multics".=20
AT&T used to freely license Unix to educational = institutions. =20 Berkeley became a hot-bed of independent research and development = efforts, and=20 they spawned a significant amount of re-design of both the kernel and = many of=20 the command-line utilities. Berkeley had some kind of an = arrangement=20 with AT&T to sell versions of their software to commercial = organizations;=20 that was where the old BSD code originated. When AT&T spun = off Bell=20 Labs, the bean counters started going nuts. I was working at = Motorola at=20 that time with the team that was porting Sys V to the 68020. = They=20 started getting legal beagles in the loop on things that they never = gave a=20 second thought to before that.
Some sort of controversy arose = between=20 the Regents of the UC Schools, the profs doing the work at UCB, and = Bell Labs=20 over licensing. It was resolved by everybody agreeing that the = "Unix"=20 trademark was the exclusive property of Bell Labs, that nothing from = UCB could=20 use that name unless it was qualified as being the "Berkeley version", = hence=20 the use of "BSD" on everything. And the sales revenues would all = go to=20 the UC School System, rather than the developers at UCB. Bell = Labs put a=20 relatively high price on their software licenses, so most people = favored the=20 BSD version. Big corporations licensed from the Labs, but everybody = else went=20 with BSD because it was practically free (the professors didn't see = any point=20 in charging if the monies were only going into state coffers).=20Moto was porting Sys V to the 68020 under contract by the Labs, so = they=20 didn't run into the same problem as UCB did. But then, nobody = ever=20 really trusted Motorola's Unix software for some reason, preferring to = buy it=20 from Bell Labs directly.=20
(tangent: In the early 70s, Gary Kildall was teaching at the Naval=20 PostGraduate School in Monterey where he invented a small programming = language=20 that he called PL/M -- a "Programming Language for Micros". He = used it=20 to write CP/M [a Control Program for Microprocessors, also modelled = loosely=20 after Unix] that was a popular OS for 8080-based computers. He = tried=20 selling both to Intel around 1976, but Intel wasn't buying. Bill = Gates=20 tried to buy it around 1978, but Gary was busy golfing. PL/M was = eventually "appropriated" by Intel, and they used it to create a = knock-off of=20 CP/M they called ISIS. PL/M went on to become Intel's primary=20 development language until 'c' compilers became so pervasive in the = late 80's=20 that they couldn't rape and pillage ... uhh, I mean ... sell their = PL/M tools=20 any more. Bill Gates left Gary to his golfing and then went out = and=20 bought this thing called "DOS" from Seattle Computer Works. = Anybody=20 remember the word that used to be in front of "Digital Research" = before Gary=20 shortened it?)
Here's some trivia y'all probably don't know... = Some=20 Multics hardware architects got hired by Intel around 1977, and the = 286 was=20 given a 4-ring security model adopted from Multics. A couple of = Multics=20 software architects were hired as well to develop what was supposed to = be=20 RMX-86, a fully secure real-time multi-tasking executive that took = advantage=20 of the new security features. Unfortunately, the chip designers = went off=20 in the weeds and implemented some "features" that prevented any real = software=20 support, so nobody ever released a decent OS that worked in "protected = mode"=20 on that chip. (I worked on the RMX-86 team at Intel where we = were trying=20 to do it, and we determined it couldn't be done!) So the world = had to=20 wait until the 386 showed up a few years later for their first taste = of "real"=20 security in a microprocessor. It took Microsoft to release = Windows NT=20 and IBM's OS/2 before anybody took much advantage of the security = features=20 built into all of Intel's x86 family of chips since the 386.=20I'd be curious to know when the first protected-mode version of = Unix was=20 ever implemented on an x86-based machine. I can't recall if = Minix ran in=20 protected-mode or not. People avoided the Intel architecture = like the=20 plague until the mid-80's, ostensibly because they believed the = architecture=20 was somehow "warped".=20
What most people don't realize is that when Intel designed their = 286, they=20 deliberately chose an architecture modelled after the largest and most = successful computer company in the world at that time -- IBM. = The 286=20 was designed to be roughly 1/2 of an IBM 360 CPU. IBM was = funding LOTS=20 of R&D to find out how to improve compiler technology, and Intel = figured=20 it would make it easier to hire "experts" if their architecture = closely=20 reflected what these guys were already studying! For a while in = the=20 early 80's, Intel had one of the sharpest compiler teams in the = industry.=20
Unix was originally developed on PDP machines. These = computers had a=20 "flat" architecture where all peripherals were memory-mapped -- they = appeared=20 like storage registers in the regular memory space -- unlike the = "segmented"=20 architecture used by IBM that had a separate set of I/O ports for = peripheral=20 interfaces. Motorola adopted the PDP model. Their 6800 and = the=20 Intel 8080 weren't all that different if you ignored how they dealt = with=20 peripheral devices. But the 68000 and the 286 suddenly looked = like they=20 came from different planets. It was probably that architectural=20 resistance that kept people from seriously porting Unix to the x86 = world.=20
Today the world has inverted -- the newest stuff is almost = always=20 released first on Intel platforms, and then later on others. = (Anybody=20 know where can I get a copy of Red Hat 7.1 for SPARC-IIi's?)=20-David Schwartz=20
From: "Michael F. = March"To: Subject: Re: History question Date: Thu, 7 Mar 2002 21:56:51 -0700 Reply-To: plug-discuss@lists.plug.phoenix.az.us UNIX was developed on a lark. The two inventors where on the Multics team and when AT&T pulled out of the project they recreated a lite version internally in AT&T. > I've read that AT&T developed Unix under US Government grant = (DARPA > Project) which is why they couldn't sell it. > > George