TUHS

tuhs@tuhs.org

34 participants
6418 discussions

by jnc＠mercury.lcs.mit.edu

> From: William Corcoran > I think it's a bit more interesting to uncover why rm does not remove > directories by default thereby obviating the need for rmdir On early PDP-11 Unixes, 'rm' is an ordinary program, and 'rmdir' is setuid-root, since it has to do special magic (writing into directory files, etc). Given that, it made sense to have 'rm' run with the least amount of privilege needed to do its job. Noel

6 years, 8 months

Re: [TUHS] /dev/drum

by jnc＠mercury.lcs.mit.edu

> From: Johnny Billquist > For 1972 I only found the 11/40 handbook. I have a spare copy of the '72 /45 handbook; send me your address, and I'll send it along. (Every PDP-11 fan should have a copy of every edition of every model's handbooks... :-) In the meantime, I'm too lazy to scan the whole thing, but here's the first page of Chapter 6 from the '72: http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/jpg/tmp/PDP11145ProcHbook72pg6-1.j… > went though the 1972 Maintenance Reference Manual for the 11/45. That > one also says "page". :-) There are a few remnant relics of the 'segment' phase, e.g. here: http://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/sys/conf/m45.s which has this comment: / turn on segmentation Also, if you look at the end, you'll see SSR0, SSR1 etc (as per the '72 handbook), instead of the later SR0, SR1, etc. Noel

6 years, 8 months

Re: [TUHS] 3330s, 3340s, Winchesters... (was: /dev/drum)

by jnc＠mercury.lcs.mit.edu

> From: Paul Winalski <paul.winalski(a)gmail.com> > Regarding the Winchester code name, I've argued about this with Clem > before. Clem claims that the code name refers to various advances in > disk technology first released in the 3330's disk packs. Wikipedia and > my own memory agree with you that Winchester referred to the 3340. And you believe anything in Wikipedia? If so, I have a bridge to sell you! :-) But, in this case, it's correct. According to "IBM's 360 and Early 370 Computers" (Pugh, Johnson and Palmer - a very good book, BTW), pg. 507, the first Winchester was the 3340. The confusion comes from the fact that it had two spindles, each of 30MB capacity, making it a so-called "30-30" system - that being the name of Winchester's rifle. Noel

6 years, 8 months

Re: [TUHS] /dev/drum

by jnc＠mercury.lcs.mit.edu

> From: Johnny Billquist >> Well, the 1972 edition of the -11/45 processor handbook ^^ > It would be nice if you actually could point out where this is the > case. I just went through that 1973 PDP-11/45 handbook ^^ Yes, the '73 one (red/purple cover) had switched. It's only the '72 one (red/white cover) that says 'segments'. Noel

6 years, 8 months

Happy birthday, computer mouse!

by Dave Horsfall

Blimey, but I nearly missed this one (I was sick in bed). On this day in 1981, some little company called Xerox PARC introduced something called a "mouse" (mostly because it has a tail), but I'm struggling to find more information about it; wasn't there a photo of a big boxy device? -- Dave Horsfall BSc DTM (VK2KFU) -- FuglySoft -- Gosford IT -- Unix/C/Perl (AbW) People who fail to / understand security / surely will suffer. (tks: RichardM)

6 years, 8 months

Re: [TUHS] /dev/drum

by Johnny Billquist

On 2018-04-26 04:00, jnc(a)mercury.lcs.mit.edu (Noel Chiappa) wrote: > > From: Johnny Billquist > > > if you hadn't had the ability for them to be less than 8K, you wouldn't > > even try that argument. > > Well, the 1972 edition of the -11/45 processor handbook called them segments..:-) I think we had this argument before as well. It would be nice if you actually could point out where this is the case. I just went through that 1973 PDP-11/45 handbook, and all it says are "page" everywhere I look. I also checked the 1972 PDP-11/40 handbook, and except for one mention of "segment" in the introduction part of the handbook, which is not even clear if it actually specifically refers to the MMU capabilities, that handbook also use the word "page" everywhere. I also checked the PDP-11/20 handbook, but that one does not even cover any MMU, so no mention of neither "page" nor "segment" can be found. > I figure some marketing droid found out that 'paging' was the new buzzword, and > changed the name...:-) :-) Somehow I doubt it, but looking forward to your references... :-) Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt(a)softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

6 years, 8 months

/dev/drum

by Tim Bradshaw

I am sure I remember a machine which had this (which would have been running a BSD 4.2 port). Is my memory right, and what was it for (something related to swap?)? It is stupidly hard to search for (or, alternatively, there are just no hits and the memory is false). --tim

6 years, 8 months

Re: [TUHS] rm command

by jnc＠mercury.lcs.mit.edu

> From: Dave Horsfall <dave(a)horsfall.org> > I am constantly bemused by the number of "setuid root" commands, when a > simple "setgid whatever" will achieve the same task. http://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/sys/ken/sys4.c /* * Unlink system call. */ unlink() { ... if((ip->i_mode&IFMT)==IFDIR && !suser()) goto out; For many things, yes. Not in this particular case. Noel

6 years, 8 months

Looking for 3B2 SVR3 driver source code

by Seth Morabito

Hello all, I recently wrote a 3B2/400 simulator on the SIMH platform. It emulates the core system board and peripherals quite well, but I am now turning my attention to the emulating the 3B2 IO expansion boards. The first board I've emulated is the PORTS 4-port serial card, which came together fairly easily because I have the full source code for the SVR3 driver. Other cards, though, are more challenging because I do not have source code for them. I would like to emulate the following two cards: * The CTC cartridge tape controller * The NI 10base5 Ethernet controller Of these two, I have partial source code for the CTC driver (ct.c, ct.h, ct_lla.h, ct_deps.h), but I am missing a core file (ct_lla.c) that would greatly help explain what's going on. And I have NO source code at all for the NI driver. There was a source code package for the NI driver called "nisrc", probably distributed on tape or floppy, but I have never seen it. If you or anyone you know happens to have these source packages and a way to get at them, could you please let me know? I would be grateful. -Seth -- Seth Morabito web(a)loomcom.com

6 years, 8 months

Re: [TUHS] rm command

by Doug McIlroy

> Google didn't seem to turn up much on TML Perhaps because there was no TML. I suspect you mean TMG, which I implemented from scratch, based on Bob McClure's original, on both PDP 8 and PDP 11 Unix. Bob Morris and I used it to make EPL, the "early PL/I" compiler for Multics. Off topic, but TMG on the GE 635, usedto buld Multics got there via quite an Odyssey. Bob McClure created it for the CDC 1604. He tranliterated it by hand from 1604 assembly language to IBM 7090 and sent the green coding sheets to me. Debugging it was an unusual exercise: I knew the logic was right; allI had to do was ferret out mistranslations. The most prevalant problem was confusion between CLA (signed load) and CAL (unsigned). When we decided to do EPL, Clem Pease mechanically reproduced a 7090 inside a Ge 635, by defining 7090 instructions as macros--sometimes quite hairy, but they worked. Doug

6 years, 8 months

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TUHS