TUHS September 2020

tuhs@tuhs.org

60 participants
63 discussions

Re: [TUHS] Memory management in Dennis Ritchie's C Compiler

by jnc＠mercury.lcs.mit.edu

> From: Jim Geist > When did mmap(2) come about? Pretty sure it's a Berserkleyism. I think it came in with the VM stuff that DARPA mandated for VAX Unix (for the research project they funded). Noel

3 years, 2 months

/bin vs /sbin

by Grant Taylor

One of the things that I've noticed in my explorations into the H.J. Lu bootable root disks is that some of them predate the /sbin split in Linux. One of them has exactly one file in /sbin and other commands spread across /bin, /usr/bin, and /etc. The single file in /sbin is sln. To me, this makes it fairly self evident that /sbin was originally for statically linked binaries. At least in Linux. Does anyone have any history of /sbin from other traditional Unixes? I'd be quite interested in learning more. I also noticed that (at least) one of the early versions of the H.J. Lu disks had root's home directory in /usr/root. I seem to recall that one version used an atypical of /users vs /usr. Which as I understand it, goes back to the original / vs /usr split in Unix, before /home became a thing. -- Grant. . . . unix || die

3 years, 2 months

Troff to ps

by Will Senn

All, So... I've moved on from v7 to 2.11bsd - shucks, vi and tar and co. just work there and everything else seems to be similar enough for what I'm interested in anyway. So yay, I won't be pestering y'all about vi anymore :). One the other hand, now I'm interested in printing the docs. 2.11bsd comes with docs in, of all places, /usr/doc. In there are makefiles for making the docs - ok, make nroff will make ascii docs, and troff will make troff? docs using Ossana's 'original' troff. So, after adding -t to it so it didn't complain about 'typesetter busy', I got no errors. I mounted a tape, tar'ed my .out file and untar'ed it on my macbook (did it for the nroff and troff output). Then I hit the first snag, groff -Tps -ms troff.out > whatever.ps resulted in cannot adjust line and cannot break line errors and groff -Tps -ms nroff.out > whatever.ps resulted in a bunch of double vision. I seem to recall doing this in v6 and it working ok (at least for nroff). My questions: 1. Is there a troff to postcript conversion utility present in a stock 2.11 system (or even patch level 4xx system)? 2. Is there a way to build postscript directly on the system? 3. Is there an alternative modern way to get to ps or pdf output from the nroff/troff that 2.11 has? I'm still digging into the nroff stuff as that may be just minor diffs between ancient nroff macros and "modern" macros or even just errors (.sp -2 rather than .sp or .sp -1, .in -2 instead of .in +2), etc. Although, the files display ok in 2.11bsd using nroff -ms nroff.out... Thanks, Will -- GPG Fingerprint: 68F4 B3BD 1730 555A 4462 7D45 3EAA 5B6D A982 BAAF

3 years, 2 months

Re: [TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems

by jnc＠mercury.lcs.mit.edu

> From: Paul Riley > Is LSX the only option on the 11/03, or could I run V6 or Mini-Unix with > more RAM? All PDP-11 Unix versions from V4 on require the MMU, so the -11/03 is out for them. We don't have the code for V2-V4, though. So V1 (mostly all assembler, no C :-), LSW and Mini-Unix are the only options for it. V6 can be run on an -11/23 (I've done it), but not straight out of the box; it requires a few minor tweaks first: http://gunkies.org/wiki/Running_UNIX_V6_on_an_-11/23 Noel

3 years, 3 months

Status of Space Travel

by Warner Losh

What's the current state of efforts to get space travel working again? Warner

3 years, 6 months

Re: [TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems

by jnc＠mercury.lcs.mit.edu

> I think before I try debugging it directly, I'll try one of the other > Mini-Unix repositories; the one I've been using (from Bob Eager's site) > may have some bit-rot. Well, foo, the one from TUHS has the same symptom: random re-starts. Looks like I'm going to have to actually debug this. I guess the first step is to work out how the re-start is happening; I suspect it's not a trap (I'll check, but I think Mini-Unix catches them all). My best guess is a jump to 0 (somehow); if so, that should be easy to catch. Then the next thing is to try and work out where/how/why that is happening. Following a suggestion of Warner Losh, I think there's a good idea on how to make progress, which is to mount the Mini-unix pack under V6 (running on a simulator); that's rock-solid - and the V6 tool-chain can be used to build Mini-Unix binaries. And here I thought it was going to be easy to convert Mini-unix to run on an -11/03. Well, it still might - if I can get Mini-Unix to run reliably! Noel

3 years, 6 months

Bell Labs January 1968 Organizational Directory

by Diomidis Spinellis

David C. Brock posted on Twitter links to the Bell Labs January 1968 Organizational Directory scans. The Research, Communications Sciences Division is available at https://drive.google.com/file/d/171jywFyIDyyWUMX4jYl3Czblqe5VGX2q/view In it the Computing Science Research Center appears on tab 13, page 15 (PDF page 6). Most of the names are very familiar to members of this list; some are even posting here. Diomidis - https://www.spinellis.gr

3 years, 6 months

Re: [TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems

by jnc＠mercury.lcs.mit.edu

> It is definite, though, that Q22 memory won't work with an LSI-11/2 > (M7270) ... I'll try an LSI-11 (M7264) tomorrow, make sure it's the > same; it and the LSI-11/2 are similar enough that it should, but it'd be > good to confirm it. Yes, it too won't work with Q22 memory (tried it, no go - ODT won't even start). > Then back to trying to work out why Mini-Unix is so fragile for me. I tried some changes in the simulator set-up, to see if that would fix my issue; no luck. It's quite problematic: if I boot Mini-Unix on a clean copy of the RK pack, cd to /usr/sys/dev, cp kl.c to nkl.c, and 'cc -c nlk.c', Mini-Unix reliably restarts (trashing the disk in the process). (If I omit the 'cp', I can 'cc -c kl.c' 3 times, and Mini-Unix restarts on the third.) Something's seriously wrong. I think before I try debugging it directly, I'll try one of the other Mini-Unix repositories; the one I've been using (from Bob Eager's site) may have some bit-rot. > From: Paul Riley <paul(a)rileyriot.com> > I'm checking with Peter Schranz about whether or not his RLV12/RL02 > boards can run on the '03. Dave Bridgham and I discussed whether the QSIC would work with an -11/03, and that analysis should apply equally to the RLV12. Our conclusion was that it should; here's our reasoning: The device registers on the board should work fine on either Q18 or Q22. That's because when going to the I/O page, the CPU asserts a special bus line, BBS7 (that says 'this cycle is to the I/O page'). The device doesn't look at the higher address lines when that's on, just BDAL00-12; so if the LSI-11 is messing with some of BDAL181-21, it shouldn't matter. For DMA cycles from the device to memory, since the CPU requires Q18 memory to work, the device too should be able to read/write to Q18 memory. At least, that's our theory. I guess all this PDP-11 hardware detail isn't really on-topic for this list; I should move it to Classic Computers, or something. Sorry all; it's intermingled with early Unix stuff, and it was easier to keep it all in one place. Noel

3 years, 6 months

Re: [TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems

by jnc＠mercury.lcs.mit.edu

> From: Paul Riley > Can you clarify something for me regarding memory? I understand the > bottom area of memory in a Unix system is for the Kernel and it's stuff, > and that the top 8kB is set aside for device I/O Well, technically, the top 8KB of _address space_, not of memory - it's mostly used for device registers, etc. Here: http://gunkies.org/wiki/Unix_V6_kernel_memory_layout is a bit more detail on how the memory is laid out. > The LSI-11 board has 4kW of RAM on it, and I have already a 16KW > board. If I want to further expand the RAM, and say I buy another 16kW > board, that makes an arithmetic sum of 32kW for the boards, making 36kW > total. Can the 4kW of on-board RAM be disabled, and only the 32kW on > the boards be used? Yeah, if you look at LSI-11 documentation, there are jumpers that allow configuration of the on-board memory. Depending on the etch revision; for my F revision, jumper W11 (at the top, towards the handle edge, in the middle of that edge; just below the W1/W2 jumper pair) should be out to disable the on-board memory. Or you could configure the two 32KB boards to be at 020000 and 0120000; there will be 72KB of memory total on the QBUS, but the LSI-11 CPU (no memory management) will only be able to 'see' the bottom 56KB. > Is it ok for the installed RA mto overlap the 8kW at the high memory > area? Yeah, what the CPU sees as the I/O page (at 0160000-0177776 in its address space) is actually at 0760000-0777776 on the QBUS (on a Q18 QBUS); the CPU automagically translates the 0160000-0177776 addresses up. On a PDP-11 with memory management, the MMU has to be set up to do that. E.g. in V6, in: https://minnie.tuhs.org//cgi-bin/utree.pl?file=V6/usr/sys/conf/m40.s there is the following code: / initialize io segment mov $IO,(r0)+ mov $77406,(r1)+ / rw 4k to set the I/O page in kernel address space to point to the I/O page on the bus. Noel

3 years, 6 months

Re: [TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems

by jnc＠mercury.lcs.mit.edu

> From: Pete Turnbull > The SRUNL signal that was mentioned isn't likely to cause a problem That was just a guess on my part as to the exact cause. It is definite, though, that Q22 memory won't work with an LSI-11/2 (M7270); I just tried it. I didn't touch any of the other boards; just swapped the LSI-11/2 for a KDF11-A (M8186), everything worked fine; put the LSI-11/2 back, dead again. I'll try an LSI-11 (M7264) tomorrow, make sure it's the same; it and the LSI-11/2 are similar enough that it should, but it'd be good to confirm it. Then back to trying to work out why Mini-Unix is so fragile for me. Has anyone else ever worked with Mini-Unix, and if so, any tips? Noel

3 years, 6 months

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TUHS September 2020