TUHS

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Re: [TUHS] Unix NCP protocol stack for ARPANET

by jnc＠mercury.lcs.mit.edu

> From: "Ron Natalie" > However, the last NCP host table shows this statistic for DEC machines > on the NCP Arpanet > ... > PDP11 (MOS): 11 > PDP11 (MINITS); 10 Hi, which host table was this that you're looking at? I'm pretty sure there was no MINITS NCP ('NCP' in the sense of 'Initial Connection Protocol (ICP)' and 'ARPANET Host-to-Host Protocol (AHHP)' - see below). There was _certainaly_ no MINITS machine on the ARPANET at MIT (the birthplace of MINITS). To confirm, I looked at a major MINITS source repository, here: https://github.com/PDP-10/its/tree/master/src/mits_s and saw nothing like that. (Not even an 1822 interface driver.) If you look there, you _will_ see things labelled 'NCP', but this is just a terminological affliction among the CHAOS people, to whom 'NCP' apparently meant 'protocol implementation' or 'network code'. Also, implementations of the 'Host-to-IMP Protocol (HIP)' are _not_ NCP either; there was an HIP implementation in the C Gateway, but that was as IP router, one that could connect to an IMP. IF IT DOESN'T HAVE AHHP, IT"S NOT NCP. Also, I was intimately familiar with MOS, and neither of the two earliest applications that ran on it (the TIU, and the Port Expander, both of which I have the source code for) had any NCP. I looked at a lot of the MOS 'NCP" listings in a old host table (see here: https://gunkies.org/wiki/Talk:Network_Control_Program for details) and concluded that the MOS 'NCP' entries were all 'confused'. > From: Clem Cole > I was under the impression, that you folks at MIT did a ChaosNet > interface, IIRC, so there may have been some sort of conversion on > your LAN, but I really doubt there was a real NCP running. The AI Lab did both i) a LAN called CHAOS (4 Mbit/seccond CSMA-CD over CATV cable) and ii) a protocol family callled CHAOS (which later ran over XDI Ethernet). I'm not sure that any of it has any relvance to what's under discussion here. > But there was a Rand stack around the same time and III think > Holmgren ended up at UCSB after his time at UICI. Im fairly sure there > was cross polinartion but I don't know how much. I looked through my V6 Unix NCP, but although there were some RAND #ifdefs, I didn't see anything about Rand (except that the MMDF is noted as being based on something done at Rand). I retain the distinct impression that all V6 Unix NCP machines were running some descendant of the UIUC code. NOSC seems to have served as a distro center at one point, see: https://minnie.tuhs.org//cgi-bin/utree.pl?file=SRI-NOSC/new/dist.log but I can't tell who they were sending it too. (We never tried to get it running at MIT since we were out of IMP ports. By the time we got another IMP, we had IP running on the -11 and NCP was done anyway.) As for UCB, there are a bunch of UCBUFMOD #ifdef's, not sure what that was about. > As for other NCPs, PARC had MAXC on the net, but I thought it had > originally a DG Nova front end that was replaced with an Alto. No, Maxc1 had a Nova, Maxc2 had an Alto. > From: Paul Ruizendaal > they started with 32V in the Fall of 1979, and ported UIUC's NCP code > to it Thanks for straightening that out. I had a vague memory that there were a few VAXen that ran NCP, but wasn't sure. > 2. Note that the BBN TCP worked over NCP as its primary transport. Your terminology is confused. TCP _never_ ran 'on' NCP; they were _alternative_ protocol stacks on top of IHP (on the ARPANET). No AHHP, no NCP. > The driver is still there if you look That acc.c is a driver for the ACC 1822 interface; it includes bits of IHP ("Try to send 3 no-ops to IMP") but I don't think it includes the complete IHP. There are other BSD 1822 device drivers, e.g.: https://minnie.tuhs.org/cgi-bin/utree.pl?file=2.11BSD/sys/pdpif/if_sri.c That's the BSD2.11 Stanford/SRI 1822 device driver. Noel

3 years, 6 months

Anyone have a modem wired up?

by John Floren

I'm experimenting with my PiDP-11; I think I may have my modem set up properly to accept incoming calls, but with only one phone line I'm unable to test it. If anyone with a modem is willing to help me test, send me a message off-list and I'll give you my phone number & some login details. john

3 years, 6 months

Motorola System V/68 preservation?

by Chris Hanson

Has anyone other than the owner of m88k.com preserved Motorola System V/68? Besides that, there’s the SVR1 (v2.8) for the Motorola VME/10 on Bitsavers and that’s about it. I’m especially curious as to whether anyone has preserved the SVR2 1.1 binary+sources distribution, since there might be useful information in it—or derivable from it—about much of the early VME hardware. — Chris Sent from my iPad

3 years, 6 months

Re: [TUHS] Unix NCP protocol stack for ARPANET

by Paul Ruizendaal

Noel wrote: >> 2. Note that the BBN TCP worked over NCP as its primary transport. > > Your terminology is confused. TCP _never_ ran 'on' NCP; they were > _alternative_ protocol stacks on top of IHP (on the ARPANET). No > AHHP, no NCP. Yes, of course you are right. I meant BBN TCP used *Arpanet* as its primary transport and hence has drivers for the IMP interface hardware. Lars wrote: > Here's the rub. Some hosts may have jumped the TCP/IP gun ahead of the > 1/1 1983 flag day. The host tables don't say. Could it be that all > those VAXen were running experimental TCP/IP in January 1982? From Mike Muuss’ TCP digest mailing list and a mail conversation with Vint Cerf a few years ago I understood the following. “Flag day” wasn’t as black and white as we remember it now. During 1982 there was a continuous push to move systems to TCP, and over the year more and more systems became dual protocol capable and later even TCP only. Because all TCP traffic used the same, dedicated Arpanet link number, BBN’s network control team could monitor the level of usage. From memory, in the Summer of 1982 traffic was about 50% TCP and by October 70%. Presumably it reached 80-90% by the end of the year. During 1982 on 3 occasions, network control activated a feature in the IMP’s that refused traffic on link #0, which NCP used to negotiate a connection. This caused NCP applications to stop working. Again from memory, the first outage was a few hours, the second one a day and third one, late in 1982, for two days. This highlighted systems that needed conversion and helped motivate higher ups to approve conversion resources. It seems that making the switch often involved upgrading PDP11 to VAX. From what I can tell flag day went well, although there were issues with mail gateways that lasted for several weeks. At the start of 1982 there was no (usable) VAX Unix TCP code that I am aware of. There were several options for the PDP11, but of those I think only the 3COM code worked well. Around March/April there was code from BBN (see TUHS 4.1BSD) and from CSRG (4.1a BSD). A special build of PDP11 2.8BSD with TCP arrived somewhat later. My impression is that this was still the state of play on flag day, with 4.1cBSD only arriving well into 1983.

3 years, 6 months

Re: [TUHS] Unix NCP protocol stack for ARPANET

by Paul Ruizendaal

> I have searched the TUHS archive and elsewhere, but all I > find for Unix is a copy of the PDP-11 Unix V6 NCP from Illinois. > > Has any other NCP implementation for Unix survived? From old host > tables I think there may have been some VAXen online before the switch > to TCP/IP. Lars, You may want to look at the 4 surviving BBN tapes on Kirk McKusick’s DVD software collection. A small part of that is on the TUHS Unix tree page - see the 4.1BSD entry. 1. A history of NCP on the VAX at BBN can be found in the change log: https://www.tuhs.org/cgi-bin/utree.pl?file=BBN-Vax-TCP/history In short they started with 32V in the Fall of 1979, and ported UIUC’s NCP code to it in May 1980. They then moved to 4.1BSD in August and ported yet again. It would seem that the ports were fairly straightforward. Coding for TCP begins in January 1981. 2. Note that the BBN TCP worked over NCP as its primary transport. The driver is still there if you look through the surviving BBN tapes. Part of that code is on TUHS: https://www.tuhs.org/cgi-bin/utree.pl?file=BBN-Vax-TCP/dev/acc.c https://www.tuhs.org/cgi-bin/utree.pl?file=BBN-Vax-TCP/bbnnet-oct82/imp_io.c It will take some effort, but probably the NCP VAX code can be reconstructed from the surviving PDP11 UIUC code and these BBN tapes (the file names in the change log match). 3. The BBN tapes also have some user level software: telnet, ftp, mtp. This code consists of straight NCP to TCP conversions and the source code has #ifdef’s for NCP and TCP. An example is here: https://www.tuhs.org/cgi-bin/utree.pl?file=BBN-Vax-TCP/src/telnet/netser.c Hope this helps. Paul PS - Info on the DVD is here (bottom of the page): https://www.mckusick.com/csrg/

3 years, 6 months

Unix NCP protocol stack for ARPANET

by Lars Brinkhoff

Hello, I'm working on setting up an emulated ARPANET using the original IMP software recovered some years ago. It turns out, the greatest challenge is finding the NCP software on the host side that implements the ARPANET protocols. I have searched the TUHS archive and elsewhere, but all I find for Unix is a copy of the PDP-11 Unix V6 NCP from Illinois. Has any other NCP implementation for Unix survived? From old host tables I think there may have been some VAXen online before the switch to TCP/IP. Best regards, Lars Brinkhoff

3 years, 6 months

having issues with simh and setting up dci for unixV7

by joseph turco

hello all, i am a new unix user, so please excuse my ignorance. I am trying to setup using unixV7 with simh pdp11 emulator. The guide i am following is by Will Senn (in PDF form). I have been able to successfully get the machine to boot with unix, and login as root. what i am having problems with, is trying to get telnet access via dci to work. when i follow the guide and do the following: # cd /usr/sys/conf # rm l.o c.o # cp hptmconf myconfnf # echo 4dc >> myconf # mkconf < myconf # make as - -o l.o l.s cc -c c.c ld -o unix -X -i l.o mch.o c.o ../sys/LIB1 ../dev/LIB2 # sum unix 10314 106 # ls -l unix -rwxrwxr-x 1 root 54122 Dec 31 19:09 unix etc... when i issue the mkconf < myconf command, i get a bunch of text printed out, but with a 'root device not found'. the sum unix value is different, as well as the size of the ls -l unix file size.. now when i try booting it with the newly created mboot.ini file (as per the guide), i go to start up the system with 'hp(0,0)munix' and it starts but hangs with the text 'fault devtab' what am I doing wrong? regards, Joseph Turco

3 years, 6 months

Minix 1.5 updates/patches?

by Chris Hanson

I’ve gotten Minix 1.5 up and running on Hatari, the Atari ST emulator, and I’d like to update it to the latest in the 1.5 series (1.5.10.7). The patch sets used to be quite readily available, but the only patch sets I’ve been able to find have been the 1.5.10.3 to 1.5.10.4 patches posted to Usenet (via minnie, thanks!) which won’t apply cleanly to my sources because I’m only running 1.5. (I know about the 1.6.25-on-Atari efforts, I’m trying to do something different and also fill in some git history…) — Chris

3 years, 7 months

mmap origin (was Systematic approach to command-line interfaces)

by Paul Ruizendaal

On Wed, Sep 29, 2021 at 09:40:23AM -0700, Greg A. Woods wrote: > I think perhaps the problem was that mmap() came too soon in a narrow > sub-set of the Unix implementations that were around at the time, when > many couldn't support it well (especially on 32-bit systems -- it really > only becomes universally useful with either segments or 64-bit and > larger address spaces). The fracturing of "unix" standards at the time > didn't help either. > > Perhaps these "add-on hack" problems are the reason so many people think > fondly of the good old Unix versions where everything was still coming > from a few good minds that could work together to build a cohesive > design. The add-ons were poorly done, not widely implemented, and > usually incompatible with each other when they were adopted by > additional implementations. mmap() did come from those days and minds. The first appearance of mmap() was in 32V R3, done by John Reiser in 1981. This is the version of 32V with full demand paging; it implemented a unified buffer cache. According to John, that version of mmap() already had the modern 6 argument API. John added mmap() because he worked with Tenex a lot during his PhD days and missed PMAP. He needed some 6 months to design, implement and debug this version of 32V as a skunkworks project. I am trying to revert early VAX SVr1/r2 code to get a better view of what 32V R3 looked like, but unfortunately I did not have much time for this effort in last couple of months. It would seem that 32V R3 assumed that disk blocks and memory pages were the same size (true on a 1980 VAX) and with that assumption a unified buffer cache comes natural in this code base. For 4.2BSD initially Joy cs. had a different approach to memory mapped files in mind (see the 1981 tech report #4 from CSRG). By the time of 4.2BSD’s release the manual defined a mmap() system call, but it was not implemented and it appears to have been largely forgotten until SunOS 4 and dynamic libraries six years later. In the SysV lineage it is less clear. For sure mmap() is not there, but the first implementation of the shmem IPC feature might derive from the 32V R3 code. On the inside, SVr2 virtual memory appears to implement the segments (now called regions) that Joy envisaged for 4.2BSD but did not implement. CB Unix had a precursor to shmem as well, where a portion of system core was reserved for shared memory purposes and could be accessed either via the /dev/mem device or could be mapped into the PDP-11 address space (using 1 of the 8 segment registers for each map). Here too the device and the map were unified. So far, I have not come across any shared library implementations or precursors in early Unix prior to SunOS 4. Paul

3 years, 7 months

IEEE Annals on the History of Computing seeks Editor in Chief

by Diomidis Spinellis

Dear TUHS members, The IEEE Annals on the History of Computing magazine, the primary publication for recording, analyzing, and debating the history of computing, is seeking a new Editor in Chief [2]. The EiC term begins on January 1st 2022 and is for three years, renewable for two years. The application deadline is October 31st 2021. It would be valuable for us interested in our discipline's history to to serve in the publication's leadership. You can contact Carrie Clark at c.clark(a)computer.org to submit an application. Alternatively, if you have connections in the community and some time to spare to head the EiC selection committee, please drop me a note. [1] https://www.computer.org/csdl/magazine/an [2] https://www.computer.org/press-room/2021-news/ieee-cs-publications-seek-app… Kind regards, Diomidis Spinellis

3 years, 7 months

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