[Simh] pdp11 and unix
Robert Thomas
rft at asthomas.com
Mon Feb 29 12:37:19 EST 2016
My first programming experience was on an IBM 1620. I had a chance to write very simple programs in GOTRAN (an early FORTRAN that ran on the 1620). My mother was in charge of the company's computational facilities. Prior to the 1620 they had an IBM 730 (?) that was programmed via wiring boards. Those early computers were slow, but for complex scientific calculations freed research engineers from performing those calculations. 24 to 48 hour program runs were common. We used to watch the address and data lights on the console to see if the program was caught in an infinite loop, and used the front panel switches to turn on and off diagnostic printouts. The 1620 was replaced by an IBM 1130 to be replaced by a PDP-11/20.
When I was in graduate school at Princeton in 1974, we used UNIX on a PDP-11/45 running Tex to typeset faculty papers, as well as writing compilers using lex and yacc and studying operating system and algorithm performance. Some graduate students over the summer ported UNIX to run on the IBM 370/195 in a virtual machine. There was a lot of activity going on that eventually escaped from academic labs into real commercial use.
I used to know by memory the bootstrap toggles for the PDP-8's and PDP-11/20, and then bootstrap the fan fold paper tape bootstrap on the ASR-33. Things that are forgotten and not missed.
Sincerely,
Robert F. Thomas
44 Industrial Way
Norwood, MA USA 02062
N Office Phone - (781) 329-9200
O mail to: rft at asthomas.com
-----Original Message-----
From: Simh [mailto:simh-bounces at trailing-edge.com] On Behalf Of simh-request at trailing-edge.com
Sent: Monday, February 29, 2016 12:00 PM
To: simh at trailing-edge.com
Subject: Simh Digest, Vol 145, Issue 121
Send Simh mailing list submissions to
simh at trailing-edge.com
To subscribe or unsubscribe via the World Wide Web, visit
http://mailman.trailing-edge.com/mailman/listinfo/simh
or, via email, send a message with subject or body 'help' to
simh-request at trailing-edge.com
You can reach the person managing the list at
simh-owner at trailing-edge.com
When replying, please edit your Subject line so it is more specific than "Re: Contents of Simh digest..."
Today's Topics:
1. Re: pdp11 and unix (Andreas Davour)
2. Re: Klh10 vs Simh (Peter Svensson)
3. Re: pdp11 and unix (Paul Koning)
----------------------------------------------------------------------
Message: 1
Date: Mon, 29 Feb 2016 09:38:36 +0100 (CET)
From: Andreas Davour <ante at Update.UU.SE>
To: lists at openmailbox.org
Cc: simh at trailing-edge.com
Subject: Re: [Simh] pdp11 and unix
Message-ID:
<alpine.DEB.2.02.1602290938080.6160 at Psilocybe.Update.UU.SE>
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
On Mon, 29 Feb 2016, lists at openmailbox.org wrote:
> On Mon, 29 Feb 2016 08:49:15 +0100 (CET) Andreas Davour
> <ante at Update.UU.SE> wrote:
>
>> "The over-all design of the LISP Programming System is the work of
>> John McCarthy and is based on his paper NRecursive Functions of
>> Symbolic Expressions and Their Computation by Machinett which was
>> published in Communications of the ACM, April 1960."
>>
>> So that timeframe is sound.
>
> It's interesting how many of the oldest languages are still in active
> use and still moving forwards after so many years. There seems to have
> been some kind of golden age of programming that started in late 1950s
> and went for about a decade.
Sometimes you get it right the first time. ;)
/andreas
--
"economics is a pseudoscience; the astrology of our time"
Kim Stanley Robinson
------------------------------
Message: 2
Date: Mon, 29 Feb 2016 11:22:51 +0100 (CET)
From: Peter Svensson <psvsimh at psv.nu>
To: TJ Merritt <simh at tj.merritts.org>
Cc: simh at trailing-edge.com
Subject: Re: [Simh] Klh10 vs Simh
Message-ID: <alpine.LRH.2.20.1602291116240.8740 at cheetah.psv.nu>
Content-Type: text/plain; charset=US-ASCII; format=flowed
Hi,
I think that most cards under both Linux and Windows ( >= 7) can support more than one association and thus can support simulated devices with their own 802.3 source MAC address. Windows supports attaching several times via their WiFi virtual MiniPort driver and Linux supports them for most cards via the 'iw' command to add more interfaces. But 4-address mode is nicer, for sure. :-)
Most low-cost APs support 4-address mode (a.k.a. WDS), wither natively or by loading a better firmware (I use OpenWRT). But 4-address mode is not strictly needed if the simulation can make do with only one source 802.3 MAC address.
Peter
On Sun, 28 Feb 2016, TJ Merritt wrote:
> https://www.safaribooksonline.com/library/view/80211-wireless-networks
> /0596100523/ch04.html
>
> This provides some nice graphics for different topologies. For
> bridging to work (aka the simh), the WDS case is required. Most
> consumer wifi for mobile devices figure that they only have to support
> their own MAC address and do not support WDS correctly. That is why
> SimH on your laptop cannot tunnel packets sent over WiFi. It's out
> going packets go out to the AP in infrastructure mode (Fig. 4-10).
> The RA is the Mac address of the base station, SA is the MAC address
> of the laptop, and DA is the dest. address from the tap/tun interfaces ethernet frame. Note that the source address
> from the frame has now been dropped. The Reply packet to SimH will be
> received by the laptop (Fig. 4-9) with DA set to the MAC address of
> the laptop's WiFi interface, TA set to the base stations Mac Address,
> and SA set to the source address from the original ethernet frame.
> Note that the SimH MAC address is not included, so the frame will not be bridged to the tap/tun
> interface and seen by SimH. If WDS is used, then you can still have issues
> with base stations not processing the frames correctly. Higher end
> WiFi access points generally work correctly, but it doesn't help you
> run SimH on your laptop with a consumer grade WiFi interface. Any
> easy way to see what is happening in your configuration is to run
> tcpdump on the wifi interface of your laptop. You will likely see the
> frames that should go to SImH being received by the laptop, but the
> destination ethernet address will be that of the laptop not that of
> the SimH tap/run interface. Your host OS won't know what to do with them, and they will be dropped by your laptop.
>
> On 02/28/2016 05:28 AM, Johnny Billquist wrote:
>> I must admit that my WiFi knowledge is a bit sketchy, but on the
>> other hand do I think that I know ethernet...
>>
>> But reading up on 802.11, I don't see what you mean by 802.1. I'm
>> not even sure what 802.1 actually says.
>>
>> However, 802.11 uses 802.2 for packets, which is unlike ethernet,
>> which is not an 802 protocol at all.
>>
>> Also, reading up on 802.11, it appears that source and destination
>> MAC address are always present. However, there are potentially two
>> more MAC addresses in the packet, which I have not found much good
>> information about yet. Wikipedia suggest the third is for filtering
>> purposes, and do not even explain the fourth one.
>>
>> What I do know, from observation, is that if I have something like
>> simh setup to communicate over WiFi, packets do get sent out, but my
>> simh instance will not receive any unicast packets to it, which
>> suggests that the switch do not send such packets out over WiFi to
>> the correct destination. I would assume it is because switches knows
>> which stations actually do exist, but that is a guess on my part.
>>
>> Johnny
>>
>> On 2016-02-28 07:29, Peter Svensson wrote:
>> > Hi all,
>> >
>> > The answers given last time were not all that accurate. WiFi for
>> > historical reasons conserve bandwidth by assuming that the client
>> > side
>> > 802.11 mac address is the same as the 802.1 sender mac address and
>> > thus omits the latter. This is the so called 3-address mode. This
>> > does not leave any room for more than one 802.1 mac address on a client.
>> >
>> > However, there is also a 4 address mode for WiFi which does
>> > support bridging since the 802.1 frames are transported verbatim.
>> > This mode has many different names from vendors. Most commonly it
>> > goes by the name WDS, but that name is unfortunately also used by
>> > a bunch of non transparent mechanisms from other vendors.
>> >
>> > See e.g. http://linuxwireless.org/en/users/Documentation/iw/
>> >
>> > 802.11 does not care about broadcast one way or another. It is
>> > just transported. It does not care what layer 3 is used (except
>> > only one layer 2 sec address in 3 address mode).
>> >
>> > The decision to save 6 bytes is an unfortunate historical
>> > artefact. The
>> > (802.11 standard) option to not save these bytes is not always
>> > exposed on wifi equipment. Some does, and most can I'd you run
>> > OpenWrt or similar software on them. Not sure about Windows though.
>> >
>> > Peter
>> >
>> > On February 27, 2016 11:01:31 PM GMT+01:00, Johnny Billquist
>> > <bqt at softjar.se> wrote:
>> >
>> > On 2016-02-27 20:14, Andreas Davour wrote:
>> >
>> > On Sat, 27 Feb 2016, Johnny Billquist wrote:
>> >
>> > On 2016-02-27 17:53, Michael Kerpan wrote:
>> >
>> > It's not that multiuser is impossible using KLH10
>> > networking emulation
>> > and native TOPS-20 TCP/IP, it's that it's a lot harder
>> > to set up than a
>> > SIMH virtual multiplexer. Wifi (under Linux at least)
>> > doesn't play all
>> > that well with bridging and virtual networking stuff,
>> > which makes
>> > setting up networking in KLH10 nigh impossible for those
>> > of us stuck on
>> > wireless. I can't even really set up a VM and run KLH10
>> > in a guest,
>> > because Virtualbox's bridged mode doesn't work for me.
>> > Additionally, the
>> > idea of putting anything running a 30 year old TCP/IP
>> > stack onto the
>> > Internet scares me, even if the folks at twenex.org
>> > <http://twenex.org> <http://twenex.org>
>> > have done so.
>> >
>> >
>> > The WiFi problem is easy to solve. It's called a router.
>> > Your host
>> > routes IP between the WiFi interface and the virtual network
>> > the host
>> > and your virtual machine shares.
>> >
>> > Trouble setting up networking on the virtual machine? Maybe.
>> > But this
>> > boils down to - if you want to run that host, you should
>> > learn how to
>> > manage it.
>> >
>> > Security issues are mostly non-issues. How many script
>> > kiddies today
>> > even know what a TOPS-20 host is. There are most certainly
>> > vulnerabilities, but they are very different from the ones
>> > presented
>> > by modern machines.
>> >
>> > I have an RSX system on the Internet, and it gets constant
>> > probing
>> > over telnet and http, but they are all probing in ways that
>> > just don't
>> > make sense. So I have never felt more secure.
>> >
>> >
>> > To Johnnys suggestions I might add that (I don't know
>> > exactly what
>> > problems you're having) maybe openvswitch might help out?
>> >
>> >
>> > The problem is that WiFi is not really like ethernet (I think
>> > we covered
>> > this a month ago, but maybe it was on a different list).
>> > Anyway, if you
>> > have a simh instance using WiFi for the network, it do not
>> > work, since
>> > putting the interface in promiscuous mode, and pretend you
>> > have a second
>> > machine with a different MAC address do not work, since with
>> > WiFi, the
>> > base station actually knows which MAC addresses are connected,
>> > and if a
>> > packet comes in for a device for which the MAC address is not
>> > registered, the packet will not be send out over WiFi, so you
>> > will not
>> > get anything, even though you think you have your
>> > interface in
>> > promiscuous mode, and are sending packets out with a different
>> > source
>> > MAC address, which you might think the WiFi switch would
>> > learn, as it
>> > would had it been ethernet.
>> >
>> > Johnny
>> >
>>
>>
>
> _______________________________________________
> Simh mailing list
> Simh at trailing-edge.com
> http://mailman.trailing-edge.com/mailman/listinfo/simh
>
Peter
--
Peter Svensson ! Pgp key available by finger, fingerprint:
<petersv at psv.nu> ! 8A E9 20 98 C1 FF 43 E3 07 FD B9 0A 80 72 70 AF
------------------------------------------------------------------------
Remember, Luke, your source will be with you... always...
------------------------------
Message: 3
Date: Mon, 29 Feb 2016 10:23:15 -0500
From: Paul Koning <paulkoning at comcast.net>
To: lists at openmailbox.org
Cc: simh at trailing-edge.com
Subject: Re: [Simh] pdp11 and unix
Message-ID: <2EACAA6C-BAC8-42E6-A6DB-81AFFF48F846 at comcast.net>
Content-Type: text/plain; charset=us-ascii
> On Feb 29, 2016, at 1:21 AM, lists at openmailbox.org wrote:
>
> On Sat, 27 Feb 2016 17:32:19 -0500
> Paul Koning <paulkoning at comcast.net> wrote:
>
>> Decimal did show up at times even into the 1960s, for example in the
>> IBM 1620. But it never made all that much sense; converting between
>> binary and decimal is quite easy even in those very old machines.
>> The one plausible application area is business data processing where
>> the arithmetic is trivial and most of the work is I/O or other
>> non-arithmetic operations.
>
> IBM S/360 (1964) and follow-ons have all had hardware support for
> decimal and COBOL and PL/I on these platforms have always had native
> suport for the data type.
>
> As you might expect decimal arithmetic is used extensively in
> financial transactions and reporting since there is no problem of
> conversion. Money can be represented exactly rather than approximately
> as with floating point. Most banks still run their financial
> transactions on IBM hardware and OS for that reason among others.
Most 360s, actually; the 360 model 44 didn't have decimal instructions (except via an emulator -- like the later microVAXen with their subset instruction sets).
I wasn't referring to packed decimal instructions for binary machines; those stayed around for a long time. Even VAX had them, at least originally. I was talking about decimal machines, with memories organized in decimal digits. The last computer I can think of that fits that description is the IBM 1620, from the early 1960s.
paul
------------------------------
Subject: Digest Footer
_______________________________________________
Simh mailing list
Simh at trailing-edge.com
http://mailman.trailing-edge.com/mailman/listinfo/simh
------------------------------
End of Simh Digest, Vol 145, Issue 121
**************************************
More information about the Simh
mailing list