* [TUHS] off-topic: resurrecting the IMP
@ 2013-12-01 21:18 Aharon Robbins
2013-12-01 21:42 ` Ronald Natalie
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Aharon Robbins @ 2013-12-01 21:18 UTC (permalink / raw)
Hi all.
This may be of some interest. From a friend at Utah:
> Date: Sat, 30 Nov 2013 16:06:25 -0700 (MST)
> Subject: [it-professionals] computer history: Arpanet IMPs resurrected
>
> The simh list about simulators for early computers recently carried
> traffic about an effort to reconstruct and resurrect the Arpanet
> Interface Message Processors (IMPs), which were the network boxes that
> connected hosts on the early Arpanet, which later became the Internet.
>
> There is a draft of a paper about the work here:
>
> The ARPANET IMP Program: Retrospective and Resurrection
> http://walden-family.com/bbn/imp-code.pdf
>
> Utah was one of the original gang-of-five hosts on the Arpanet, and we
> received IMP number 4. Utah is mentioned twice in the article, and
> also appears in the map in Figure 3 on page 14.
>
> One amusing remark in the article (bottom of page 7) has to do with
> the fail-safe design of the IMPs:
>
> In addition ``reliability code'' was developed to allow a
> Pluribus IMP to keep functioning as a packet switch in the
> face of various bits of its hardware failing, such as a
> processor or memory [Katsuki78, Walden11 pp. 534-538]. This
> was so successful there was no simple off switch for the
> machine; a program had to be run to shut parts of the machine
> down faster than the machine could ``fix itself'' and keep
> running.
>
> As happened with early Unix releases, machine-readable code for the
> IMPs was lost, but fortunately, some old listings that turned up
> recently allowed its laborious reconstruction, verification, assembly,
> and simulation.
Arnold
^ permalink raw reply [flat|nested] 6+ messages in thread
* [TUHS] off-topic: resurrecting the IMP
2013-12-01 21:18 [TUHS] off-topic: resurrecting the IMP Aharon Robbins
@ 2013-12-01 21:42 ` Ronald Natalie
2013-12-01 22:54 ` Armando Stettner
2013-12-02 12:21 ` random832
2 siblings, 0 replies; 6+ messages in thread
From: Ronald Natalie @ 2013-12-01 21:42 UTC (permalink / raw)
Cool. I have fond memories of the IMPs. We got to put our first UNIX machine on the Arpanet at BRL when they changed to long leaders and it seemed that the ANTS (an 11/40 based terminal service) could not be upgraded to support it. We had another fire drill on the TCP/IP changeover, and again on the ARPANET MILNET split (which I finally convinced people in authority to STOP MAKING THESE MAJOR CHANGES ON JANUARY 1, I was tired of spending my holidays dealing with network protocol changes).
I actually had 4 C-30 based imps that was the core of our own campus network at BRL. I even wrote our own NOC code. I got a nice email from BBN when I told them I had our systems operational shortly after the hardware rep from BBN plugged them in (I had the Bell 303 modems ready to go) explaining how it was not possible for me to have done that.
I wrote back and told him that I was sure glad I didn't know it was impossible before I did it. Might have discouraged me.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [TUHS] off-topic: resurrecting the IMP
2013-12-01 21:18 [TUHS] off-topic: resurrecting the IMP Aharon Robbins
2013-12-01 21:42 ` Ronald Natalie
@ 2013-12-01 22:54 ` Armando Stettner
2013-12-02 14:36 ` Clem Cole
2013-12-02 12:21 ` random832
2 siblings, 1 reply; 6+ messages in thread
From: Armando Stettner @ 2013-12-01 22:54 UTC (permalink / raw)
THIS IS SO COOL!!
aps at dec-marlboro
aps at rand-ai
Begin forwarded message:
> From: Aharon Robbins <arnold at skeeve.com>
> Subject: [TUHS] off-topic: resurrecting the IMP
> Date: December 1, 2013 1:18:26 PM PST
> To: tuhs at tuhs.org
>
> Hi all.
>
> This may be of some interest. From a friend at Utah:
>
>> Date: Sat, 30 Nov 2013 16:06:25 -0700 (MST)
>> Subject: [it-professionals] computer history: Arpanet IMPs resurrected
>>
>> The simh list about simulators for early computers recently carried
>> traffic about an effort to reconstruct and resurrect the Arpanet
>> Interface Message Processors (IMPs), which were the network boxes that
>> connected hosts on the early Arpanet, which later became the Internet.
>>
>> There is a draft of a paper about the work here:
>>
>> The ARPANET IMP Program: Retrospective and Resurrection
>> http://walden-family.com/bbn/imp-code.pdf
>>
>> Utah was one of the original gang-of-five hosts on the Arpanet, and we
>> received IMP number 4. Utah is mentioned twice in the article, and
>> also appears in the map in Figure 3 on page 14.
>>
>> One amusing remark in the article (bottom of page 7) has to do with
>> the fail-safe design of the IMPs:
>>
>> In addition ``reliability code'' was developed to allow a
>> Pluribus IMP to keep functioning as a packet switch in the
>> face of various bits of its hardware failing, such as a
>> processor or memory [Katsuki78, Walden11 pp. 534-538]. This
>> was so successful there was no simple off switch for the
>> machine; a program had to be run to shut parts of the machine
>> down faster than the machine could ``fix itself'' and keep
>> running.
>>
>> As happened with early Unix releases, machine-readable code for the
>> IMPs was lost, but fortunately, some old listings that turned up
>> recently allowed its laborious reconstruction, verification, assembly,
>> and simulation.
>
> Arnold
> _______________________________________________
> TUHS mailing list
> TUHS at minnie.tuhs.org
> https://minnie.tuhs.org/mailman/listinfo/tuhs
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [TUHS] off-topic: resurrecting the IMP
2013-12-01 21:18 [TUHS] off-topic: resurrecting the IMP Aharon Robbins
2013-12-01 21:42 ` Ronald Natalie
2013-12-01 22:54 ` Armando Stettner
@ 2013-12-02 12:21 ` random832
2 siblings, 0 replies; 6+ messages in thread
From: random832 @ 2013-12-02 12:21 UTC (permalink / raw)
On Sun, Dec 1, 2013, at 16:18, Aharon Robbins wrote:
> > In addition ``reliability code'' was developed to allow a
> > Pluribus IMP to keep functioning as a packet switch in the
> > face of various bits of its hardware failing, such as a
> > processor or memory [Katsuki78, Walden11 pp. 534-538]. This
> > was so successful there was no simple off switch for the
> > machine; a program had to be run to shut parts of the machine
> > down faster than the machine could ``fix itself'' and keep
> > running.
So, I'm not old enough to know anything about this era... I have a
question.
If these things were so reliable, why couldn't they be shut down by
simply cutting power to everything at once?
^ permalink raw reply [flat|nested] 6+ messages in thread
* [TUHS] off-topic: resurrecting the IMP
2013-12-01 22:54 ` Armando Stettner
@ 2013-12-02 14:36 ` Clem Cole
2013-12-02 15:51 ` Armando Stettner
0 siblings, 1 reply; 6+ messages in thread
From: Clem Cole @ 2013-12-02 14:36 UTC (permalink / raw)
+1
As for reliability. The CMU IMP at one time was near one of the big
printer from the PDP-10's and often became a temporary resting place for
something if you had to deal with a printer jam, change paper etc. I have
memories of the time a milkshake got knocked/spilled into the IMP in the
summer of 76 or 77. IIRC: somebody was smart enough to pull the breaker on
the power. Then placed a called to BBN and asked them what to do.
Somewhere I had a picture of a person ??Jim Teter maybe?? acting on the
response in the parking lot: hose it down and the use hair dryers to dry it
out.
It was powered back up and worked and soon appeared a sign about not
putting stuff on the IMP
On Sun, Dec 1, 2013 at 5:54 PM, Armando Stettner <aps at ieee.org> wrote:
> THIS IS SO COOL!!
>
> aps at dec-marlboro
> aps at rand-ai
>
>
> Begin forwarded message:
>
> > From: Aharon Robbins <arnold at skeeve.com>
> > Subject: [TUHS] off-topic: resurrecting the IMP
> > Date: December 1, 2013 1:18:26 PM PST
> > To: tuhs at tuhs.org
> >
> > Hi all.
> >
> > This may be of some interest. From a friend at Utah:
> >
> >> Date: Sat, 30 Nov 2013 16:06:25 -0700 (MST)
> >> Subject: [it-professionals] computer history: Arpanet IMPs resurrected
> >>
> >> The simh list about simulators for early computers recently carried
> >> traffic about an effort to reconstruct and resurrect the Arpanet
> >> Interface Message Processors (IMPs), which were the network boxes that
> >> connected hosts on the early Arpanet, which later became the Internet.
> >>
> >> There is a draft of a paper about the work here:
> >>
> >> The ARPANET IMP Program: Retrospective and Resurrection
> >> http://walden-family.com/bbn/imp-code.pdf
> >>
> >> Utah was one of the original gang-of-five hosts on the Arpanet, and we
> >> received IMP number 4. Utah is mentioned twice in the article, and
> >> also appears in the map in Figure 3 on page 14.
> >>
> >> One amusing remark in the article (bottom of page 7) has to do with
> >> the fail-safe design of the IMPs:
> >>
> >> In addition ``reliability code'' was developed to allow a
> >> Pluribus IMP to keep functioning as a packet switch in the
> >> face of various bits of its hardware failing, such as a
> >> processor or memory [Katsuki78, Walden11 pp. 534-538]. This
> >> was so successful there was no simple off switch for the
> >> machine; a program had to be run to shut parts of the machine
> >> down faster than the machine could ``fix itself'' and keep
> >> running.
> >>
> >> As happened with early Unix releases, machine-readable code for the
> >> IMPs was lost, but fortunately, some old listings that turned up
> >> recently allowed its laborious reconstruction, verification, assembly,
> >> and simulation.
> >
> > Arnold
> > _______________________________________________
> > TUHS mailing list
> > TUHS at minnie.tuhs.org
> > https://minnie.tuhs.org/mailman/listinfo/tuhs
> >
> _______________________________________________
> TUHS mailing list
> TUHS at minnie.tuhs.org
> https://minnie.tuhs.org/mailman/listinfo/tuhs
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://minnie.tuhs.org/pipermail/tuhs/attachments/20131202/70bbf18c/attachment.html>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [TUHS] off-topic: resurrecting the IMP
2013-12-02 14:36 ` Clem Cole
@ 2013-12-02 15:51 ` Armando Stettner
0 siblings, 0 replies; 6+ messages in thread
From: Armando Stettner @ 2013-12-02 15:51 UTC (permalink / raw)
Was that really BBN's advice? Pretty funny. :)
Of course, who knows how many cups of coffee were spilled by IBM printers when their tops would open up as a result of running out of paper....
aps
Begin forwarded message:
> From: Clem Cole <clemc at ccc.com>
> Subject: Re: [TUHS] off-topic: resurrecting the IMP
> Date: December 2, 2013 6:36:42 AM PST
> To: Armando Stettner <aps at ieee.org>
> Cc: Aharon Robbins <arnold at skeeve.com>, The Eunuchs Hysterical Society <tuhs at tuhs.org>, Daniel V Klein <dvk at lonewolf.com>
>
> +1
>
> As for reliability. The CMU IMP at one time was near one of the big printer from the PDP-10's and often became a temporary resting place for something if you had to deal with a printer jam, change paper etc. I have memories of the time a milkshake got knocked/spilled into the IMP in the summer of 76 or 77. IIRC: somebody was smart enough to pull the breaker on the power. Then placed a called to BBN and asked them what to do. Somewhere I had a picture of a person ??Jim Teter maybe?? acting on the response in the parking lot: hose it down and the use hair dryers to dry it out.
>
> It was powered back up and worked and soon appeared a sign about not putting stuff on the IMP
>
>
> On Sun, Dec 1, 2013 at 5:54 PM, Armando Stettner <aps at ieee.org> wrote:
> THIS IS SO COOL!!
>
> aps at dec-marlboro
> aps at rand-ai
>
>
> Begin forwarded message:
>
> > From: Aharon Robbins <arnold at skeeve.com>
> > Subject: [TUHS] off-topic: resurrecting the IMP
> > Date: December 1, 2013 1:18:26 PM PST
> > To: tuhs at tuhs.org
> >
> > Hi all.
> >
> > This may be of some interest. From a friend at Utah:
> >
> >> Date: Sat, 30 Nov 2013 16:06:25 -0700 (MST)
> >> Subject: [it-professionals] computer history: Arpanet IMPs resurrected
> >>
> >> The simh list about simulators for early computers recently carried
> >> traffic about an effort to reconstruct and resurrect the Arpanet
> >> Interface Message Processors (IMPs), which were the network boxes that
> >> connected hosts on the early Arpanet, which later became the Internet.
> >>
> >> There is a draft of a paper about the work here:
> >>
> >> The ARPANET IMP Program: Retrospective and Resurrection
> >> http://walden-family.com/bbn/imp-code.pdf
> >>
> >> Utah was one of the original gang-of-five hosts on the Arpanet, and we
> >> received IMP number 4. Utah is mentioned twice in the article, and
> >> also appears in the map in Figure 3 on page 14.
> >>
> >> One amusing remark in the article (bottom of page 7) has to do with
> >> the fail-safe design of the IMPs:
> >>
> >> In addition ``reliability code'' was developed to allow a
> >> Pluribus IMP to keep functioning as a packet switch in the
> >> face of various bits of its hardware failing, such as a
> >> processor or memory [Katsuki78, Walden11 pp. 534-538]. This
> >> was so successful there was no simple off switch for the
> >> machine; a program had to be run to shut parts of the machine
> >> down faster than the machine could ``fix itself'' and keep
> >> running.
> >>
> >> As happened with early Unix releases, machine-readable code for the
> >> IMPs was lost, but fortunately, some old listings that turned up
> >> recently allowed its laborious reconstruction, verification, assembly,
> >> and simulation.
> >
> > Arnold
> > _______________________________________________
> > TUHS mailing list
> > TUHS at minnie.tuhs.org
> > https://minnie.tuhs.org/mailman/listinfo/tuhs
> >
> _______________________________________________
> TUHS mailing list
> TUHS at minnie.tuhs.org
> https://minnie.tuhs.org/mailman/listinfo/tuhs
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-12-02 15:51 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-12-01 21:18 [TUHS] off-topic: resurrecting the IMP Aharon Robbins
2013-12-01 21:42 ` Ronald Natalie
2013-12-01 22:54 ` Armando Stettner
2013-12-02 14:36 ` Clem Cole
2013-12-02 15:51 ` Armando Stettner
2013-12-02 12:21 ` random832
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).