Now that we know the 10 was in HRC, it makes total sense and we're loving this part of the story. Right on the Drag, in a cool and interesting building with the History Collection there and the Art. Was Quackenbush's already there across the street on the Drag? Looking forward to learning how the move into HRC happened, who participated in that move, what was it like, who was there when the 10 was first installed, etc.
From: Noah Smith <Unknown>
Date: Sunday, January 25, 2026 at 4:38:14 PM UTC+1
Subject: Re: [pidp-10] Re: Join me, together we can rule the ARPANET
Hi Lars, we'd like to volunteer to adopt the utexas node as part DecwarOrg - suspect utexas was a bit after 1973 though, maybe around 1975 or so as a guess? fwiw, this below looks about right to me - so decwar.org node is a 'few years late':) but we'd love to be part of the story in whatever role!:)
1. Confusion with the "First Four" (1969) The "UT" in the original four ARPANET nodes refers to the University of Utah (Node 4), which was installed in December 1969. The other three originals were UCLA, SRI (Stanford Research Institute), and UC Santa Barbara.
2. Absence in Early Maps (1969–1974)1969–1973: UT Austin does not appear on ARPANET logical maps from this period. January 1974: A management study report from January 1974 explicitly noted that major commercial and research centers in "Texas are not" yet represented on the network, confirming that UT Austin was not yet connected at this time.
3. Installation and Connection (1975–1976) Appearance on Maps: The University of Texas (often labeled "Texas" or "UTEXAS" on logical maps) begins appearing on ARPANET maps between 1975 and 1977. Visual Confirmation: By the March 1977 logical map, "Texas" is clearly visible as a node, connected to the network alongside other expanding universities. Directory Evidence: The ARPANET Directory from 1978 lists the University of Texas at Austin (specifically the Linguistics Research Center and Computation Center) as a fully operational host.
Date: Sunday, January 25, 2026 at 5:43:01 PM UTC+1
Subject: Re: [pidp-10] Re: Join me, together we can rule the ARPANET
There's room for more than one ARPANET project. Oscar is mainly aiming for an around 1973 network with historical hosts, and run them all on a single machine. I my first idea, and how I started this thread, is to have a somewhat later vintage network operated by enthusiasts connecting their computers together. An question for you is whether UTEXAS ran TOPS-10 or TOPS-20? I have some vague impression DECWAR was more of a TOPS-10 thing, but maybe I have that wrong. If UTEXAS was a TOPS-10 shop, the bad news is that we haven't located an NCP for that operating system.
The IMP arrived on the UT campus in 1977 and was installed alongside the DEC-10 in the HRC. This was because originally there were hopes that the DEC-10 would become the first ARPANET host on the Texas node. But DEC never offered support for the ARPANET on the DEC-10’s standard OS, TOPS-10. The only DEC-10 OS's that supported a connection were TENEX (developed at BBN), ITS (the Incompatible Timesharing System at MIT), and several heavily customized versions of TOPS-10 at places like CMU, Harvard, and Wharton. The Stanford AI Lab ran WAITS (the West-coast Alternative to ITS) on their DEC-10s. So the DEC-10 in HRC was never connected to the ARPANET. Meanwhile, there was a PDP-11 running UNIX in the Daily Texan composing room at TSP (Texas Student Publications). A hacked version of UNIX from the U. of Illinois was installed, and the IMP was moved across campus to the Communications Building. Thus, a PDP-11/45 running UNIX became UTEXAS, the first ARPANET host on campus. The select few who knew about this would connect to the 11 via dialup modems and from there could venture out to the rest of the ARPANET.
ReplyDeleteSometime around 1978-80, a newer IMP was delivered by BBN and installed in the Computation Center. A PDP-11/70 was installed there to connect to the new IMP, and so the UTEXAS host was rehomed from TSP to the Comp. Center. It was only when the first DEC-20 arrived and was installed in Painter Hall that the PDP-11 became UTEXAS-11 and the 20 was named UTEXAS-20. As I recall, the 11 retained the host nickname of UTEXAS.
At about the same time, specialized research hardware was acquired by the Certifiable Minicomputer Project (CMP) for the purpose of providing secure encrypted communications. This required that a very thick cable with 32 twisted pairs of copper be run from the 21st floor of the tower, down the elevator shaft and through the steam tunnels to the Comp. Center, where it plugged into the IMP. When the CMP project was completed several years later and the hardware decommissioned, the cable was left in the elevator shaft, as it was not worth the trouble to remove it. I wonder if the folks currently remodeling the Tower have come across it?! (Hat tip to Rich Cohen and Clyde Hoover for filling in some details of this story.)
Fantastic info Clive, thank you so much for this! Am going to be rereading this many times to let it all sink in:) Was late myself and would only have been aware of these types of things from about 89 or 90 onward, but first thought is have a niggling suspicion that the names UTEXAS-11 and UTEXAS-20 feel somehow familiar, like maybe there's some buried memories of seeing those names...:)
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