by Darius Kazemi, September 11 2019
In 2019 I'm reading one RFC a day in chronological order starting from the very first one. More on this project here. There is a table of contents for all my RFC posts.
A handbook (and a time machine)
RFC-254 (PDF) is titled “Scenarios for Using ARPANET Computers”. It's authored by Abhay Bhushan of MIT Project MAC and dated October 29, 1971.
The technical content
This is a massive RFC, and I think it's massively important for readers of this blog.
If you've ever wanted to know what it was like to connect to the ARPANET, and what a typical user might actually be doing while logged into remote computers, this is basically your Rosetta Stone.
This RFC is an example of the kind of handbook that an ARPANET host site user would have on hand, probably sitting on their desk as they accessed their terminal to connect to the network. Since this is from MIT Project MAC, this is their handbook, and it shows us what typical sessions of a user of their Dynamic Modeling Computer Graphics PDP-10 would look like.
The document is broken up into different sections illustrating typical interactions on each of 22 different ARPANET hosts. Each section lists the quirks of the particular system, like whether to engage in full or half duplex, what characters it considers valid, and whether it is line-at-a-time versus character-at-a-time.
I really recommend at least skimming the entire original scan to get a sense of the scope of what could be done on the network in 1971, but I'll include some of the more exciting highlights here.
When a user logs in to the NIC there is normal sequence where you enter your site name as a login followed by the ARPA password as described in RFC-223. Once you're logged in you can enter a SYSTAT command to get a list of other people using the NIC system. With this information you can “link” your console to another user's console, and then type a message prepended with a semicolon, like so:
;hello are you there?
Followed by a carriage return, this will display on the console of the person you've “linked” to!
This chat service is actually provided by TENEX, the operating system that BBN wrote for the PDP-10, so other systems that use TENEX also have this chat functionality.
One bit of functionality that is not native to TENEX but rather custom to the NIC is their “NIC Journal” system, which is kind of a bulletin board or forum for posting messages for people to read!
You can type the command NLS to enter the NIC text editing system, TNLS. This opens up a new prompt for the TNLS program, at which point you can type the following to get access to the NIC Journal:
*execute journal
submit message
This is a test message.<EOT>
By typing <EOT> (“end of text”, I believe) the system knows that you've done typing your message content. Then it prompts you for a title (subject line) and id numbers of people known to the system. Then it posts your message.
Many of the records of this forum, known also as the SRI ARC Journal, are available on the Computer History Museum website as scans. If you'd like a taste of what was being posted to this forum, there's plenty at that link, though for a quick look you can see this PDF of forum posts from June and July 1971, just a few months before this booklet was published as an RFC. Yes there are big computer science papers posted in the forum but also more pedestrian stuff like IT requests for file access. See this one from page 111 of the linked PDF:
Ken..I guess I must have mis-understood what was to happen with respect to the group stuff. I am no longer in NLS' group (or whichever way it is supposed to be), which is innconvenient. [sic] Could things be fixed so I can write NLS' files again???
Thanks...Bill
“Bill” in this message is Bill Duvall, who received the first message on the ARPANET in 1969, writing to Kenneth E. Victor.
Utah: a paragon of security
The PDP-10 at the University of Utah features the password:
THISISANINTENTIONALLYLONGPASSWORD
This is the only known information about their system, as MIT has been unable to log in.
BBN: games of note
When connected to TENEX on the PDP-10 at BBN you have access to some games and toys. LIFE lets you play “game of life”, which I am assuming is Conway's Game of Life, invented just the year prior.
You can also type DOCTOR to speak to a pretend psychiatrist (sardonically noted in the booklet as “psychiatrist service--self-explanatory”)! You can read the full source code for a version of this program if you want to get a sense of what a chat with the doctor is like. I'll note that this program I've linked is probably a version that is far more developed than the 1971 edition but you get the idea!
I am glad that games are highlighted on the BBN PDP-10 because a few years after this, BBN's Will Crowther would write ADVENTURE for this very computer system, arguably the first interactive fiction computer game ever written.
Multics: customer service
If you're logged into MIT's Multics system, you can prefix a message with an apostrophe and it will go directly to a live “network consultant”! Their example of the kind of message you might want to send to start talking to the consultant is:
'Please help me on-line
There's also a local mail system between users on the system, editors, and all sorts of other Multics goodies.
Harvard: hello world
The Harvard section includes a simple FORTRAN “hello world” type program. In the following listing, . is the prompt for the operating system and * is the prompt for TECO, a text editor. The $ is apparently something that prints out if you type the <ALT> key. There are also carriage returns at the end of each line that I've omitted since they're obvious to a 2019 reader.
.R TECO
*| <TAB> TYPE 100
100 <TAB> FORMAT('HELLO THERE.')
<TAB> END
<ESC>
*EWDSK:TEST.FOR$$$$
*PWEF$$$$
*<Ctrl+C>
.EXECUTE TEST.FOR
HELLO THERE
(A user could take this documentation and replace the one-line command to print “HELLO THERE” with any complex FORTRAN program they want.)
Lincoln Lab's computer comes with the suggestion that people directly message Joel Winett with the message “HELP” if they panic!
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About me
I'm Darius Kazemi. I'm an independent technologist and artist. I do a lot of work on the decentralized web with ActivityPub, including a Node.js reference implementation, an RSS-to-ActivityPub converter, and a fork of Mastodon, called Hometown. You can support my work via my Patreon.
