by Darius Kazemi, Jan 12 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.


RFC-12 is by Michael Wingfield, and is his only RFC, dated Aug 26th, 1969. According to the Kleinrock History Center at UCLA,

Michael Wingfield designed the interface linking the SDS Sigma 7 computer at UCLA with an Interface Message Processor (IMP) in 1969 and implemented TCP/IP for Unix in 1979.

The technical content

The document is a handful of flowcharts extracted from BBN Report No. 1822. Report 1822 was BBN's documentation on how to connect a HOST to an IMP.


Since hooking up a HOST to an IMP was literally Wingfield's job, it makes sense that he'd extract some important summary diagrams and distribute them to the RFC recipients. They probably came in handy and made sense to have as a separate reference document while you were sitting down trying to figure out the physical hookups and data interchange of these machines.

Further reading

The only available scans of BBN Report No. 1822 I can find online are from its 1976 revision, which is 7 years after this document was written and according to its own foreword varies significantly from the original. I'm going to a bunch of archives this year and I'll try to dig up a 1969 edition.

The Kleinrock History Center hosts a collection of Wingfield's documents including many from the project to hook up UCLA's Sigma 7 HOST to an IMP. A lot of these documents are electrical engineering related rather than computer science, which I think is really neat. For example, these pages contain things like impedance calculations for cables and this page has a diagram of the actual wire-by-wire connections required:

a cable crimping diagram

How to follow this blog

You can subscribe to this blog's RSS feed or if you're on a federated ActivityPub social network like Mastodon or Pleroma you can search for the user “@365-rfcs@write.as” and follow it there.

About me

I'm Darius Kazemi. I'm a Mozilla Fellow and I do a lot of work on the decentralized web with both ActivityPub and the Dat Project.