I like a challenge although it wasn't really much of it. A simple arpa imp in yahoo spilled the beans :-) "The Interface Message Processor (IMP) was the packet switching node used to interconnect participant networks to the ARPANET from the late 1960s to 1989. It was the first generation of gateways, which are known today as routers.[1][2][3] An IMP was a ruggedized Honeywell DDP-516 minicomputer with special-purpose interfaces and software.[4] In later years the IMPs were made from the non-ruggedized Honeywell 316 which could handle two-thirds of the communication traffic at approximately one-half the cost.[5] An IMP requires the connection to a host computer via a special bit-serial interface, defined in BBN Report 1822. The IMP software and the ARPA network communications protocol running on the IMPs was discussed in RFC 1, the first of a series of standardization documents published by the Internet Engineering Task Force (IETF)." https://en.wikipedia.org/wiki/Interface_Message_Processor Cheers, uncle rubl From: Dave Horsfall <dave(a)horsfall.org> To: Computer Old Farts Followers <coff(a)tuhs.org> Cc: Bcc: Date: Wed, 9 Dec 2020 13:41:11 +1100 (EST) Subject: Re: [COFF] ARPAnet now 4 nodes On Sat, 5 Dec 2020, Noel Chiappa wrote: Yeah; see the first map here: http://www.chiappa.net/~jnc/tech/arpageo.html Yep; I know that first map well :-) For the newbies here, the ARPAnet was the predecessor of the Internet (no, it didn't spring from the brow of Zeus, nor Billy Gates), and what we now call "routers" were then IMPs (look it up). Missing maps gratefully received! Indeed; history needs to be kept alive, lest it die. -- Dave