[ih] Protocol numbers (was IP version 7)

[Alex McKenzie]

 Noel,
The first IMP interface was the one you know about - the bit serial interface.  There was NEVER a parallel interface.  I think perhaps the author of the "parallel interface" mis-information was confused by the fact that there were several parallel SIGNALS which made up the interface - for example some of the different signals were:  "ready for next bit", "here's your bit", "bit received", ...
Alex

    On Friday, December 25, 2020, 6:57:26 AM EST, Noel Chiappa via Internet-history <internet-history at elists.isoc.org> wrote:  
 
     > From: Brian E Carpenter

    > ** "Early Experiences with the ARPANET and INTERNET in the UK", 1998

Very interesting, thanks for the pointer.

It contains one thing that I'm curious about: "the Interface Message Processor
(IMP). This were initially attached locally to Host computers by a parallel
interface." (bottom of pg. 2) I'm unaware of this stage; I thought they always
used the 1822 bit-serial interface? I'd look at my copy of the BBN proposal
(in response to the DARPA RFP), which probably talks about whether the plans
were always for that interface, but alas my son and his wife are asleep in the
room it's stored in, so I can't. I suppose it's possible a first IMP or so
were prototypes, and initially used a parallel interface, later replaced by
the 1822 interface, but I don't recall hearing about that. Can anyone expand?

    Noel

PS: That site, ban.ai/multics/, is completely mind-blowing. Check it out.

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