[ih] Significant milestones in the history of TCP/IP

[dave.walden.family at gmail.com]

As Bob Armstrong knows, the IMP code (from 1973 or there abouts) that Bob simulated was highly tuned for the actual line speeds of the net.  Maybe the code knew about something less than 56KBS (I'd have to study the listing).  Also the IMP knew of a maximum of 5 inter-IMP modem interfaces, and I don't think it ever used more than 4 and I think option for the 5th doesn't work (at least in the simulated version, and likely in the real code).  Thus simulating lots of low speed lines might require modifying the IMP assembly code.  

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On Sep 17, 2015, at 4:14 PM, Jacob Goense <dugo at xs4all.nl> wrote:

> On 2015-09-17 19:11, jnc at mercury.lcs.mit.edu wrote:
>> I suspect the only way to say with any certainty how well a network 
>> built out
>> of lots of slow lines, as opposed to a few fast ones, would have worked 
>> is a
>> comprehensive simulation. Which is not likely to happen, of course! ;-)
> 
> Well, there is an ARPAnet IMP in simh now. According to Bob Armstrong..
> 
> "The hooks are in there to allow simh to support the IMP side of the
> 1822 host interface, and the next step would be to recover the OS for
> an ARPAnet era host and then extend the corresponding simulator to talk
> to the IMP simulation."
> 
> 
> 
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