[ih] Intel 4004 vs the IMP

[Alex McKenzie]

 The IMP could have up to 7 connected devices total.  Up to 5 could be phone lines.  Up to 4 could be hosts. The terminal handling portion of the TIP counted as a host.  [When the Very Distant Host Interface was introduced in the mid-1970's it counted as 2 devices.]  There was one ARPAnet circuit that ran at 230kbps (within NASA AMES) and two that ran at 19.2kbps (US to Norway, and Norway to England).  As far as I can recall, all the rest ran at 50kbps.
Cheers,Alex

    On Monday, November 15, 2021, 10:01:05 PM EST, Jorge Amodio via Internet-history <internet-history at elists.isoc.org> wrote:  
 
 Weren't the BBN modems capable of handling up to 6 "phone lines" at
50,000bps. So basically analog dedicated phone lines.

I'm sure the early lines were not DDS 56K

Regards
Jorge


On Mon, Nov 15, 2021 at 8:35 PM Steve Crocker via Internet-history <
internet-history at elists.isoc.org> wrote:

> Arpanet lines were 50 kbs, not 56 kbs.
>
> Sent from my iPhone
>
> > On Nov 15, 2021, at 9:11 PM, Timothy J. Salo via Internet-history <
> internet-history at elists.isoc.org> wrote:
> >
> > I think we all agree that the IMP was a pretty limited machine.  From
> > the backup slides of a presentation of mine:
> >
> > Early ARPANET router, Interface Message Processor (IMP), (1969):
> > o 16-bit words, 12-16 K-word memory
> > o 100-μsec clock (10 KHz)
> > o Early ARPANET links: 56 kbps
> > o 0.18 clock cycles per bit
> >
> > I have argued that this, 12-16 K words of memory, is why we had the
> > end-to-end argument (which morphed into a principal and then into a
> > canon).
> >
> > (The rest of the presentation pretty much ignores the end-to-end
> > argument.)
> >
> > Also from this presentation:
> >
> > Early NSFNET router: DEC LSI-11/73 (1983) with Fuzzball router
> > o 512 KB memory
> > o (15.2 MHz)
> > o 271 clock cycles/bit
> >
> > -tjs
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