[ih] NCP and TCP implementations

[the keyboard of geoff goodfellow]

in addition to TIP/TAC, ANTS, and ELF there was also a number of different
implementations of/a TSP: *Terminal Support Processor *such as the one at
Lincoln Labs (LL-TSP) detailed in
https://apps.dtic.mil/dtic/tr/fulltext/u2/726534.pdf

there was also a PDP-11 TSP version -- not related to the LL-TSP version --
(that might have come from ISI?) that yours truly brought up on on the Earl
Craighill and Tom Magill (SRI-NSC11 host) when it was sitting idle (i.e.
not being used for/with the Voice over IP of ARPA's Network Speech
Compression program) which had a single dial-up modem on it and provided
for "alternative access" when all of the direct SRI-AI dial-up lines
scanner PDP-10 Tenex system lines were busy/in use. :D

geoff


On Tue, Mar 10, 2020 at 9:48 AM Alex McKenzie via Internet-history <
internet-history at elists.isoc.org> wrote:

>  The key driver was that the TIP be managed as part of the network, rather
> than as part of a user organization.  That meant that BBN followed the same
> rules for the TIP that they did for the IMP, which included "no rotating
> storage", which in those days was quite unreliable in a MTBF sense.  And we
> wanted it to be in the same box as the IMP, sharing a processor, so it had
> to exist in 16K of 16-bit words.  Other approaches, like ANTS and ELF, ran
> in separate boxes and were run by user organizations, so more buffers and
> more code for specialized I/O devices were possible.  ARPA supported, one
> way or another, all of the TIP, ANTS, and ELF.
> Cheers,Alex McKenzie (BBN 1967-96)
>
>     On Tuesday, March 10, 2020, 2:20:35 PM EDT, Leo Vegoda via
> Internet-history <internet-history at elists.isoc.org> wrote:
>
>  On Tue, Mar 10, 2020 at 11:07 AM Steve Crocker via Internet-history
> <internet-history at elists.isoc.org> wrote:
> >
> > To create the TIP, a second bank of memory was added to the 316 and some
> > interrupts and modes were added to enable switching back and forth
> between
> > banks.  It was a bit of a kludge with some unexpected interactions.  The
> > BBN crew finally sorted out the details and wrote a delightful titled
> "It's
> > Amazing That it Works at all."
>
> Am I right in inferring that the key driver behind the design decision
> was cost rather than elegance?
>
> Thanks,
>
> Leo
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>

-- 
Geoff.Goodfellow at iconia.com
living as The Truth is True
http://geoff.livejournal.com