[ih] when did APRANET -TIPs become known as -TACs

[Noel Chiappa]

    > From: Jorge Amodio

    > TIP (Terminal Interface Processor) ~= TAC (Terminal Access Controller)

The biggest difference between the two was that the TIP used the older
Network Control Protocol protocol family, whereas the TAC was also able to
use the newer TCP/IP family. (I see from "Getting Started Computing at the AI
Lab":

  https://dspace.mit.edu/bitstream/handle/1721.1/41180/AI_WP_235.pdf

that a TAC user could switch back and forth - pg. 17 of the PDF.)

The TIP also included IMP functionality, and TIPs could be ARPANET nodes; the
'MIT-TIP' machine used to be one of the two IMPs at MIT: IMP #44, to be exact.
Not so for TACs.

Does anyone remember how TACs which used to be TIPs connected to the network,
though? (I mean using what hardware?) I see that the host 'MIT-TIP' used to
be 2/44; i.e. host 2 on IMP 44. That machine would have conncted to the rest
of the ARPANET via phone lines (so through a modem port). However in its
later 'MIT-TAC' incarnation, it was 10.2.0.77; i.e. it was connected to IMP
77 - I would assume via an 1822 port? Did ex-TIP machines use one of their
one-time 1822 'IMP' ports as a 'host' 1822 port?

I should know that, because I was the MIT 'IMP liaison', and I do remember a
bunch of events with them (e.g. the move of MIT-MC, which involved converting
an LH port on a C/30 IMP to a DH), but I have no memory of the switch to the
C/30 IMPs.

Also, were there any TACs which were not one-time TIPs? If so, what was the
hardware base? Maybe a C/30 with a multiple serial line controller?

	Noel