[Simh] RTS/8 and DECnet

[Paul Koning]

> On Mar 15, 2016, at 5:47 AM, Johnny Billquist <bqt at softjar.se> wrote:
> 
> ...
> I don't remember who I talk to, but it might have been Paul, but it appears DECnet-8 is pretty much Phase I, from what we figured out. Maybe DEC wrote some newer version that have not been found, since documentation and SPDs mention Phase II.

I saw an RTS/8 document that describes Phase I -- studied it some to see what Phase I protocol looks like.  The answer is: significantly different from Phase II, not interoperable, no plausible way to make it interoperate.  The key problem is that the NSP details are different, so a Phase I endpoint trying to talk to a Phase II endpoint would get lost.  Compare that to Phase II through IV where the NSP is basically the same -- Phase III adds retransmission, but the packet formats are upward compatible.

But I also remember hearing about Phase II on PDP-8 systems.  So it seems likely that Phase I was created at some time, only to be superseded by a Phase II implementation.

	paul