Replies inline:

On Tue, Oct 11, 2022 at 1:31 AM Lars Brinkhoff <lars@nocrew.org> wrote:

TUHS Disclaimer: I will claim this is primarily about getting Unix onto
the Arpanet, but it does also contain trace amounts of off-topic
information.  Reader discretion is adviced.

Michael Casadevall wrote:
> I do need to do a readthrough for the VDH driver, which says its for
> "very distant hosts".  I think that might be for the radio links

The hardware interfaces between a host and an IMP came in three flavors:
local host, distant host, and very distant host.  The first two are more
or less directly connected and I forget what the difference is.  But a
very distant host is basically connected over a phone line with a modem
at each end, so it's a different beast.  The VHD driver would be for
this, whilst IMP11A and ACC are local or distant.

That makes sense; most of the time, the documentation that survives implies

the IMP is always local; knowing this is important. From what I got the impression

From the docs, very early ARPA, you had systems directly on the network, but most

users had to dial into a specific terminal machine, which, based on the comments

on the RFCs, was less than ideal, although I haven't quite figured out how things like

netmail worked.

VHD I guess was more to get more hosts online?

> Hawaii

Side note: apparently tapes from the unique Hawaii BCC 500 have been
saved.  So maybe that's one more possible re-Arpanet host.

Oh very nice. Depending on how that works, it might be possible to make a radio link

over ham. I haven't seen anything about these links aside from them being marked

the logicial maps.

 

> Yup, that's what I figured. I've been trying to evaluate how much
> survives

Here's my take:
https://gunkies.org/wiki/Network_Control_Program_(ARPANET)#Implementations

So there are like four PDP-10 systems and two PDP-11.  The ELF system
will be a major challenge, RATS haven't been scanned off the printer
listing, and the BCC 500... oh boy, let's not go there now.

 Well, there's multiple UNIX v6 stacks. There's the NOSC one which I tried to build,

and I think is the oldest. The BBN  with TCP stack is a bit mislabeled: it still appears

to support NCP, but none of the client apps are there, but its directly built off the NOSC

stack. it's probably a fork from earlier in development. 79-80 timespawn would have been

*very* early in TCP's life

> I don't know if a runnable build of TENEX has been archived,

I think so.  I "almost" got one running but there was some problem... 

 

> or if ARPA stuff for TOPS-10/20 survived.

TOPS-20AN seems to be there.  TOPS-10, nothing so far.

> I also want to look into System/360 and 370, but I get the sense none
> of the mainframe stuff survived.

I asked around; found nothing.  CDC, same.

Oof, although par the corse for mainframe preservation :(

 

> The other problem is of the surviving stacks, they all seem to be for
> the later 96-bit leader, I'm not certain if any of the IMP software
> that has been archived is new enough to work with that.

Nothing for the 316/516 IMP, as far as I know.  Pluribus IMP emulator,
anyone?

I do actually wonder how hard that would be. The NCP kernel code seems to suggest

it would be straightforward all things considered. It honestly reminds me  Hayes modem

commands of all things ...

Michael