Michael Casadevall wrote:
> part of impio.c is cut off. However, this isn’t quite as bad as it
> sounds. For example, by kitbashing both the original v6 source code,
> and the later BBN TCP code, I was able to create a sys4.c that builds
> and links which should be close to the original. Furthermore, it is
> possible to use the “vdh” target instead of the imp target to at least
> try and get the code building.
Too bad about impio.c! Maybe something can be extracted from the
unix.greg binary? I see there's also the ACC interface, another
alternative to IMP11A.
Well, there is an impio.c in the BBN TCP code which has #define NCPs, which
I used to rebuild the original impio.c; although this is very much a devil in the
details situation.
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 to Hawaii and the UK? I vaguely remember coming
across that term in my reading, but I'm drawing a blank ATM.
I did try to run the unix binaries in green and green47, but they seem to be configured
for a RL0x drive of some sort; the driver is in the NOSC source, so it might be possible
to get running, but without the host binaries, you'r enot going to get far.
> My guess is it's either deadlocked waiting for the IMP, or there’s
> something wrong with the build.
Since you don't have anything backing the hardware registers for the IMP
interface, it seems likely something will be upset.
Well, I'm not sure if its trying to initialize the IMP on startup; there's a userspace daemon,
ncpd which talks to the /dev nodes to do stuff; with network nodes showing up as /dev/net/*host.
I did determine I at least seem to make it to sched() with my home cooked kernel, but I can't even
start in single user mode.
Honestly, it reminds me of Plan 9 more than anything.
> Furthermore, I do know that I can run some of the ARPA level utilities
> in MIT ITS on CHAOSNET, which will be an upcoming project, although
> that is going to be a dive in and of itself.
It's complicated. Many of the utilities have parallels between the two,
and some work on both. And there's a server to provide a gateway from
Chaosnet to Arpanet. Give me a ping when you're looking into ITS.
Will do. ITS feels like an extremely deep (if interesting) rabbithole :)
> I know IMPs have been emulated, and even have successfully routed
> packets, so I’m also trying to figure out how much would still be
> necessary to actually recreate a minimal ARPA network?
Reviving the host software, like you are are doing, is one vital part of
it. Another it adding emulators for various IMP interfaces. I.e. you
will not get anywhere without adding one of IMP11A, ACC, or VDH to SIMH.
Yup, that's what I figured. I've been trying to evaluate how much survives here, but
my general feeling is one of the UNIX stacks might be recoverable, plus the ARPA
stuff in ITS. I don't know if a runnable build of TENEX has been archived, or if ARPA
stuff for TOPS-10/20 survived.
I also want to look into System/360 and 370, but I get the sense none of the mainframe stuff survived.
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.
That said, that isn't an insurmountable problem.
~ NCommander