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Re: Removing ARCNET stuffs



On 2015-05-29 16:35, Paul_Koning%Dell.com@localhost wrote:

On May 29, 2015, at 6:22 AM, Johnny Billquist <bqt%Update.UU.SE@localhost> wrote:

On 2015-05-29 08:18, Matt Thomas wrote:
...

I have a Phase IV+ (so I didn’t have to much with the physical address) implementation but never got around to writing the apps.  socket interface is identical to DECnet-ULTRIX.  DAP is a beast as is CTERM.  I could run IP protocols over, but then I have IP for that. :)

If you say that you didn't fiddle with physical addresses, then you have been playing Phase V, as Phase IV requires that you manipulate the physical address. And that is also true of IV+.

Maybe Matt meant IV-prime?  That’s an obscure variant of Phase IV invented to allow DECnet to run on 802.5 networks.  I recently found a spec for it.  It isn’t all that hard; the changes are just in the routing layer.  And yes, it allows you to keep your physical address, so long as all the neighbors you need to talk to also run IV-prime.

I remember seeing some note about an update to Phase IV to allow communication over 802.5 that would allow the interface to not have DECnet-specific addresses, but I haven't actually seen any implementation. But you could be right in that this is what Matt meant.

Of course, if you have a LAN driver and interface that supports multiple individual addresses, you can use the HIORD style address for DECnet while keeping the conventional physical address for other protocols.  Most hardware supports this, actually, though it’s not clear how many drivers do.

DAP would be really nice, but it's complex. But I like the capabilities.

I wouldn’t have thought of DAP as all that complex; after all it fits in PDP11 systems.  You can probably subset it pretty nicely if you don’t need all the features.  Just file transfer, as opposed to transparent file I/O, is likely to simplify things substantially.  The DECnet/Linux implementation of DAP does this, I believe, and it does a reasonably good job.  I think I even got it to talk successfully to a RSTS/E system at one time.

I've never managed to get DAP under Linux to talk with an RSX node...
And I don't think you can subset it much. Depending on the remote machine, different parts will be exercised. But I guess things like indexing file access could be left out. But it's still rather more complex than anything I've seen under Unix. But possibly various remote db protocols would be similar.

File transfer and file access in DAP is the same thing, I believe. Or maybe you mean this in some way I'm missing.

	Johnny


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