[HECnet] DECnet Implementation and Productization of RSX-11M, 11S, 11D and IAS (was Re: Anonymous FAL (Tops-20))

[Thomas DeBellis]

I had been wondering about the RSX DECnet packaging.

Pre-CI DECSYSTEM-20's may be modeled according to a loosely coupled 
multi-processor paradigm, with the main KL being communicated with 
DTE20's, the master one having additional rights.  These were connected 
to either a front end communications processor (which handled the 
communications, unit record equipment and I believe the ANF10) and other 
networking.  These were packaged in separate cabinets as DN20's.

The DN20 subsystems were 11/34 - 11/40 class machines, which might now 
be better thought of as ancillary processors or even embedded systems, 
but sometimes were running cut down versions of full blown operating 
systems.   The front end ran a version of RSX called RSX20F and was 
somewhat stripped down, not having a login.

A DN20 was termed a DN20 if it ran the 2780/3780/HASP communications 
code that IBMSPL talked to.  Since I was Columbia Galaxy nerd and knew 
PDP-11 assember, I also maintained that code (and worked with our VM/MVS 
folks to fix a pesky bug in the multi-leaving implementation).   As I 
recall, this was embedded code and precisely RSX based (but it's been at 
least 35 years since I assembled any of that).  I think I used a 20 
based cross assembler to do it.

We did have an RSX20F pack, but I don't recall as I ever looked at 
source on that.  Or maybe it was on microfiche.

Do you know how DECnet would have been packaged for the DN20 and DN200 
(the DECnet based RJE station)?  One assumes it would have been built 
off of RSX.

I can't remember whether the DN20 would do anything past Phase III.

> ------------------------------------------------------------------------
> On 7/5/2019 7:57 PM, John Forecast wrote:
> What you see in CEXBF.MAC is all there ever was for CEX. When I joined the development team in Jan ’77, an implementation of Phase II NSP was running standalone under a “Communications Executive”. The decision was made to “port” this “Communications Executive” into each of the RSX-11 Decnet implementation (11M/11S/11D and IAS) and they would all use this NSP implementation. As a side benefit we would get all the device drivers that had been implemented as well.
>
> [...] that would be too expensive if every packet had to flow through NETACP. When a packet is queued to a process (asynchronous rather than direct call) it is queued to the NS: fork block. When NS: driver runs as a result it peeks at the request and may queue it to NETACP or process it immediately.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sonic.net/pipermail/hecnet-list/attachments/20190714/bbab7d38/attachment-0001.html>