[HECnet] DDCMP over serial lines in RSTS V10.1

[Paul Koning]

> On Mar 13, 2020, at 4:17 AM, Tim Sneddon <tim at sneddon.id.au> wrote:
> 
> On Thu, Mar 12, 2020 at 9:45 PM Paul Koning <paulkoning at comcast.net> wrote:
> >
> > I thought that I had sent a message to the list a few months ago showing the procedure to use the software DDCMP driver in RSTS V10.1.  That's a standard feature, but undocumented and probably unsupported.  It works well and interoperates with PyDECnet and with the DDCMP implementation in SIMH.  Presumably it will talk to the software DDCMP in RSX, though I have not tried that.
> >
> > Attached are the instructions and the program mentioned.
> 
> From the first line of async-rsts.txt:
> 
> =======
> Software DDCMP in RSTS/E V10
> 
> NODVR, a software DDCMP driver was written for V9.6 as part of PRO 
> support (an unreleased and unsanctioned effort).
> =======
> 
> Does this mean that there is support for running RSTS on a PRO desktop?  Time to rummage through the source... 

Yes and no.  I implemented PRO support for RSTS in 9.6, and ported it to 10.1.  The INIT part of that was merged with the official sources and exists in V10.1 (I forgot if it is also in V9.6).  So you can boot into INIT on a PRO.  But the monitor part was not merged.  I would like at some point to make that available.  One possibility, which I packaged up some years ago, is a set of 3 floppies which replace the first two of the 10-disk MicroRSTS kit (called V1.0, which is a V9.6 repackaging).  The DECnet part needs some more cleanup, though.  And I don't yet have CNA (PRO Ethernet) support).

I wrote NODVR, the software DDCMP driver, as part of that V9.6 effort.  The RSTS team decided to merge that as well, but they changed how it is controlled in V10 -- for the better.  And that is entirely independent of the PRO work, it operates with any serial line.  Well, on the PRO there is an additional item: it can run the comm port in synchronous mode, which lets you talk to a DMC or the like if you have a synchronous modem or sync modem eliminator.  

	paul