Ethan Dicks wrote:
On Thu, Jun 18, 2020 at 2:42 PM Peter Coghlan via
cctalk
<cctalk at classiccmp.org> wrote:
Thanks for your reply Paul. My eventual goal is
to be able to use the
synchronous serial interface on a MicroVAX to connect to IBM machines that
only support bisync lines.
I'm curious which software package you are using. In the 80s and 90s,
I worked for Software Results Corp, and we sold hundreds (small
thousands?) of Unibus, Qbus, and VAXBI interfaces and software suites
under the name COMBOARD for Bisync and SNA comms from DEC-to-IBM
(RSTS, RSX-11, VMS, and UNIX). In my experience, people paid us
$10K-$25K per line because they had problems with whatever other
solution they were looking at that cost less. I don't know any
specific details on where the gaps were, but just that people did
experience bugs or missing features that made them come to us. I'd
like to hear about what you are encountering once you get to the point
of passing bytes.
I am using a very old package called HUJI-NJE which implements NJE links
on VAX/VMS and UNIX. This was later developed into "funetnje" which added
some enhancements but broke the VMS functionality. I backported some
of the funetnje enhancements into HUJI-NJE in order to use them on VMS.
NJE over TCP/IP is implemented on both platforms but on VAX/VMS, there
is also supposed to be support for using synchronous serial interfaces in
the form of a DMF32, DMB32 or DSV32 (is that like a DSV11 I wonder?).
If this all works out, it may be possible to use it to get NJE links into
IBM mainframe hardware that only has support for bisync lines. It might
also have applications in talking to 3270 terminals connected via bisync
lines.
HUJI-NJE is not great for debugging the hardware with so I am also using
a pair of of example programs I found in AA?PHEPB?TE DECnet/OSI for VMS
VAX WANDD Programming.
However, I don't have access to any such IBM
kit
at the moment so I have to make do with trying to get the MicroVAX to talk
to another instance of itself for now.
For bisync (3780/HASP) that should be just fine. There's a simple
difference in the protocol so that each end can tell who is the
master, and AFAIK, any implementation you encounter should be able to
be set in the appropriate mode, but you _do_ have to tell each end
what their role is or they will chatter endlessly if they both think
they are the master.
NJE is supposed to be able to use hardware features of devices such as
the 2703 to be able to decide which end gets to be primary and which
end gets to be secondary. Sounds like it will be fun to implement...
I think endless chatter whether idle or not seems to be a feature of
bisync.
Apologies if you already know this. It's been a long time and I'm not
sure who remembers what details about obscure comms from 30-40 years
ago. I myself haven't even set up a bisync connection in 25 years. I
used to do this stuff every day, then by the mid-90s, it entirely
evaporated.
I am fairly well up on NJE but only over TCP/IP until now. All this
synchronous serial stuff is completely new to me so I am grateful for
any and all information I can get about it.
Regards,
Peter.
-ethan