7 Oct
2020
7 Oct
'20
4:47 p.m.
On Wed, Oct 7, 2020 at 7:32 PM Peter Coghlan via cctalk
<cctalk at classiccmp.org> wrote:
Ethan Dicks wrote:
I completely agree. It's terribly chatty and expects turnarounds
very, very quickly. The OP didn't indicate the distance of what he
wanted to accomplish, so I've just been considering both ends are in
the same room, not in two different locations - i.e., a demo not a
real-world production-ready solution.
There are no implementations of sync serial
devices in Simh. That
would have to be written in any case. The DU11 and DUV11 are very
simple PIO serial lines with, IIRC, a COM5025 USART...
This is (more or less, not exactly) what the orginal 2703/bisync emulation
in Hercules does...
The bisync/RJE protocol is a great fit for being generated by hardware and
being sent over a dedicated line. It is a poor fit for being generated
by software and being sent over a shared TCP/IP network. There is lots
of bandwidth wasting chatter and lots of CPU is consumed in mostly achieving
nothing useful.
Totally.
Applications tend to be coded with fixed, short
timeout values.
Yes.
The link I included describes how to avoid these
difficulties for NJE
by using a very different protocol which is specifically designed for sending
NJE over TCP/IP networks. I believe a similar approach is needed to do RJE
successfully, especially if it is to end up working across the internet rather
than just across a lab under ideal conditions.
Indeed. If the goal is to have it work across the internet rather
than across the room, yes, an additional management layer is needed.
-ethan