[Simh] terminal multiplexers

[Johnny Billquist]

On 2015-11-12 16:08, Armistead, Jason          BIS wrote:
> Patrick Finnegan <pat at computer-refuge.org> wrote:
>
>> DEC's DECserver, Xyplex Maxserver, Annex terminal servers, and Xylogics (for the ones I have touched and remember) all converted telnet into
>> real RS/EIA-232 lines. (telnet client -> host serial, or serial terminal -> host telnet server)
>
> The early DECservers like the DECserver 100 & 200 models only spoke LAT protocol to host systems, and required a MOP boot file download to get up and running.  The early models had a Motorola 68000 CPU inside them, and just enough firmware in EPROM to do some basic startup diagnostics and complete the MOP boot.  The later DECserver 90M (introduced circa mid 1990s) was one of the first to support Telnet in addition to LAT, and had all their firmware on board.

In addition, the DECserver 100 could not even do reverse LAT (ie, 
connect with LAT do get out on a physical serial port).
And in between the 200 and the 90M you had the DECserver 300, which with 
version 2 firmware also supports telnet. However, it also MOP boots.

> See https://en.wikipedia.org/wiki/DECserver for a bit of an overview of the various models and capabilities.
>
> I originally used DECserver 200s running LAT on our VAX/VMS systems, but I believe it was also available on PDPs (running RSX ?) and Ultrix / OSF/1 / Digital Unix, and nowadays there is even an open source LAT and MOP daemon implementation for Linux.

LAT is available on both RSX-11 and RSTS/E, as well as TOPS-20. The free 
LAT implementation for Linux have issues, though.

> The DECservers 200s were rock solid performers in our engineering offices and on the factory floor.

Agreed. 200 and 300 were/are great.

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
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