What I understand now is that the 90L+ is
"single-ended" device that
expects some server-thingy / software on the other end of the Thinwire...? 
I think that sums it up pretty nicely.  The 90L+ is nice becuase it's able to function
as soon as you power it up (some DECservers such as the 200 require the program to be
loaded from a remote host before they'll work).  It sucks becuase it can't do
reverse LAT (aka act as a console server, which seems to be what you want), or Telnet.
BTW, you might look into console server software.  If you can come up with a Unix box with
multiple serial ports, that might actually be your best bet (I've got a 16-port
adapter for one of my Sparcs for just this sort of use).
                Zane
--
--
| Zane H. Healy                    | UNIX Systems Administrator |
| healyzh(a)aracnet.com (primary)    | OpenVMS Enthusiast         |
|                                  | Classic Computer Collector |
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|     Empire of the Petal Throne and Traveller Role Playing,    |
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http://www.aracnet.com/~healyzh/               |