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From: baba@garth.UUCP
Newsgroups: net.micro.atari16
Subject: Re: IBM 327x emulators
Message-ID: <345@garth.UUCP>
Date: Fri, 25-Jul-86 04:37:24 EDT
Article-I.D.: garth.345
Posted: Fri Jul 25 04:37:24 1986
Date-Received: Sat, 26-Jul-86 22:06:04 EDT
References: <261@vaxb.calgary.UUCP> <9@eneevax.UUCP> <242@cci632.UUCP>
Reply-To: baba@garth.UUCP (Baba ROM DOS)
Organization: The Institute of Impure Science
Lines: 40

In article <242@cci632.UUCP> rb@ccird1.UUCP (Rex Ballard) writes:
>>>    A friend has asked me to locate an emulator for an IBM 327x
>>>terminal that will run on his (1040) ST. Can anyone provide a pointer
>>>to such a beast -- I'm sure they exist, but I've never seen one.
>>>
>>I'm not so sure that such a beast exists.  The 3270 series terminals
>>are best described as workstations, not terminals in the ordinary sense.
>>Like CDC `terminals', only more picky.  3270's don't talk serial at all;
>>they have a ridiculous protocol that involves transferring entire screen
>>pages, and buffered input areas.
>>-dave
>
>This little "oops" just had to get some sort of reply.  There are 3270
>emulator packages available for the IBM-PC, two or three of which are
>written in "C" and possibly even port-able to the ST.  In addition to
>the software, a very high speed serial interface, probably through the
>DMA port will also be needed.  Specifically, the serial chip should
>support SDLC and/or HDLC protocol.

"It's a desert topping!"

	"It's a floor wax!"

Stop!  You're both right!  327x is the designation of a family of
IBM display products.  They include very dumb terminals that are the
display stations Dave refers to, as well as the relatively intelligent
control boxes, shared between multiple display stations, that Rex speaks 
of.  The interface between the tubes and the controller is a 2 Mbit/sec
(if I recall correctly) synchronous serial line with a proprietary
encoding scheme.  The interface between the controllers and their 
hosts can be a serial interface running SNA/SDLC or BSC, or a direct
channel connection.  I assume they will put them on their token ring
as well, sooner or later.

Emulating a 327x display station with an Atari or any other personal
computer currently on the market is out of the question without a
*significant* hardware assist.  Emulating a "remote" control station
would just take a lot of rather tricky software work.

					Baba