Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!cs.utexas.edu!uunet!unisoft!bdt!david
From: david@bdt.UUCP (David Beckemeyer)
Newsgroups: comp.sys.atari.st
Subject: Re: Rebuttal time
Message-ID: <128@bdt.UUCP>
Date: 1 Sep 89 19:48:38 GMT
References: <8908252144.AA27005@ucbvax.Berkeley.EDU> <123950@sun.Eng.Sun.COM> <1081@philmds.UUCP>
Reply-To: david@bdt.UUCP (David Beckemeyer)
Organization: Beckemeyer Development Tools, Oakland, CA
Lines: 109

In article <1081@philmds.UUCP> leo@philmds.UUCP (Leo de Wit) writes:
>In article <123950@sun.Eng.Sun.COM> cmcmanis@sun.UUCP (Chuck McManis) writes:
>|and the ST/Mac/PC user who is saying :
>|	"You know, if only I had a multitasking OS, this is what 
>|	 I could accomplish."
>
>Compiles in the background, a file being printed, while reading netnews ...
>Wow!
>
>    Leo.

OK, I do all the above on a Mega ST-4 with MT C-Shell, Mark Williams C,
the MT C-Shell print spooler, and the Bootstrap News software with 
MT C-Shell UUCP.   Using the visual shell (VSH), I can even do it
with GEM windows.   Admitedly, using VSH is slower and on the
rather small ST screen, it isn't as nice as a 19" monitor. But it's
handy to be able to have, for instance, a kermit login session to 
a Unix box in one window, with a local compile shell in another, and
another local (inactive) shell in case I want to type another command
(e.g. to check out a local file).  It all works.  It's not a Cray, but
you can do it, today, with software and hardware that exists and that
you can really buy for an Atari ST.

A plug you say?  Well maybe - but it's also true.

Another example of real multitasking on the ST is the custom systems that
we have developed based on the RTX kernel.   Here's an internal layout
of a 4 user custom Point-of-Sale/Accounting system installed at a Art
Supply.  It has two touch screen POS 1040 ST computers, with bar code
readers, and receipt printers.  It has a Wyse-60 terminal used for
receiving merchandise into inventory and bar code ticketing.  It is
all run from a 1040 ST with a BMS drive.

Each touch screen 1040 system runs RTX with the following processes.
The connecting lines show interprocess communications.

	Application (draw graphics, interact with user)
		^		^
		|		|
		|		v
		|	   Network Protocol <-> Host Server (special ops)
		|		^
		v		|
	   Multplexer <---------+
	     Driver
		^
		| RS-232 port
	 	v
	     Multiplexer (Hardware)
	     |  |  |  |
	     |  |  |  +- Touch screen I/O
	     |  |  +---- Network (Host)
	     |  +------- Printer
	     +---------- Bar Code Reader

The main 1040 also runs RTX and has the following cooperating processes:

	POS/Accounting Application	POS/Accounting Application
	System Console			Wyse 60 Terminal	
		^				^		^
		|				|		|
		+----------+   +----------------+		|
			   |   |				|
			   v   v				|
			  DataBase <---> (Hard Disk Databases)	|
			   Server				|
			   ^   ^				|
			   |   |				|
	Touch Screen <-----+   +------>	Touch Screen		|
 	    Server			    Server		|
		^				^		|
		|				|		|
		v				v		|
	Network Protocol		Network Protocol	|
		^				^		|
		|				|		|
		|				|		|
	   Multplexer --------------------------+		|
	     Driver   ------------------------------------------+
		^
		| RS-232 port
	 	v
	     Multiplexer (Hardware)
	     |  |  |  |
	     |  |  |  +- Network I/O to Touch screen #1
	     |  |  +---- Network I/O to Touch screen #2
	     |  +------- Bar Code Printer
	     +---------- Wyse 60 terminal

 
Actually there are even more tasks than show in the pictures because
some functions of the main applications are actully spawned off into
a sub-task, as needed.  The database server uses the client/server model
using RTX message queues to communicate.  The touch screen systems
communicate with the Host 1040 using RS-232 with a error correcting
packet protocol.  The network protocol runs independently and asychronously
from he rest of the system (i.e. a packet could come in at any time).

The above described system has been running for almost three years.  I
used it as an example because it is uses 100% Atari ST computers (3 1040s)
and all the CPUs are running RTX in real-time, commuicating 24 hrs. a
day 365 days a year.

So now somebody tell me there isn't any usable multitasking for the ST.
-- 
David Beckemeyer (david@bdt.UUCP)	| "I'll forgive you Dad...  If you have
Beckemeyer Development Tools		| a breath mint."
478 Santa Clara Ave. Oakland, CA 94610	|    Bart - "The Simpsons"
UUCP: {uunet,ucbvax}!unisoft!bdt!david	|