Path: utzoo!attcan!uunet!ncrlnk!usglnk!uncrcmd!news1
From: news1@uncrcmd.Dayton.NCR.COM (Jeff Van Voorhis)
Newsgroups: comp.binaries.ibm.pc.d
Subject: Re: Multiuser 286 questions?
Keywords: multiuser, 286, 386, terminal, multiport, RS-232, OS, database
Message-ID: <322@uncrcmd.Dayton.NCR.COM>
Date: 6 Jul 90 13:22:26 GMT
References: <1990Jul5.203820.26995@eng.umd.edu>
Reply-To: news1@uncrcmd.UUCP (Jeff Van Voorhis)
Organization: NCR Cooperative Marketing Division
Lines: 58

In article <1990Jul5.203820.26995@eng.umd.edu> naiming@eng.umd.edu (Naiming Shen) writes:
>
>I want to design an application system, on which using a 286 or 386 machine,
>and use several terminals and printers connecting to the machine. Anyone
>from a terminal can access the database on computer at the same time and
>can print a record to his/her own printer. Maybe 6-7 terminals and printers.
>Now my question is:
>
>1. what kind of machine should I use, 286 or 386?
I would suggest a 386SX machine if you are considering a 286. The price is
generally very close to a 286 with much better performance. We have run 10
users on a 386SX system without problem. (Xenix OS)
>
>2. what kind of operation system to use, DOS, P-DOS, Xenix, or some multi-
>   user shell like MultiBase?
Unix, Xenix: If you are considering terminals (Dumb Ascii CRTs). You may also
consider Novell LAN if you experience is in MS-DOS <--(Yuck!). The big factors
here are cost, your experience, and end user interface.
>
>3. what kind of multiport to use, Digi-Board or other RS-232 board?
>
I have no specific suggestion here.
>
>4. what kind of database to use, for multiuser do I have to load database
>   program several times or just load one copy? 
That depends on the complexity of your application. In the Unix (Xenix)
world one loads a single copy on the machine and pays a fee linked to the
size of your equipment (users, class of machine, etc..) Under MS-DOS you
would use a network version of the Database Software. If you are new to the
Relational Database World you might consider looking at comp.database for a
while.
>   how hard to program for  multiuser database? 
Not very hard. IF you use a version designed for multi user!!! Do not try 
to trick a single user database into working like a multi user version.
>
>   Are there good books for programming multiuser
>   database?
I found several. A good textbook on the subject is by C.J. Date:
"An Introduction To Database Systems". It is really not difficult IF you
use a relation database system - they do all the hard work for you.
>
>5. Can terminal and printer together share one cable connecting to a
>   RS-232 port on the computer.
Yes, most terminals allow a mode called pass through mode. This redirects
all terminal output to its Auxillary port. The Unix spooler can be set up
to handle this. I would not suggest this if you have the serial ports to 
do dedicate to a printer(s).
>
One last thing. Please investigate other sources for this application. You
might just find that someone has already written it for you.

-----------------------------------------------------------------------------
As normal these opinions are my own ....
-- 
*   Jeff Van Voorhis  NCR Corporation CMD Division    *
*   Dayton, Ohio 45479   (513) 445-5267               *
*   jeff.vanvoorhis@Dayton.NCR.COM 		      * 
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