Newsgroups: comp.robotics
Path: brunix!news.Brown.EDU!noc.near.net!howland.reston.ans.net!agate!doc.ic.ac.uk!uknet!newcastle.ac.uk!eata!ndg2
From: David.Glennie@newcastle.ac.uk (David Glennie)
Subject: Re: Multitasking software for Real-time Control Application
Expires: Wed, 15 Sep 1993 23:00:00 GMT
Nntp-Posting-Host: eata
Message-ID: <CD2yy0.L9t@newcastle.ac.uk>
Organization: University of Newcastle upon Tyne, UK NE1 7RU
References: <8SEP199319174259@vax2.concordia.ca>
Date: Thu, 9 Sep 1993 09:41:59 GMT
Lines: 67

In article <8SEP199319174259@vax2.concordia.ca> avrao@vax2.concordia.ca (VENKATESWARA RAO A.) writes:
>Dear Friends,
>
[stuff deleted]
>I am looking for a software which can help me perform multi-tasking on
>IBM PC 486.  I wish to open two DOS shells and perform two tasks
>simultaneously.  In one of the DOS shells, a TURBO graphics program being
>developed by us will be executing.  It might also have to comunicate through
>the RS-232 port. In the other shell, a transputer fileserver, used to service
>INMOS T 800 transputers (parallel processors), will be executing.  These
>parallel processors are mounted on a motherboard which is plugged onto the
>PC.  The fileserver enables the transputers to obtain access to the Screen I/O
>and Disk I/O facilities of the host PC.  The fileserver is a polling type 
>server.
>
>I would like to know if anyone on the net has experience with any multi-tasking
>software which has been used for real time control application.  Two software
>packages suggested to me are DESQview and OS/2.  I would be grateful if anyone, 
>who has performed multitasking with these softwares, can share their experience.
>
>Thanks in advance.
>
>Venkateswara Rao A.
>avrao@vax2.concordia.ca
>Centre for Industrial Control
>Dept. of Mech. Engg.
>Concordia University
>

I have solved a similar problem to this without using multitasking
software on my host PC. Multitasking is only required because you are
tackling the problem by leaving the transputer fileserver running to
access the I/O facilities of the PC from the transputer network. 

I was able to solve the problem by terminating the fileserver after
booting the transputer network and incorporating code into my single-task
PC program to exchange data with the transputers. This was made very much
easier because I used a TMB16 transputer motherboard from Transtech - this
is sold with a software package that includes a device driver for
accessing the transputer network. Furthermore this board uses a 16bit
interface in contrast to the 8 bit interface of the INMOS B008 standard.
It also has backwards compatibility with the B004 and B008 standards if
required. Data transfer rates of 1.25MBytes/sec can be achieved between
the PC and the root transputer.

I have written a C function library to allow me to send and receive
characters, strings, integers etc between the PC and the root transputer.
I did not need access to the PC file system in my application but the
Transtech software package includes Occam, Inmos C and 3L-C libraries
for these functions.

My PC code includes a polling routine which exchanges a flag with the
transputer network even when no data is being exchanged so that the PC and
the transputers can 'know' when the other is functioning correctly and
take suitable action if not e.g. if the user wishes to terminate operation
from the PC keyboard. 

It may be that you are already committed to a specific transputer hardware
arrangement (particularly the motherboard) in which case this solution may
not be possible. However, if you would like more info then email me.

Cheers - Dave.
-- 
!=========================================================================!
! Dave Glennie   email: david.glennie@ncl.ac.uk   tel:  ++ 44 91 2227820  !
! University of Newcastle, UK                     fax:  ++ 44 91 2228600  !
!=========================================================================!
