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- Path: sparky!uunet!timbuk.cray.com!shamash!ems!hollywood.ems.cdc.com!tbruseha
- From: tbruseha@hollywood.ems.cdc.com (Tom Brusehaver)
- Newsgroups: comp.robotics
- Subject: Re: DOS in real-time, is there a problem?
- Message-ID: <31327@nntp_server.ems.cdc.com>
- Date: 22 Dec 92 14:36:26 GMT
- References: <1992Dec20.153543.537@doc.bmd.trw.com>
- Sender: sys@ems.ems.cdc.com
- Organization: Empros Systems International, a division of Ceridian
- Lines: 40
- Nntp-Posting-Host: hollywood.ems.cdc.com
-
- In article <1992Dec20.153543.537@doc.bmd.trw.com> nickgill@doc.bmd.trw.com writes:
- >Hello,
- >
- >I am looking for any information on DOS in a real-time enviroment.
- >Please e-mail me if you know of any leads on problems that occured
- >in a real-time environment or on embedded computers as a result of DOS.
- >Thanks,
- >Nick
-
- I once supported a real-time monitoring system in a factory that was
- on a [MS]DOS system. The whole thing was written in Turbo Pascal, and
- used a non-standard graphics display (NEC PC-8000), most of the
- comments in the code were in japanese, as were some of the function
- names (jikan=time).
-
- Bascially there was a central launcher program that would fork off the
- actual working tasks. The one task would read the inputs, and put the
- values in a shared memory area. The next task would process this
- fresh data. The next task was based on the current display desired,
- and would put the appropriate information on the screen. I think this
- task would also poll the touch screen (another mess in itself).
-
- The main screen would show a summary of the factory. The next screens
- would show the 5 individual areas. Then there was an individual item
- display showing status. There was also some end of month reports, and
- end of year reports.
-
- The biggest problem with this whole system was the polled nature.
- There were no event driven interfaces (although I suppose there could
- have been. The touch screen processor (yup, a whole processor
- dedicated to the screen), queued about 10 actions (touch, release 2
- actions, although drag didn't work, and my japanese wasn't good enough
- to figure out if it were possible). The actual problems were reported
- down a serial line, and that had a huge buffer also.
-
- Also if there were any loops, or any of the modules launched never
- came back, nothing got serviced. The display looked like everything
- was working, but something else would report that error.
-
- Tommy
-