[comp.sys.ibm.pc.misc] Meridian Ada and IBM PC serial ports

mfeldman@seas.gwu.edu (Michael Feldman) (01/23/91)

In article <mskuhn.664466478@faui09> mskuhn@faui09.informatik.uni-erlangen.de (Markus Kuhn) writes:
>I am developing an (public domain) application with Meridian
>Open Ada 4.1 (was AdaZ) with lots of pre-emptive tasking
>and access to the serial ports (an OSI system!).
>
>Can this problem also be solved with Meridian's interrupt
>entry mechanism? Somebody wrote here a few weeks ago that this
>would be to slow.
>
I assume you have access to the AdaZ documentation. Their DOS Environment
Library has a package called Interrupt. Gives you direct access to the
DOS interrupts without using the "right" Ada way to do it, which is the
interrupt entry. Looks similar to what you're used to in TP.

I have no idea what the comparative timings are. There is a commonly-held
view that ANYTHING done with the Ada tasking constructs MUST be much
slower than doing it "the old way" without tasking. This seems to be true
sometimes, but not always.

I'd be VERY interested in seeing a comparative implementation of (a
simple version) of your program, done both ways. I think the net would be
interested as well. If you can get this working, we'd all appreciate your
posting the code. Try something simple first.


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Prof. Michael Feldman
Department of Electrical Engineering and Computer Science
The George Washington University
Washington, DC 20052
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mfeldman@seas.gwu.edu
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