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From: chin-lon@puff.UUCP
Newsgroups: comp.sys.amiga
Subject: Question on Serial Interrupt Servers
Message-ID: <664@puff.WISC.EDU>
Date: Sat, 18-Apr-87 13:51:57 EST
Article-I.D.: puff.664
Posted: Sat Apr 18 13:51:57 1987
Date-Received: Sun, 19-Apr-87 02:15:04 EST
Organization: U of Wisconsin CS Dept
Lines: 28
Keywords: amiga serial interrupt

After reading the example on how to use the parallel port interrupt,
I have the following question on the serial port. Hopefully someone
on the netland (commodore?) would respond:

I planned to write a serial interrupt handling routine for reading and
writing from/to the serial port. I've had success at doing this,
as I was able to both transmit and receive. But I do have one concern:
How can I be sure that when I do a SetIntVector(), that I'm not
taking over someone else's interrupt handler (belonging to the
serial.device, say). In other words, I want to set the interrupt
server only when no one else has one set up.

This issue brings to a more general problem of coordinating between
different programs using the serial port. Suppose that there are
a number of programs, all talking to the same instrument attached to the 
serial port, with each wanting to use the serial port only for
brief durations in its existence. Some programs can make do with
the serial.deivce, while others need to set up their own interrupt handlers.
How can they be coordinated?

Any help is very much appreciated.

Chin-Long Cheng
UW.Madison

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