Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!microsoft!brianw
From: brianw@microsoft.UUCP (Brian Willoughby)
Newsgroups: comp.sys.apple
Subject: Re: Interrupt handling with a modem in CP/M
Message-ID: <7011@microsoft.UUCP>
Date: 20 Jul 89 04:56:04 GMT
References: <1622@sactoh0>
Reply-To: brianw@microsoft.UUCP (Brian Willoughby)
Organization: Microsoft Corp., Redmond WA
Lines: 25

In article <1622@sactoh0> ianj@sactoh0 (Ian R. Justman) writes:
>I need some help with writing a driver for a communications program
>when using CP/M.  ...
>wrote an interrupt handling routine which is activated when a
>character comes in and shoves the character into a circular buffer
>within the driver space (it is 256 characters long, BTW...).  Even
>with that in place, I still lose characters ...
>-- 
>Home:   Ian Justman       |UUCP:                 |"One of the few

Try doubling the circular buffer size and rewriting the interrupt
routine.
How does the interrupt routine handle buffer full condiitions?  Are you
detecting when the buffer fills?  My interrupt routines increment a LOST
count every time a new character interrupt tries to add a character to a
full buffer.  Then, when my program is running, I can check this value
and print an error message showing how many characters were lost.  If I
see the error message, this is a sure sign that I need to increase the
buffer size for that application.

Brian Willoughby
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