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Path: utzoo!dciem!nrcaer!xios!!chris
From: chris@.UUCP (Chris)
Newsgroups: comp.sys.ibm.pc
Subject: DOS and INT 28 and DOS BUSY FLAG - Help please
Message-ID: <479@.UUCP>
Date: Wed, 18-Nov-87 21:03:21 EST
Article-I.D.: .479
Posted: Wed Nov 18 21:03:21 1987
Date-Received: Thu, 26-Nov-87 23:48:26 EST
Organization: XICOM Ottawa,Ont. Canada
Lines: 14
Summary: Multitasking with DOS

References:


This topic may have been covered before but I'm quite new to the usenet  
and am having trouble getting several TSR (Terminate/Stay Resident)
programs to co-operate.  In my INT 21h intercept routine, I use the
DOS_BUSY_FLAG, (obtained using INT 21h Function call 34h) to determine
if DOS can be used.  If it is in use I wait for either a) an INT28 to
occur which tells me I can go ahead and use DOS, or b) the 
DOS_BUSY_FLAG to go to zero (I am only examining a byte location). The
problem is that other TSR's (like DOS' print) will not run.
QUESTION: Do I have only half of the equation?  If you can help me with
this I'd appreciate it....

Thanks from Chris Ellis (chris@xicom.UUCP)
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