Path: utzoo!attcan!uunet!husc6!bloom-beacon!mit-eddie!bbn!rochester!ur-tut!ur-valhalla!jal
From: jal@valhalla.ee.rochester.edu
Newsgroups: comp.sys.ibm.pc
Subject: Need help with bug in DOS 2.1 program
Message-ID: <1344@valhalla.ee.rochester.edu>
Date: 17 Jun 88 14:10:43 GMT
Sender: usenet@valhalla.ee.rochester.edu
Reply-To: jal@ee.rochester.edu (John Lefor)
Organization: URochester Department of Electrical Engineering
Lines: 20

I have found a really odd bug in a program of mine when
running on a PC (floppies only) under DOS 2.1.

The program runs fine under DOS 3.x and works under DOS 2.1
if a Microsoft Mouse is attached.  If the mouse is not 
present (no mouse driver) the code hangs up on a Disk
write (Int 21h, functions 40H).  This write immediately
follows an LSEEK.  There is a prior Write which works 
fine.

Does anyone have any ideas as to what the problem might
be?  


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I program ... therefore I am.

John Lefor    	University of Rochester		Dept of E. Engineering
716-275-8265	jal@ee.rochester.edu		...!rochester!ur-valhalla!jal