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From: mjw06513@uxa.cso.uiuc.edu (Mary J Winters)
Newsgroups: comp.sys.ibm.pc
Subject: DoubleDOS Chokes on BIOS Calls?
Keywords: DoubleDOS DDOS BIOS
Message-ID: <1989Dec7.155828.4583@ux1.cso.uiuc.edu>
Date: 7 Dec 89 15:58:28 GMT
Sender: news@ux1.cso.uiuc.edu (News)
Reply-To: mjw06513@uxa.cso.uiuc.edu (Mary J Winters)
Distribution: na
Organization: University of Illinois at Urbana-Champaign
Lines: 18



I've written a program which calls the BIOS INT 10h functions to do screen
output. The program runs fine when it is alone on the machine, and also runs
fine under DESQview. When I attempt to run it under DoubleDOS, however, I get
very strange results: My program and DDOS seem to conflict whenever my program
writes to the screen. I see several characters appear briefly on the screen,
but they are erased almost immediately. Then a few more characters appear, and
they are also erased. This process continues for some time, as the speed of the
output also appears to be slowed tremendously.

The reason I chose the routines I am using is because they use the BIOS 
exclusively for character I/O and cursor positioning, and I was under the
impression that this method is supposed to be the most compatible with 
multitaskers. What am I missing here? I'm using INT 0x10, function 2 to move
the cursor and INT 0x10, function 9 to write the characters. 

Your assistance will be most appreciated.