Path: utzoo!censor!geac!torsqnt!lethe!telly!attcan!uunet!samsung!caen!zeus.engin.umich.edu!pong
From: pong@caen.engin.umich.edu (Bryan John Jalowitz)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Dual Monitor Switching
Message-ID: <1991Mar12.175839.1687@engin.umich.edu>
Date: 12 Mar 91 17:58:39 GMT
References: <1991Mar11.172914.4450@engin.umich.edu> <1991Mar12.133739.28811@cbnewsh.att.com>
Sender: news@engin.umich.edu (CAEN Netnews)
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Organization: University of Michigan Engineering, Ann Arbor
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In article <1991Mar12.133739.28811@cbnewsh.att.com> rkl@cbnewsh.att.com (kevin.laux) writes:
>
>	You're missing Int 10h Function 12h Subfunction 35h, the Display
>Switch Interface.
>
>	AH:	12h
>	BL:	35h
>	AL:	0	Initial external adapter off
>		1	Initial VGA on
>		2	Active adapter off
>		3	Inactive adapter on
>	ES:	Segment of Switch State area
>	DX:	Offset of Switch State area
>
>	The first time you switch displays you must use AL=0,1.  After that,
>you use a double call to AL=2,3.  The Switch state area is a 128 byte buffer
>and each display needs it own.
>
My documentation ("Programmer's guide to PC & PS/2 video systems", Microsoft
Press) says that this function is for PS/2 video systems.  I tried it 
anyway, in case the book's information was old, however I do not get a
successful return value.  I am using an AT clone with both cards on an
ISA bus.  Should this still apply?

Any other ideas?

Tony Whipple
Tony_Whipple@um.cc.umich.edu