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From: frotz@drivax.UUCP (Frotz)
Newsgroups: comp.sys.ibm.pc
Subject: Re: determining cga, ega, vga
Message-ID: <255F5647.6E1E@drivax.UUCP>
Date: 14 Nov 89 00:03:18 GMT
References: <5695@lindy.Stanford.EDU> <8019@cg-atla.UUCP>
Sender: frotz@drivax.UUCP
Reply-To: frotz@drivax.UUCP
Organization: Digital Research, Monterey CA
Lines: 29

fredex@cg-atla.UUCP (Fred Smith) writes:

>In article <5695@lindy.Stanford.EDU> GG.DAR@forsythe.stanford.edu (Aaron Reizes) writes:
>>How do I determine the type of video adapter installed,
>>CGA, EGA, or VGA?  So far I haven't found any easy way to be sure
>>which I am dealing with?

>Earlier this year there were a couple of articles in Dr. Dobbs Journal which
>outlined a procedure for determining not only what kind of video adapter is
>resident in a PC, but also whether it has a color or monochrome tube
>attached (except for CGA where you can't tell). Sorry, I don't recall which
>issues, but it was in the column by Jeff Duntemann (or the late Kent Porter).
                                     ^^^^^^^^^^^^^^

>It is a simple algorithm, based on functions known to exist in the BIOS
>extensions implemented in each type of card.

I have done this from Jeff Duntemann's code.  However, this code will
not work on some of the clone EGA/VGA or other weird cards.  Iff you
are using IBM and 100% compatible video cards then there will be no
problem. 

The problem comes in when trying to correctly recognize a QuadHPG as
an EGA (because it is not quite a VGA) without believing that the
QuadHPG is a MDS Genius.  These are but two monitors that we have
in-house that have been problematic. 

--
Frotz