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From: myers@hpfcdj.HP.COM (Bob Myers)
Newsgroups: comp.sys.hp
Subject: Re: How can I configure my display type?
Message-ID: <17330027@hpfcdj.HP.COM>
Date: 11 Feb 91 17:09:52 GMT
References: <1922@ruunsa.fys.ruu.nl>
Organization: Hewlett Packard -- Fort Collins, CO
Lines: 32

>>  That the system can not determine what interface is connected to the
>>RBG cable is not a limitation. An analogy: The loudspeaker of your audio
>>system does not determine what you will hear, the tuner does.
>>The tuner will not know if the speaker is connected or not and will work
>>perfectly without a speaker and so will the interface without a monitor.

>The reason you want the computer to know what kind of monitor is connected
>to the video system's output is to allow the computer to program the video
>system's output to suit a variety of monitors that could be connected to that
>output. Even the Apple Macintosh (I think) can do that.

But only because different timings or formats are supported by the digital
hardware in question.  The HP graphics cards are all single-timing; for 
example, the 98547A supports ONLY the 1024x768 60 Hz timing, the 98550A is
ONLY the 1280x1024 60 Hz timing, and so forth.  Once this is determined,
it really doesn't matter which monitor is connected to the far end of the
RGB cable, other than making sure that the monitor can handle that video
timing.  Your choice is typically one of size only.  For a further example,
the 98547A can properly drive EITHER the 98785A (16" 1024x768) or 98753A
(19" 1024x768), but NOT the 98789A or 98754A (the 1280x1024 versions of these
same size monitors, respectively).

In the PC world, this issue is further complicated by the presence of 
"multi-sync" monitors which can adapt themselves automatically to a number
of timings; examples are the NEC 3D or 4D, or HP's 1187A.  These can handle
the outputs of a number of different display boards, but again it's knowing
the BOARD'S capabilities that are important to the system - not the monitor.


Bob Myers  KC0EW   HP Graphics Tech. Div.|  Opinions expressed here are not
                   Ft. Collins, Colorado |  those of my employer or any other
myers@fc.hp.com                          |  sentient life-form on this planet.