From: johnsd2@jec304.its.rpi.edu (Daniel Norman Johnson)
Subject: Re: Multiple Video (was: Re: 7.1 vs. OS/2 and Windows NT)
Reply-To: johnsd2@rpi.edu
Organization: Rensselaer Polytechnic Institute, Troy, NY.
Date: Fri, 9 Oct 1992 02:30:34 GMT

In article <1992Oct8.144319.13273@tamsun.tamu.edu>, dlb5404@tamsun.tamu.edu (Daryl Biberdorf) writes:
|> In article <#9tzcma@rpi.edu> johnsd2@rpi.edu writes:
|> >In article <4eoxNRS00YV949Gsxy@andrew.cmu.edu>, cj00+@andrew.cmu.edu (Carl B Jabido) writes:
|> >|> I think that neither OS/2 nor Windows has the ability to virtualize
|> >|> monitor 2 as part of monitor 1, producing one big monitor (a la mac). 
|> >
|> >They don't, from every account I've heard. There is supposed to be
|> >a board that lets u use 4 vga monitors, but they all have to be 4-bit
|> >deep and the same size. It isn't very usefull.
|> 
|> Why is this not "very usefull[sic]"?

It means that you cant use it to add monitors over time-you have
to get all the monitors at once. Wouldn't it be better to get a big
monitor in the first place?

|>  Granted, the Mac method of adapting
|> to different bit depths is more convenient (and it allows you to still use
|> internal video in conjunction with a video card), but most people who
|> realize from the start that they need multiple monitors (they *did* buy
|> a quad-VGA or quad-EGA card, right?) will probably buy 4 of the same type
|> of monitor as well.

It ALSO means you can have 4 8 bit or 24 bit video cards. I really
meant "all 4 bit" not "all the same". We aren't talking about 
4 video cards o' your choice- one drives 'em all.

(actually, maybe they CAN go lower but windows doesn't work too good
that way)

|> This doesn't sound at all like a real limitation.

I disagree; it is. 4 bit is ikky. :)

|> >Incidentally, it doesn't "virtualize monitor 2 as par of mointor 1",
|> >they are internally represented as separate (which is why they can
|> >have different depths), but QuickDraw knows how to deal with multiple
|> >monitors. Hence if you are so inclined its trivial to make (special) use
|> >of an extra monitor- you walk the monitor list until you find the
|> >monitors you want, then open windows in that part of the global space. But
|> >if you aren't the user can explicitly put windows on other monitors.
|> >Its real neat.
|> 
|> Internally, *all* video cards would have to represent them as separate,
|> since each monitor will have its own video memory associated with it, right?

No. Quickdraw could act like they were all one monitor. You request
the "screen size", it would give you a box that contained all the
monitors, and so on. It doesn't; if you ask for a general
screen size you just get the bounds of teh main monitor. You have
to fool around some more to get anything bigger than that.

|> In the case of the quad-VGA cards for use with Windows on a PC, the
|> 4 screens are virtualized into one large screen with a resolution
|> of (4*horiz res)x(vertical res), giving you a playing field that's four
|> times as wide.

Yup. That's different from what color QD does. Color QD can of course give
you the same large desktop, but it doesn't act like one big one. Example:
zooming doesn't zoom out over ALL of the monitors, just the one
containing the largest area of the window to be zoomed (according
to the interface guidelines; if you dont do anything to make this
happen it actualy zooms out over teh main screen. Grrrr)

|> Granted, it's most cool that QuickDraw deals with varying bit depths
|> across monitors, but I think it's mostly a non-issue in reality.  Heck,
|> I still know precious few people with multiple-headed Macs or PCs at all.

Me neither. But one species that is (Relatively) common is an SE/30
(or Classic II I suppose) owner with a color monitor on the side. This
is a trick windows can't do.

|> I'm not really advocating the PC here; I'm just trying to present correct
|> information.  I own and use a Mac.

Your info was correct, but I disagree with your opinions. And my info
was correct too, no? You make it sound like mine wasn't, and you
were correcting me when in fact you never actually contradicted me.

-- 
			- Dan Johnson
And God said "Jeeze, this is dull"... and it *WAS* dull. Genesis 0:0

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