alangenh: you know what? I think I was right the first time...you should be able to specify a DPI for each monitor (specify DisplaySize as whatever you want). Details here:
http://wiki.archlinux.org/index.php/Xorg#Display_Size.2FDPI
AFAIK Mac OS X also uses (or can use) X11/Xorg so if it's possible in Linux it will very likely be possible in Leopard.
Why don't you give a free Ubuntu (ppc arch) Edgy LiveCD a try and find out? I don't have a free second monitor here to test it out. I'll see what I can do tomorrow with the secondary input on my screen, as each input on the monitor is considered another "monitor" in theory.
Here was my reply before I realized that:
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Originally posted by: alangenh
I'm kind of wondering if resolution independence (which the next Mac OS and Vista, last I heard, will have) will help or not. To read what Apple is telling developers about it, search for "resolution independence" on this page:
http://developer.apple.com/leopard/overview/
I think what they are saying is that glyph (font character) size will be specified in metrics (physical units, as opposed to arbitrary ones such as pixels, twips, or point). That's certainly a good idea, but it will fall apart when you enable clone mode on a dual monitor setup. Clone mode is done at the video card level. The image for the screen is rendered and sent to the video card. The video card then duplicates it and sends it out the second video port. At that point, no vector data exists. It is all a flat raster image to which no true font scaling can be performed.
Now they could get around this by sending a separate screen to each port and then scaling the second screen, but then, providing your LCDs are running at different resolutions (or physical sizes in this case), the screens would be out of sync since the higher resolution screen could hold more GUI content. I don't know what would happen then, but I suspect they will never get to that point. I don't think the feature will exist as it will be way too complicated to implement.
I can only imagine what a nightmare you're having squinting trying to read the text on the laptop while trying to read the monitor at the same time. Ouch...are you sure you don't just want another desktop LCD? I like high-DPI TFTs as well, but as implemented in laptops they tend to be eye-strain inducing not only due to the small font size, but the poor contrast and TN panel...maybe you should just hook up the 215TW, close the lid, and call it a day? It just seems like it would be pretty hard on your neck with that kind of config. If you need more desktop area the best thing to do is to invest in another desktop LCD. If you decide to go that route, the
Samsung 205BW would be a good value LCD. I know that's gotta be hard to justify after putting in ~$500 toward the 215TW, and you probably didn't expect me to recommend you another LCD, but from the perspective it's the only thing that makes sense here. I would either use only the 215TW or get a complementary LCD.
Zooming is easy for one file, but for tons and tons of files, it's too much trouble for that to be a good solution. I tend to go through browser tabs like a crazy crazy thing, and also programming terminals. I also live in macjournal, which is an interface to what amounts to tons of text files. I want to be able to use that last one in either monitor, but I don't want to constantly have to re-zoom the text size on all those individual text files.
It's probably just something that'll take some getting used it, and then it'll stop bothering me. I will probably learn to only use a web browser and macjournal on my laptop screen. I can probably set up two keyboard shortcuts for terminals of different configurations depending on which monitor I'm aiming at, and that will help. I probably shouldn't get too excited about resolution independence at this stage of the game, but I hope it will help.
FYI,
215TW: 93 PPI
macbook: 112 PPI
The numbers don't look that different, but it's enough to make me wish the 215TW was 112 PPI.