Any changes I make in the dosboxPHANT.conf don't seem to do anything. Why is this?

If your on vista or windows 7 open notepad as an administrator by finding it under the start menu --> accessories then right click it and run as administrator. Then load up the dosboxPHANT.conf and make your changes, save the changes and now it should keep whatever you changed.

7. Yeah. I edited and saved the file correctly. For instance, if I change the scaler setting to SuperEagle (whatever it's called) or scanlines, I notice no changes when I start the game again.
I haven't played with the setting a whole lot, but thought maybe someone else has.

Just a note, here. While the different scaler options are a matter of taste and should be adjusted to what looks good to you, there is no use in setting aspect=true, as this VESA game does not need aspect correction and will not make any visual difference. The use of aspect correction is for the EGA and older VGA games that were based on aspect ratio of 320x200 as apposed to the 640x480 used in later games.

wow, that is really awesome! thanks Qbix:)

Thanks Qbix.
So, I want this particular game to look like it did when I played it on that CRT.
I changed line 54:
scaler=rgb2x forced
rgb3x doesn't work; the game doesn't start. But, the rgb2x effect is good. Now, I want the game to be in it's intended aspect ratio and have the RGB effect applied evenly without moire effect. I got it to do this, but...
Now, here's something I don't understand, but works. I changed line 21 to:
fullresolution=forced 1280x1024
I don't think "forced" is correct syntax-wise in any way in there. I can put anything before "1280x1024", but something has to be there. "1280x1024", "original", or "1280x1024 ?????" do not work. "dudes 1280x1024" works. I don't even...
So:
21 fullresolution=forced 1280x1024
54 scaler=rgb2x forced
-looks like an old monitor to me. It makes me hate that orange-ish shirt like it's the first time... again... for the first time.

In Phantasmagoria, how can I make the game take up the entire screen?

By default, the games on GOG are usually full screen. Perhaps yours is set up for a window or at too high a resolution. Perhaps you could try ATL-ENTER? In games somtimes, it can switch you from window to full-screen and back again.

I'd like to update this topic for anyone who has newly downloaded the game. There is a program in the phantasmagoria folder under gog games called "Launch Graphic Mode Setup."

Double click on this. Go to "Advanced Settings" Change scaling engine to scan 3x, or other setting (experiment to find what you like best) change the resolution to the native resolution on your computer and you are all set. Press ALT + ENTER when game starts to make window full screen.

Hope that helps.

Tex