Re: Blech! How can you stand 640x200??

[Rubywand <rubywand@swbell.net>]

"Mr. Boffo" writes ...
> 
> So anyway I've been trying out stuff like Hyperstudio for the IIgs,
> and the one thing which keeps coming to mind is: "Boy, this screen is
> just godawful!"
> 
> What exactly was the point of limiting the IIgs to a maximum of
> 640x200? The pixels are so irregularly shaped that the screen images
> look horrendous. At this point my only guess is that memory cost too
> much for the extra resolution to be worthwhile.
> 
> Now, the 320x200 mode is just fine and dandy. That mode is quite nice.
> But 640x200 totally blows. The text looks terrible, unless you make it
> double wide to compensate for the unnatural skinniness that 640x200
> imposes on everything.
>

     While 640 x 200 is far from ideal, the resulting display is not all that
horrible. Really, the biggest limitation is on the number of colors per
palette-- just 4.

 
> This reminds me of something that's always bothered me.. how is it
> that the image appears to really only have 200 lines, when NTSC is
> really 525 lines? I realize the edges are blank and unused to prevent
> overscan, but still, at 200 scanlines tall you'd have a squashed
> letterbox in the middle and 162 blank scanlines above and below.
> 
> It would seem that those 200 image scanlines are double-thick, yet
> when you look at the graphics on an NTSC monitor you can't tell that a
> pixel is two scanlines tall. Even with the old hires 280x192 grahpics,
> a pixel appears to be made up of a single scanline, with a definite
> separation from the next pixel above and below but no visible split in
> the pixel itself. Is this really a "normal" NTSC resolution at all?
> 
 ....

     No; it is a plain non-interlaced RGB setup. The reason you do not see a
separation between lines is dot size. Dot pitch for the CRT is .37mm, a good
deal larger than modern SVGA CRT ratings of .25mm or smaller. Lines on the IIgs
monitor are fat enough so that 200 lines fill most of the screen with no
obvious separations.



Rubywand