Hi Tom.

16-Nov-03 07:27:08, Tom Walker wrote to Jasen Betts

  -> Should be more than 400, AIUI CGA ran at the NTSC sync rate and
  gave 200
 TW> line -> of display plus some overscan in each frame, interlacing
 TW> would give -> 400 lines...

 TW> Actualy It is in Theory 488 lines avaialble for the Picture. BUT
 TW> the Interlacing gives you the 488 lines with 244 line Resolution
 TW> dosen't it.

interlacing gives you real 488 line resolution but it works best with
moving, or smooth-edged images (and typical TV images are both)
where interlacing falls down is with slow refresh rates (NTSC TV gives 30Hz
which is very slow) and when stationary vertical details have sharp edges.

Interlacing works. if your can find the right software and a reasonably
good video card you can quadruple the pixel clock and run a standard VGA
monitor at the standard VGA 640x480 sync rate but at 1280x960 resolution
interlaced. you get twice as many lines and it looks great for displaying
photographs but put horizontal or diagonal pixel lines on it (eg windows,
or text) and they flicker annoyingly.

I only know how to do this on linux (or other unix) machines running
X-windows (specifically XFree86 version 3 or 4), if you have "root"
access to one I can give details.

 -=> Bye <=-
---