@nubechecorre
I'm sure someone will provide the mathmatics but I remember when I wanted to create a weird mode (I think I wanted 640x512) I simply went into the Picasso96Mode prefs... selected a mode very similair to it and started experimenting with the editing of it... eg you get a test screen and keyboard controls to move alter the viewing size and location...
good luck
![](https://www.amigans.net/uploads/smil3dbd4e398ff7b.gif)
of course, make sure you have your card attached otherwise there'll be no modes for you to edit in this interface.
there's other buttons like interlace and doublescan, not sure if I toggles any of those however, probably unlikely though...
no sure what my 0S4 classic is operating under now... I think ultimately I gave up the pursuit to use as much screen as I could without stretching it... PAL is of course 512 where NTSC is 480... well, roughly in those resolutions I think...
Got in to those sorts of things when I used DCTV... any TV work I done I was using 736x566 overscan or something like that... and NTSC was smaller...
ANYWAY!