What is the real Amiga Maximum overscan in PAL?

[Photon]

Thread Necromancy is the best!

So here are the basic concepts.

Workbench allows you select any resolution and expects you to connect a compatible display.

PAL is 576i. This is the signal standard.

Horizontally, you can have any number of pixels: 10 million, 1280, or 20. Since the signal is analog, the display and cable standard will do its best to resolve the pixel train output by the graphics chip.

A horizontal solution of 768px (in Hires mode) is selectable in Workbench and by the native video chips.

The interlaced and Hires vertical and horizontal resolutions are multiples of the Lores, non-interlaced resolution, the base resolution.

The base resolution is 384x288.

Not all displays can show this resolution because - overscan.

The display type that displays the most possible of an overscan resolution is a CRT monitor.

On a CRT monitor, adjusted to show as much as possible of the PAL image, 370x285 is possible of this theoretical 384x288. (See my previous post.)

[A4000Bear]

Many years ago I made a TV test pattern generator from an A1200 motherboard. I needed to get extreme overscan to get an accurate representation of a PM5544 pattern, in excess of overscan normally attainable in a standard PAL screenmode.

I achieved this by using moned to modify a Euro 36 monitor to provide a PAL super hires screenmode with extreme overscan, 1472x594. In 'ordinary' hi res, this equates to 736x594. It is possible to go even higher, by extending active pixels further into the blanking periods.

[jotd]

I read that maximum height in lowres (OCS, PAL) is 256 but is it easy to display and compatible on every monitor? is there any game using this y resolution?

I've converted a few portrait arcade games and managed to remove the scores (24 pixels) to display only 232 lines. At the time it seemed that 256 lines was difficult to achieve.

[ross]

Originally Posted by jotd

I read that maximum height in lowres (OCS, PAL) is 256 but is it easy to display and compatible on every monitor? is there any game using this y resolution?

I've converted a few portrait arcade games and managed to remove the scores (24 pixels) to display only 232 lines. At the time it seemed that 256 lines was difficult to achieve.

The maximum height for PAL in OCS is 287 lines, 286 usable and the last one with COLOR00 only.
Of course it depends on the display device how many it can display and how much you have to change the device parameters to see them..
But near 270 lines even the old CRTs do it quietly.

Edit: just checked out Pac-Mania, it uses 272 lines

[jotd]

ah great, my new project is more difficult to cut up vertically, so I'll use 256 lines. I'll probably need help for screen centering and all thanks.