Re: [hatari-devel] TOS issues with VDI mode (was: I'm back)

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On 11/8/20 12:16 AM, Miguel Saro wrote:
> I try last binary Hatari and I compare with old (I compiled). I set same preferences.
> problem: with 2.2.1 I cannot reduce the width of window C

After some testing with VDI mode, I was able
to reproduce this issue in original TOS.

It requires:
* 2-plane VDI mode
* >=400 screen height

There's a similar bug in vertical direction with:
* 1-plane VDI mode
* <304 screen height


Background:

Besides setting screen dimensions related
Line-A and VDI variables, VDI mode selects font
based on screen height (<400 -> 8x8 font,
>=400 -> 8x16 font), and sets font size related
OS variables.

Original TOS versions don't handle all kind of
screen & font size combinations.  EmuTOS does.


=> If you want to use such VDI modes, please use
   EmuTOS. It can handle more screen attribute
   variations than original TOS.


I'll add note of 2-plane issue to docs, and
prevent in Hatari code VDI heights causing
1-plane issue.


	- Eero