Re: [hatari-devel] VDI 2-planes mode

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On 06/03/2013 23:50, Eero Tamminen wrote:
However, in TT & Falcon mode EmuTOS for some reason selects 16-pix font
for >=400 high 4- & 16-color modes, although it doesn't do that in ST/e
mode.  Do you know the reason for this inconsistency?

The OS selects the right font according to the boot video mode.
What you describe is what I intended with the NVRAM hack.
With big resolutions (>=400 high), the big font is selected.
You will probably agree that this behaviour is consistent with standard resolutions.

Unfortunately, on ST the boot video mode is quite limited. It can be either ST_LOW or ST_HIGH.
For extended color modes, we have to boot in ST_LOW, with the small font.
For extended mono modes, we have to boot in ST_HIGH, with the big font (even in small resolutions).

The problem with this inconsistency in EmuTOS is that to avoid
crashes when BIOS console writes text at screen bottom,

This should not happen.
The number of text rows must be related to full rows, not partial ones.
Maybe Hatari does not correctly round down the number of text rows when hacking the Line A variables?

1. constrain resolution height to be aligned to 16-pixels
    (currently it's 8-aligned for other than mono modes),

When the rule above is respected, I don't think any height constraint would be necessary. Even 1 pixel alignment should be fine. In GEM there is no trouble, and on the BIOS console there will be a small horizontal area unused at the bottom. Maybe that small stripe would not be correctly cleared when switching from GEM to BIOS console, I don't know.

Anyway, forcing the height to a multiple of 16 when it is >= 400 makes sense, since that will avoid that small stripe at the bottom, in any case.

Vincent Rivière

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