| Re: [hatari-devel] Videl HW tricks (was: Hatari 2.0 Patch + Videl problem) |
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Hi,
On 11/15/2016 12:17 AM, Nicolas Pomarède wrote:
-------- Message transféré --------
Sujet : Re: Hatari 2.0 Patch + Videl problem
Date : Fri, 11 Nov 2016 22:57:47 +0100
De : Nicolas Pomarède <npomarede@xxxxxxxxxxxx>
Pour : Mark Fechtner <mf@xxxxxxxxx>
....
While tinkering around with Hataris F030 emulation, I fired up
Terrorize Your Soul and noticed that the hardware trick I used in the
Z-Buffer thingy before the rotator doesn't work (see attached
PNG). Hatari stretches that column all over the screen, instead of
repeating it. IIRC I set the videl to a very narrow display width (64
pixels or so, memory's very hazy on that) - which resulted in the videl
repeating that amount of pixels until the right border. That's why it
looks like this on real hardware: https://youtu.be/SonTpLHEHKw?t=305
It seems to be 68 pixels wide.
I'm not sure if anyone else used this back then, AFAIK one of the very
rare hardware tricks on Falcon. Unfortunatly I don't think I have
sources left of that particular part. Hopefully that behaviour isn't not
that hard to emulate?
First we need to know in which exact conditions screen
content is repeated (instead of HW letting the CRT just
scale it).
Is there any documentation on that?
And is there anything similar for the vertical direction?
For example Toons' Yepyha demo:
http://www.pouet.net/prod.php?which=8584
Causes this kind of output from Hatari Videl emulation
during some of transitions between the demo screen:
WARNING: strange screen size 640x1 -> aspect corrected by 1x512!
WARNING: strange screen size 384x1 -> aspect corrected by 1x256!
WARNING: strange screen size 384x17 -> aspect corrected by 1x16!
WARNING: strange screen size 384x41 -> aspect corrected by 1x8!
WARNING: strange screen size 384x65 -> aspect corrected by 1x4!
WARNING: strange screen size 384x89 -> aspect corrected by 1x4!
WARNING: strange screen size 384x85 -> aspect corrected by 1x4!
WARNING: strange screen size 384x61 -> aspect corrected by 1x4!
WARNING: strange screen size 384x37 -> aspect corrected by 1x8!
WARNING: strange screen size 384x13 -> aspect corrected by 1x16!
- Eero