PS2Linux framebuffer console dslpay

SDL Development
1

There are problems on PS2Linux regarding display using
the framebuffer console. If anyone else has any ideas
as to why they are happening, I might be able to work
some way towards building a patch…

OK, the first thing that is strange is that video mode
changes are only acted upon the 2nd time you run the
program after the change… let me explain.

The PS2 boot up in 640x240 PAL non-interlaced.
I run my SDL game, it detects this mode.
I change the video mode to 640x480 PAL interlaced
I run my SDL game, it detects 640x240 non-interlaced.
I quit and run the game again, it detects 640x480
interlaced.

No, I really want to be using the frame-buffer console
rather than an X window as the PS2 only has 32Mb of
RAM, and X takes up too much of it. IT also seems to
default to a window size larger than my screen, but
that’s another story.

The 2ns problem with video modes is a lot stranger.
In 640x240 non-interlaced, the left hand edge of the
window is actually in the middle of the screen, and
the display wraps around so that the right hand edge
of my window is also at the middle of the screen, i.e.±-----------+

  • TITLE +
  •        +

  •        +

  •        +

±-----------+

becomes

±----+±----+

  • ++   TI+

+TLE ++ +

  • ++     +

  • ++     +

±----+±----+

So, to try to fix this, I adjusted the screen
resolution height to 640x250, or 640x256. I can’t
remember the figures off hand, but some heights caused
bizzare patterns of display, whilst some came out with
pictures contiguously correct, but not centered.

Any ideas where SDL is going wrong, and how it can be
fixed? I’m happy for now forcing my display to
640x256 non-interlaced, but obviously this would not
be a good display mode for an x86 box, and I would
like to keep some cross-platformness in my game!

Thanks for any comments

PS According to another user on the PS2Linux site,
this also happens in NTSC mode. I don’t yet know
about VESA mode (Yes, you can plug the PS2 into some
monitors :slight_smile:

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2

Hi Paul

I also saw these issues while porting Spheres of Chaos
(http://www.chaotica.u-net.com/page/dnld_ps2.htm)

becomes

±----+±----+

  • ++   TI+

+TLE ++ +

  • ++     +

  • ++     +

±----+±----+

So, to try to fix this, I adjusted the screen
resolution height to 640x250, or 640x256. I can’t
remember the figures off hand, but some heights caused
bizzare patterns of display, whilst some came out with
pictures contiguously correct, but not centered.

I think this is because NTSC and VESA modes are 4\3 pixel ratio, PAL is
5\4 sizewise (in implementation 4\3 though still I think… but not
square pixels I believe…)

On consoles we use 320x256 and 640x512 for PAL resolutions, respectivly
equal to 320z240 and 640x480 (NTSC) to make use of the extra vertical
resolution available in PAL.

Any ideas where SDL is going wrong, and how it can be
fixed? I’m happy for now forcing my display to
640x256 non-interlaced, but obviously this would not
be a good display mode for an x86 box, and I would
like to keep some cross-platformness in my game!

On PS2Linux the setcrtmode command can change the TV/VESA format output:

vesa0[,{60|75}] same as 'VESA 640x480 [60Hz|75Hz]'
vesa1[,{60|75}] 'VESA 800x600 [60Hz|75Hz]'
vesa2[,{60|75}] 'VESA 1024x768 [60Hz|75Hz]'
vesa3[,{60|75}] ‘VESA 1280x1024 [60Hz|75Hz]’

ntsc0 'NTSC nointerlace’
ntsc1 'NTSC interlace’
pal0 'PAL nointerlace’
pal1 'PAL interlace

Of these I saw the same effect as you only with pal0, This is I
suspect because 640x480 fits into a pal1 640x512 resolution display fine.

PS According to another user on the PS2Linux site,
this also happens in NTSC mode. I don’t yet know
about VESA mode (Yes, you can plug the PS2 into some
monitors :slight_smile:

In my case ntsc0 and ntsc1 output worked fine, chaos was compiled to use
640x480, perhaps SDL changed the resolution of the TV from ntsc0 to ntsc1?

After buying a PS2 VESA adapter that outputs to standard non-SoG RGB I
have it working with a monitor as well now. (hk-success.com)

Cheers

JG