Re: [Linux-fbdev-devel] Re: status

[Geert U. <ge...@li...>]

On 25 Nov 2002, Johan Bolmsjo wrote:
> For what it's worth, the interleaved modes on atari works like this:
> 
> The bitplanes are interleaved on 16 bit big-endian word basis so if you
> have two bitplanes, bit 0 of the first 16 pixels would be in the first
> 16 bit word in the display memory, bit 1 of the first 16 pixels would be
> in the second word. With bit 0 I mean as masked out by & 0x0001 in C,
> and bit 1 as masked out by 0x0002.

Thanks! This is exactly the kind of information I needed!

I added simple unoptimized support for Atari interleaved bitplanes to fbtest.
When I know I got the basics right, I can start writing optimized drawing
routines.

Anyone who cares to give it a try? Just check out CVS module `fbtest' from
http://sourceforge.net/cvs/?group_id=908, type `make' and run `fbtest' for all
available color depths (use fbset first), and tell me whether it works.

If no one is left with an Atari with Linux/m68k installed, I can create a
ramdisk containing fbset and fbtest, so you just need ataboot and a kernel to
test it.

Thanks!

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@li...

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds