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Re: CG14 in 8-bit color

Is there any interest in 16 bit color?  It might be more compatible than 8 bit with some programs and still allow for the highest resolutions even with a 4MB VSIMM.  The cg14 can be coerced into either 565 or 555 mode by abusing pretty much all of its lookup tables at the same time.  Very unlikely to have any acceleration with this mode though.


On Sun, Nov 7, 2021, 11:19 PM Michael <macallan%netbsd.org@localhost> wrote:

On Sun, 7 Nov 2021 08:31:15 +0100
Malte Dehling <mdehling%gmail.com@localhost> wrote:

> admittedly it doesn't seem that useful, but I run my cg14 in 8-bit color
> to allow for higher resolutions (1920x1200).  "Out of the box" the Xorg
> driver included with NetBSD 9.2 works only in 24-bit color; with a few
> changes to xsrc/external/mit/xf86-video-suncg14/dist/src/cg14_driver.c
> it works in either 8-bit or 24-bit mode.  I've attached a diff.  Simply
> set DefaultDepth in xorg.conf or use the -depth command line parameter.
> Part of the change is to trust the OBP on the VSIMM size instead of
> assuming an 8MB VSIMM for higher resolutions.  I'm not sure if that
> breaks anything?  (Older OBP versions?  The SS10SX?)

That's from Way Back When OBP access didn't work at all on NetBSD ( or
rather, the NetBSD-specific SBus support code in Xorg was rather
horribly broken. No idea how that happened. )
I fixed it a while ago, so this workaround can go away.

> I also have no clue how to fix the acceleration code.  Currently if you
> enable the Accel option, you will see vertical bars on your screen
> (looks like 3 black pixels followed by 1 pixel of the actual image.)

Yeah, the accel code pretty much assumes 32bit colour. I'll fix that.

> With ShadowFB enabled I find the speed acceptable, but of course
> acceleration would be preferable.

SX isn't *that* fast, especially compared to anything halfway modern.
It should be able to shovel data around faster than the CPU alone

have fun

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