Quadra 700 Colour?

>
> Hello Tim,
>
>    TL> I'm running 16-bit X now on a Mystic CC. 
The A/UX
>      > FAQ, backed up by LowEndMac, indicates that
Q700
>      > internal video is capable of 24-bit video
(provided
>      > the VRAM of course).  So I don't see why it
wouldn't
>      > work.
>
> I had read that the hardware supported colour, but
wasn't
> sure if NetBSD's X server did (the mac68k part of the
NetBSD
> Web site seem sort of stale, talking about 1.5.2 in the
> future tense).  Thanks for the help.  Now to find a
USB->ADB
> mouse adapter! 

A couple of things.  The Quadra 700 can't do 16-bit, only
8-bit or 24-bit,
and AFAIK there isn't support for 24-bit color X in NetBSD
(at least the
last time I tried).  You can do 8-bit greyscale, but not
8-bit color
because I don't think they ever got color lookup tables
working right.

Also, I don't think anyone has ever made a way to hook up
any USB
peripherals to ADB.  Vice-versa, yes - you can get adapters
to plug ADB
keyboards and mice into computers with USB, but not the
other way around.

- Nate

nateportents.com wrote:
> A couple of things.  The Quadra 700 can't do 16-bit,
only 8-bit or 24-bit,
> and AFAIK there isn't support for 24-bit color X in
NetBSD (at least the

Buh?  You mean the (MacOS) control panel lists 16, 256, and
millions of 
colors...but not thousands?  That seems very bizarre.  If
you've got 
enough VRAM for 24 bit, why disable setting to 16?

> last time I tried).  You can do 8-bit greyscale, but
not 8-bit color
> because I don't think they ever got color lookup
tables working right.

Yeah, the mac68k color X server is borked in 8 bit color.  I
never tried 
8 bit gray.


Tim

-- 
Tim & Alethea
christtrek.org

> nateportents.com wrote:
>> A couple of things.  The Quadra 700 can't do
16-bit, only 8-bit or
>> 24-bit,
>> and AFAIK there isn't support for 24-bit color X
in NetBSD (at least the
>
> Buh?  You mean the (MacOS) control panel lists 16, 256,
and millions of
> colors...but not thousands?  That seems very bizarre. 
If you've got
> enough VRAM for 24 bit, why disable setting to 16?

It's not that it was disabled, it was just never
implimented - it wasn't a
design goal.  The Quadra 700 and 900 were the first Macs
with built-in
true color (this is 1990, remember).  Why compromise the
design by
supporting an inferior 16-bit bit depth?  I don't think
there was even
such a thing as a NuBus video card previous to 1990 that
supported 16-bit
either.  The Quadra 700 and 900 were primarily aimed at
prepress, and
nobody in prepress at the time was going to work in 16-bit. 
And when you
look into how they implimented the 24-bit, using a technique
known as
'chunky planar', it's not surprising they didn't do
16-bit:

h
ttps://developer.apple.com/technotes/hw/hw_26.html

>> last time I tried).  You can do 8-bit greyscale,
but not 8-bit color
>> because I don't think they ever got color lookup
tables working right.
>
> Yeah, the mac68k color X server is borked in 8 bit
color.  I never tried
> 8 bit gray.

8-bit greyscale works, and since it has the same brightness
dynamic range
as 24-bit color, it can display true-color (in greyscale)
with no
dithering.

- Nate