[Oberon] RGB display in Oberon RISC5

[Tomas Kral]

Hi Joerg,

Using palettes would utilise memory better while offering more colours.
This would also possibly bring it close to Ceres-2. The two procedures
bellow taken from Display.Def of Ceres-2 project, do they imply the use
of a colour map (palette)?

PROCEDURE SetColor*(col, red, green, blue: INTEGER);
PROCEDURE GetColor*(col: INTEGER; VAR red, green, blue: INTEGER);

From H/W point of view, could it  be more difficult to implement in
Verilog?

Tomas
-- 
Tomas Kral <thomas.kral at email.cz>

On Tue, 2016-04-19 at 09:12 +0200, Jörg Straube wrote:
> Hi Magnus
> 
> Thx for preparing VID.v
> As the original ProjectOberon has only 1M of memory, it's a pity to waste 25% of your 4 bit color layout. Basically, we could use 16 colors instead of 8.
> Instead of mapping the bits directly to RGB, I would rather use the 4 bits as index into a color palette.
> 
> Display.Mod has to be adapted accordingly.
> 
> Jörg
> 
> > Am 18.04.2016 um 21:59 schrieb Magnus Karlsson <magnus at saanlima.com>:
> > 
> > I have made an updated version of VID.v with support for an RGB video buffer.
> > 
> > The video buffer is now 4x larger (about 40% of the total 1 MB RAM) and video refresh will use up about 40% of the memory bandwidth.
> > 
> > See http://saanlima.com/forum/viewtopic.php?f=14&p=1786#p1783 for Verilog code and bit files for Pepino_LX9 and Pepino_LX25.
> > 
> > Magnus
> > --
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