[Oberon] RGB display in Oberon RISC5

[Jörg Straube]

We have to distinguish between the display HW capabilities and the SW API.

The API SetColor and GetColor imply only that the SW is using a color map.
Whether the display HW uses direct color or a color map is independent of this API.

Even with this API it's up to the interaction of Display.Mod and VID.v (or generally the display HW) whether we store the color index in the framebuffer or put direct colors (extracted from the SW color map) in the framebuffer.

Jörg

> Am 21.04.2016 um 08:55 schrieb Tomas Kral <thomas.kral at email.cz>:
> 
> 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
>>> --
>>> Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systems
>>> https://lists.inf.ethz.ch/mailman/listinfo/oberon
>> --
>> Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systems
>> https://lists.inf.ethz.ch/mailman/listinfo/oberon
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 2380 bytes
Desc: not available
URL: <http://lists.inf.ethz.ch/pipermail/oberon/attachments/20160421/5bc35ab4/attachment.p7s>