[Oberon] RGB display in Oberon RISC5

[eas lab]

Since there are readers here who have looked down into the details of RGB,
I'll mention that a had a bad problem with a <1920 ? 1280> LED display,
but only with my prefered linux installation, and only after it had
gone into <sleep mode, from non-usage>.
I wasted a lot of time/effort to try to understand to cause, which seemed to
be related to <gamma ?>. Never found the cause, and just found a hack to
prevent sleep mode.

There's an ETHO Panel which has a <color circle>, at the lower RHS corner,
which was MOST usefull.
It showed how the R,G,B where <bleeding> into each other at the.
<lower levels>  which gave grey-to-white, for much of the circle, instead
of only white in the middle - where the R,G,B have the same magnitude.

Primary-color text was OK; but pdf and ETHO became all fuzzy.

My point is that <little ETHO> provided a tool which I couldn't find
else where.

== Chris Glur.


On 4/19/16, Magnus Karlsson <magnus at saanlima.com> wrote:
> https://en.wikipedia.org/wiki/Additive_color
>
> R   G   B         colour
> 0   0   0           black
> 0   0   1           blue
> 0   1   0           green
> 0   1   1           cyan
> 1   0   0           red
> 1   0   1           magenta
> 1   1   0           yellow
> 1   1   1           white
>
> Magnus
>
> On 4/19/2016 1:06 PM, thomas.kral at email.cz wrote:
>> Magnus,
>>
>> That is great, now we can see Oberon is capable of supporting more
>> colours, not sure how they are coded
>>
>> R   G   B         colour
>> 0   0   0           black
>> 0   0   1           ?
>> 0   1   0           ?
>> 0   1   1           ?
>> 1   0   0           ?
>> 1   0   1           ?
>> 1   1   0           ?
>> 1   1   1           white
>>
>> There are four bits used as you say,
>>
>> bit 3: not used
>> bit 2 : R
>> bit 1 : G
>> bit 0 : B
>>
>> Many thanks
>> Tomas
>>
>> ---------- Původní zpráva ----------
>> Od: Magnus Karlsson
>> Komu: oberon at lists.inf.ethz.ch
>> Datum: 18. 4. 2016 22:29:54
>> Předmět: [Oberon] RGB display in Oberon RISC5
>>
>> 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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>
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