[Coco] [coco] video signal generation

[RJRTTY at aol.com]

People

I have  been struggling with a problem with my converter for a while
and I need some  information.
Does anybody know the details of how the GIME  generates a
RGB video signal?   The problem I am having is that  while 80 col
text on the green channel is clear and sharp, 80 col text on the  red shows
some video degradation and 80 col text on the blue channel is  completely 
illegible.

What I am thinking is that the GIME generates the  green channel first, the
red channel second and the blue channel  last.   Is this correct?   Another
strange thing is that  80 col text in any color combination that has even a
little green in it shows  up well but if you look at 80 col. text using pure
red or blue as the  foreground or backround you get a wierd kind of video
smearing.

I  already have a solution.  If a low pass filter is placed in the input  
channels
the 80 col text shows up well in all color combinations.    In other words I 
had
to DECREASE the bandwidth of the converter in order to  get acceptable 
results.   It seems that the quality of the video  signal coming out of the
GIME in the coco3 is only slightly better than the  old monitors could display
and the high bandwidth of my converter is just too  much for the signal
showing it "warts and all".

I don't know about the  rest of you but purposely degrading the converter to
approximate the  perfomance of the old monitors just seems wrong to me.  The
image does  soften a tiny bit with the filters but not enough to notice if you
were not  already looking for it or directly comparing it to an  unfiltered
converter.

Does anybody know what is going on with the  conversion process in the
GIME to cause this?

TIA
Roy