Mangelore's RGBi/CGA/VGA modification

[redrumloa]

First off, thanks to Fotios for figuring out this mod in the first place! As I'm sure you've seen, a few colors are off.

Mainly:
Orange looks dark purple
Dark Grey looks light blue

Has anyone figured out how to fix this? Thanks in advance!

[redrumloa]

After some playing, I'm thinking of replacing the built in potentiometers. The ones that come on this board only go to 1K Ohm and after tinkering I think increasing resistance may bring colors in more.

[redrumloa]

Umm.. Maybe I took stupid pills this morning. I just hooked up my 1902 and the colors look like they are close to the same. I'm going to take a pic of the 1902 image and compare to the adapter output.

[redrumloa]

color palette on a 1902.

[redrumloa]

Ok here is the VGA output, after tinkering with the pots a bit.




Closer than I was thinking, mainly only color 11 is off. Quite doable as-is.

[Andrew Wiskow]

First off, thanks to Fotios for figuring out this mod in the first place! As I'm sure you've seen, a few colors are off.

Mainly:
Orange looks dark purple
Dark Grey looks light blue

Has anyone figured out how to fix this? Thanks in advance!

It's not a matter of fixing anything...  The 16 colors in 80-column mode are different than the 16 colors in 40-column mode.

These are the most noticable differences:

40-column "purple" looks like "hot pink" in 80-columns.
40-column "orange" looks like "dark purple" in 80-columns.
40-column "brown" looks like "puke tan" in 80-columns.
40-column "pink" looks like "bright red" in 80-columns.
40-column "dark gray" looks like "dark cyan" in 80-columns.
40-column "medium gray" looks like "dark gray" in 80-columns.

These color names are, of course, my own opinion...  I don't think you'll find a crayon that's labeled "puke tan". 

-Andrew

[Golan Klinger]

I don't think you'll find a crayon that's labeled "puke tan". 

Heh.